United States
Environmental Protection
Agency
Region V
230 South Dearborn
Chicago, Illinois 60604
November 1979
oEPA
Water Division
Environmental Draft
Impact Statement
Alternative Waste
Treatment Systems
For Rural Lake Projects
Case Study Number 5
Ottertail County Board
Of Commissioners
Ottertail County,
Minnesota
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VOLUME I
DRAFT ENVIRONMENTAL IMPACT STATEMENT
ALTERNATIVE WASTEWATER TREATMENT SYSTEMS FOR RURAL LAKE PROJECTS
CASE STUDY No. 5: OTTER TAIL COUNTY BOARD OF COMMISSIONERS
OTTER TAIL COUNTY, MINNESOTA
Prepared by the
UNITED STATES ENVIRONMENTAL PROTECTION AGENCY
REGION V, CHICAGO, ILLINOIS
AND
WAPORA, INCORPORATED
WASHINGTON, D.C.
Approved by:
n McGuire
ional Administrator
S. Environmental Protection Agency
November 1979
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DRAFT ENVIRONMENTAL IMPACT STATEMENT
OTTER TAIL FACILITY PLANNING AREA
OTTER TAIL COUNTY, MINNESOTA
Prepared by
US Environmental Protection Agency, Region V
Comments concerning this document are invited and should be received by
DEC 3 1 1979
For further information, contact
Mr. Alfred Krause, Project Monitor
230 South Dearborn Street
Chicago, Illinois 60609
312/353-2157
Abstract
A 201 Facility Plan was prepared for the Otter Tail Facility Planning
Area. The Facility Plan concluded that extensive sewering would be required
to correct malfunctioning on-site wastewater disposal systems and to protect
water quality.
Concern about the high proposed costs of the Facility Plan Proposed
Action prompted re-examination of the Study Area and led to preparation of
this EIS. This EIS concludes that complete abandonment of on-site systems is
unjustified. An alternative to the Facility Plan Proposed Action has there-
fore been presented and is recommended by this Agency.
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SUMMARY
CONCLUSIONS
Many of the on-site treatment systems in the Proposed Service Area
do not fully meet the minimum standards set forth in the County Shore-
land Management Ordinance for depth to groundwater, separation from
wells and surface waters, and size of septic tank of drainfield. The
extent and nature of problems resulting from noncomplying systems was
not fully documented in the Facility Plan. Studies carried out in this
EIS suggest that high groundwater flows may have a much greater impact
on actual system performance than full compliance with design standards.
These high groundwater flows (often 10 to 12 feet per day) are a
major reason at least some components of septic tank effluent reach
Otter Tail Lake. During a winter survey almost a one to one relation-
ship was observed between the number of septic leachate plumes in Otter
Tail Lake and the number of permanent residents. Although phosphorus
concentrations from certain plumes might be high enough to sustain local
algae growth along some shoreline segments, no study has yet established
a correlation between the two. Localized nitrate contamination of
groundwater is relatively uncommon and is not associated with any par-
ticular shoreline area; identified problems of this kind have usually
proven correctible by simple well or treatment system repairs.
No alternative should affect open water quality in Otter Tail Lake.
Round Lake and Long Lake may be affected by continued reliance on con-
ventional on-site systems throughout the planning period.
Future development in the Otter Tail Lake vicinity would be only
slightly affected by any of the EIS alternatives. Population increases
vary by only 9% within the whole range of alternatives. Second tier
development is unlikely with any of them.
There are substantial differences in the present worth and user
charges among the alternatives. User charges increase in direct propor-
tion to the extent of new sewers provided. In the more expensive
alternatives high local user charges could result in substantial dis-
placement pressure for the permanent population, particularly those on
fixed and lower incomes. Proportional increases in water quality would
not occur.
DRAFT EIS RECOMMENDATIONS
The Recommended Action in this EIS is the Limited Action Altern-
ative. Selection of this alternative is tentative; the configuration of
on-site systems may be modified by studies to be conducted by EPA during
August and September 1979. Until completion of these additional studies
and the detailed Step II design work described below, EIS Alternative 1
may also be retained as a contigent "backup" alternative. The Limited
Action Alternative would provide:
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o Repair and upgrading of existing on-site systems such as
septic tanks and filter fields along most of the Otter Tail
Lake shoreline. This would include replacement of 50% of
septic tanks or filter fields.
o Grey water/Black water separation along problem high ground-
water flow segments of Otter Tail Lake and its satellites.
For treating and holding black water (human toilet wastes)
area residents would have their choice of:
A. Deluxe low flow (2 quart flush), low noise (3 decibels
quieter) air compressor toilets, with 2000 gallon holding
tanks for human wastes only. At such flow rates the
tanks would need pumping only every six months for perm-
anent residents or every year for seasonal residents.
B. A large-tank composting toilet of the "Clivus Multrum ",
or other recognized type.
In both cases "grey water11 from showers, sinks, or washing
machines would be treated by the existing on-site systems, re-
paired as needed.
o Planning and organization of an On-Site Wastewater Management
District for the Study Area.
o Site-specific environmental and engineering analyses of exist-
ing on-site systems throughout the Study Area.
The Recommended Action would result in water quality improvements
similar to any of the other alternatives. Its present worth, however,
is only about two thirds, and its tentative local costs only about one
half of those of the Facility Plan Proposed Action.
State and local concurrence with the Recommended Action would mean
that three additional steps would need to be taken with respect to the
formation of a small waste flow or on-site district. To allow quickest
Step II funding, the applicant would:
o certify that the project would be constructed and an operation
and maintenance program established to meet local, State, and
Federal requirements, including those protecting present or
potential underground potable water sources,
o obtain assurance, such as an easement or covenant running with
the land, of unlimited access to each individual system at all
reasonable times for such purposes as maintenance, operation,
rehabilitation, and replacement, along with the permission to
carry out such work. An option would satisfy this requirement
if it could be exercised no later than the beginning of con-
struction.
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establish a comprehensive program for management and inspec-
tion of individual systems some time before EPA approves the
plans and specifications. Planning for this program could be
completed as part of the Facility Plan or an initial portion
of Step II design. The program would include as a minimum,
periodic testing of water from existing potable wells in the
area. Where a substantial number of on-site systems are in
use, occasional monitoring of the aquifer should be provided.
HISTORY
In June 1976, the Otter Tail Facility Plan was completed and was
submitted to EPA Region V by Otter Tail County acting as the Grant
Applicant for funding under the EPA Construction Grants Program. The
Plan proposed construction of a centralized collection and land appli-
cation treatment facility was prepared by Ulteig Engineers, Fargo, North
Dakota.
With respect to the existing on-site systems in the Proposed
Service Area, the Facility Plan reached the following conclusions:
o Unsuitable site conditions and inadequately constructed
on-site systems may be causing contamination of the ground-
water supply.
o High bacterial counts have been found at the outlet of the
Otter Tail River.
o Many of the on-site systems cannot meet minimum standards set
forth in the Shoreland Management Ordinance.
o Sanitary sewage should be collected by means of a centralized
collection and treatment system.
EIS ISSUES
Water Quality. Although indirect evidence was presented in the
Facility Plan indicating that there may be a water quality problem
resulting from malfunctioning on-site systems, the relationship between
deteriorating water quality and inadequately functioning septic tanks is
unsubstantiated. With the exception of well water samples showing high
groundwater nitrate concentrations, claims of public health hazards are
not documented. Modeling of Otter Tail Lake based on existing water
quality data, indicate that the on-site systems contribute a small
percent of the total nutrient load.
Cost Effectiveness. The collection system proposed in the Facility
Plan Proposed Action is estimated to cost $8.6 million or 83% of the
total cost. Since MPCA does not normally assign high grant funding
priorities to collector sewers, the cost of the collection system can
affect the local community more than other project components. There-
fore there was some incentive to consider alternatives to centralized
323 D3 iii
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collection and treatment to determine whether wastewater treatment needs
could be met in a more economical way.
ENVIRONMENT
Soils. The Soil Conservation Service (SCS) has not completed a
soil survey for the entire Study Area. Specific shoreline data indicate
that soils set back from Otter Tail Lake are generally suitable for
septic tanks, spray irrigation and rapid infiltration based on SCS
criteria. Soils along the shoreline of Otter Tail Lake are largely
limited in suitability for on-site disposal by a high groundwater table,
and high flow rates.
Surface Water Resources. Surface water resources of Otter Tail
Lake, Lake Blanche, Deer Lake, Round Lake, Long Lake and Walker Lake are
an issue in this EIS. Because of its size and attractiveness as a
resort Otter Tail Lake is the center of concern. Otter Tail Lake occu-
pies 14,746 acres within a drainage basin 49 times the area of the lake.
The Otter Tail River is the major tributary source. In addition to
inflow from the River, Otter Tail Lake receives flow from Lake Blanche,
Walker Lake and Long Lake. The hydrology of the lakes directly affects
the water quality. Non-point sources contribute a large percentage of
the nutrient load to all lakes except Long Lake and Round Lake. The
alkaline nature of the lakes may have a significant effect on reducing
the availability of nutrients for plant uptake. Otter Tail Lake is
apparently mesotrophic and unlikely to change for any alternative. The
exact trophic status of the smaller surrounding lake cannot be deter-
mined because of the lack of long-term data.
Groundwater Resources. Groundwater is the major source of water
for domestic use in the Study Area. Water supply is plentiful although
it is naturally high in iron and manganese. High nitrate concentrations
have been observed in 6 out of 40 wells sampled recently. Nitrate
concentrations were often reduced to acceptable levels by repairing a
malfunctioning on-site system(s).
Existing Population and Land Use. Approximately 83% of the Service
Area population consists of seasonal and vacation residents who reside
in unsewered areas along the shorelines of Otter Tail Lake and the
smaller surrounding lakes. Development has occurred in a single tier
pattern throughout most of the Proposed Service Area. The permanent
population is characterized by a relatively low income that is below the
average income for Minnesota. However, the low income levels can be
explained by the fact that about 40% of the permanent Study Area popu-
lations is over 55 and many are retired and on a fixed income. Also
agriculture and tourism, both low-wage employment, are the principle
industries.
ADDITIONAL STUDIES
Because there were insufficient data to determine wastewater treat-
ment needs, 2 additional studies were performed for this EIS.
323 D4 iv
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1) An aerial photographic survey was performed by the Environ-
mental Photographic Interpretation Center (EPIC) during the
summer of 1978. Few surface malfunctions resulting from
on-site sewage disposal systems were observed. Suspected beds
of aquatic vegetation were observed on infrared photographs
but were not verified. On Otter Tail Lake, dense vegetation
was observed between Walker Lake and Long Lake and along the
south shore adjacent to wetlands.
2) A study of septic leachate discharges into Otter Tail Lake and
the small surrounding lakes was performed during April 1979.
A one-to-one relationship was observed between the number of
permanent residences and the number of septic leachate plumes
along most shoreline segments. Few if any plumes were
detected in Walker Lake, Long Lake and Lake Blanche; this was
attributed to the observation that high groundwater flow
carries the septic tank leachate to Otter Tail Lake rather
than to the smaller lakes.
Other additional studies, including a partial sanitary survey and a
summer leachate study are now in progress.
ALTERNATIVES
Based upon the high cost of conventional technology and the ques-
tions concerning the eligibility of new sewers for funding, 6 new
alternatives were evaluated in this ETS along with the Facility Plan
Proposed Action. These alternatives considered individual and multi-
family septic systems (cluster systems), black water separation, and
water conservation as well as different configurations for land applica-
tion and pressure sewers than were considered in the Facility Plan. The
Facilities Plan Proposed Action would have a present worth cost,
including 20 year of operation arid maintenance of $10.36 million.
EIS Alternative 1. A Jand application system serving the south
shore of Otter Tail Lake, between Lake Blanche and Otter Tail Lake.
Stream discharge to Otter Tail Lake would be required if rapid infil-
tration were selected, but no stream discharge would be required with
spray irrigation. Cluster systems for areas with rapid groundwater flow
rates, high groundwater levels and high population density. Repair and
rehabilitation of remaining on-site systems. The total, present worth
cost of this alternative, including 2U years of operation and mainte-
nance, is $9.30 million.
EIS Alternative 2. Two land application systems, one serving the
south shore between Lake Blanche and Otter Tail Lake, the other serving
the west/northwest shore of Otter Tail Lake. The remainder of the
Proposed Service Area would be served by on-site systems and cluster
systems suitable to local conditions. Total present worth costs of this
alternative, including 20 years of operation and maintenance, were
$10.20 million.
EIS Alternative 3. Same as EIS Alternative 2 except that the
centralized collection and treatment system for the west/northwest shore
323 D5 v
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is extended along the entire northeast shore. Total present worth costs
for this alternative, including 20 years of operation and maintenance,
were $10.5 million.
EIS Alternative 4. Entire Proposed Service Area would be served by
two land application systems. The Otter Tail shoreline from Pelican Bay
south to an area just beyond the north shore of Lake Blanche would be
conveyed to one land application site. The remaining segments would be
collected and conveyed to a site west of Otter Tail Lake. Total present
worth costs for this alternative, including 20 years of operation and
maintenance, were $11.335 million.
EIS Alternative 5. The entire Proposed Service Area would be
served by a prefabricated contact stabilization plant. The plant would
incorporate chemical addition for phosphorus removal and would discharge
to Otter Tail River. Total present worth costs for this alternative,
including 20 years of operation and maintenance is $10.245 million.
Limited Action. Repair and rehabilitation of existing on-site sys-
tems similar to that in EIS Alternative 1, with grey water/black water
separation for problem high groundwater flow areas. Total present worth
cost of this alternative, including 20 years operation and maintenance
is $7.14 million.
Implementation. Local jurisdications have the legal and financial
capability of implementing small waste flow districts, although the con-
cept of public management of septic systems has not had a final legal
determination in Minnesota, present sanitary codes have been interpreted
as authorizing such management by local governments. Similar districts
are already in operation.
IMPACTS OF ALTERNATIVES
Surface Waters. None of the alternatives is anticipated to have a
significant impact upon the present trophic status of Otter Tail Lake or
the smaller surrounding lakes -- Lake Blanche, Walter Lake and Deer
Lake. Continued reliance upon conventional septic tanks may result in
water quality degradation in Round Lake and Long Lake as development
increases along the shorelines.
Impacts of septic tanks on lakeshore eutrophication which results
in algae growth is the subject of further study in July and August of
1979.
Groundwater. No significant primary or secondary impacts on
groundwater quantity are anticipated with any of the EIS Alternatives.
Conclusions with respect to long term impacts on groundwater
quality are as follows:
o Bacterial contamination is anticipated to be insignificant for
all alternatives.
323 D6 vi
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o Continued reliance on on-site systems in problem areas may
result in leaching of phosphorus to surface water in con-
centration sufficient to sustain algae growth.
o Centralized collection systems would eliminated septic tanks
as a potential source for groundwater nitrate contamination in
areas with high housing density and high groundwater table.
o Cluster systems would minimize the potential for contamination
of groundwater supplies.
o Land application of wastewater is not anticipated to result in
groundwater contamination of nitrates since design measures
can be taken to prevent this.
Environmentally Sensitive Areas. Wetlands located between Lake
Blanche and Otter Tail Lake are likely to be impacted by any of the EIS
Alternatives, except Limited Action.
Population and Land Use Impact. A 0% to 9% increase in population
above the baseline projections is anticipated for the EIS Alternatives;
the increase is directly related to the extent of sewering. The land
use pattern would be only slightly modified by any of the EIS Alterna-
tives. Density of shoreline development would increase with extent of
sewering. Second tier development is unlikely with any of the alterna-
tives.
Economic Impacts. Annual user charges are estimated to range from
$165 to $350. Approximately 60 to 70°/0 of the households would be able
to afford Limited Action or Alternatives 1. A financial burden would be
placed on 30 to 40% of the area's households and displacement pressure
would range from 15% to 30%. Burden and displacement pressures for the
centralized alternatives are about double this.
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TABLE OF CONTENTS
Summary i
List of Tables xvi
List of Figures xvii
Abbreviations xviii
I. INTRODUCTION, BACKGROUND AND ISSUES 1
A. Project History and Description 1
1. Background 1
2. Location 1
3. History of the Construction Grant Application 4
4. The Otter Tail Lake Area Facility Plan 5
a. Existing Wastewater Treatment Facilities 5
b. Existing Problems with Water Quality and
Wastewater Treatment Facilities
c. Proposed Solutions: Alternative Addressed
in the Facility Plan 6
d. The Facility Plan Proposed Action 9
B. Issues of this EIS 9
1. Cost Effectiveness 9
2. Impacts on Water Quality 9
3. Economic Impact 10
4. Induced Growth and Secondary Impacts 10
C. National Perspective on the Rural Sewering Problem 10
1. Socioeconomics 10
2. Secondary Impacts 13
3. The Need for Management of Decentralized
Alternative Systems 13
D. Purpose and Approach of the EIS and Criteria for
Evaluation of Alternatives 14
1. Purpose 14
2. Approach 15
a. Review of Available Data 15
b. Segment Analysis 15
c. Review of Wastewater Design Flows 15
d. Development of Alternatives 16
e. Estimation of Costs for Alternatives 16
f. Evaluation of the Alternatives 16
g. Needs Documentation 16
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3. Major Criteria for Evaluation of: Alternatives
a. Cost
b. Significant Environmental and Socioeconotnic Impacts
c. Reliability
d. Flexibility
II. ENVIRONMENTAL SETTING 19
A. Physical Setting 19
1. Physiography 19
2. Geology 19
a. Bedrock Geology 19
b. Surficial Geology 22
3. Soils 22
a. Overview 22
b. Sol] Series in the Study Area 22
c. Soil Suitability of an On-Site Disposal System 29
d. Soil Suitability for Land Application 31
e. Prime Agricultural Lands 31
4. Atmosphere
31
a. Climate 31
b. Odors 32
c. Noise 32
d. Air Quality 32
B. Water Resources ^3
1. Water Quality Management 33
a. Clean Water Act 33
b. Federal Agency Responsibilities for Study Area Waters 34
c. State Responsibilities in the Otter Tail Lake
Study Area 35
d. Local Responsibilities for Water Quality Management 36
2. Groundwater Use 36
3. Groundwater Hydrology ^
4. Groundwater Quality
5. Surface Water Hydrology ^3
a. Size of Drainage Basins
b. Tributary Flow 43
c. Lake Hydraulic Retention Time *°
d. Precipitation ^"
e. Hydraulic Budget 46
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Page
6. Surface Water Use and Classification 48
7. Surface Water Quality 48
a. Streams 48
b. Lakes 49
8. Flood Hazard Areas 57
C. Existing Systems 57
1. Summary of Data 58
a. EPIC Survey 58
b. Investigation of Septic Leachate Discharges,
Otter Tail Lake, Minnesota 58
c. Construction Grant Sanitary Survey for Otter
Tail Lake 62
2. Shoreland Management Ordinance 62
3. Problems Caused by Existing Systems 65
D. Biotic Resources 68
1. Aquatic Biology 68
a. Fisheries 68
b. Aquatic Vegetation 69
c. Waterfowl 70
2. Wetlands 70
a. Overview 70
b. Study Area 70
3. Terrestrial Biology 72
a. Forest Lands 72
b. Wildlife 73
4. Threatened or Endangered Species 73
E. Population and Socioeconoraics 74
1. Existing Population 74
2. Population Projections 74
3. Characteristics of the Population 77
a. Income 77
b. Employment 81
c. Financial Characteristics 81
4. Housing Characteristics 84
5. Land Use 84
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a. Existing Land Use 84
b. Future Land Use/Growth Management 87
c. Recreation 89
d. Transportation 89
6. Cultural Resources 92
a. Archaeological Resources 92
b. Historical Resources 94
III. DEVELOPMENT OF ALTERNATIVES 95
A. Introduction 95
1. General Approach 95
2. Comparability of Alternatives: Design Population 97
3. Comparability of Alternatives: Flow and Waste Load
Projections 97
B. Components and Options 99
1. Flow and Water Reduction 99
a. Residential Flow Reduction Devices 99
b. Minnesota Ban on Phosphorus 102
2. Collection 103
3. Wastewater Treatment 106
a. Centralized Treatment 106
b. Land Disposal 107
c. Decentralized Treatment and Disposal 110
4. Effluent Disposal 113
a. Reuse 114
b. Discharge to Surface Waters 114
c. Land Application 115
5. Sludge Handling and Disposal 115
C. Reliability 115
1. Sewers 115
2. Centralized Treatment 117
3. On-Site Treatment 117
4. Cluster Systems 118
D. Flexibility 118
1. Transmission and Conveyance 118
2. On-Site Septic Systems 119
XI
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3. Conventional Wastewater Treatment
4. Contact Stabilization
5. Land Application
E. Implementation 121
1. Centralized Districts 121
a. Authority 121
b. Managing Agency 122
c. Financing 122
d. User Charges 122
2. Small Waste Flow Districts 123
a. Authority 123
b. Management 124
c. Financing 127
d. User Charges 127
IV. ALTERNATIVES
A. Introduction 129
1. Approach 129
2. Alternatives 129
a. No Action 132
b. Facility Plan Proposed Action 132
c. Limited Action Alternative 136
d. EIS Alternative 1 136
e, EIS Alternative 2 139
f. EIS Alternative 3 141
g. EIS Alternative 4 141
h. EIS Alternative 5 144
3. Flexibility of Alternatives 144
a. No Action 144
b. Facility Plan Proposed Action 144
c. Limited Action Alternative 144
d. EIS Alternative 1 144
e. EIS Alternatives 2, 3 and 4 146
f. EIS Alternative 5 146
V. IMPACT EVALUATION 147
A. Impacts on Surface Water Quality 147
1. Primary Impacts 147
a. Analysis of Eutrophication Potential 147
b. Bacterial Contamination 151
c. Non-Point Source Loads 151
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2. Secondary Impacts 151
3. Mitigative Measures 152
B. Impacts on Groundwater 153
1. Groundwater Quantity Impacts 153
2. Groundwater Quality Impacts 153
C. Impacts on Population and Land Use 156
1. Impacts on Population 158
2. Land Use 158
a. Development Potential 158
b. Residential Land Use Patterns 159
c. Industrial, Service and Resort Land Use Impacts 159
3. Changes in Community Composition and Character 160
D. Encroachment on Environmentally Sensitive Areas 160
1. Wetlands 160
a. Primary Impacts 160
b. Secondary Impacts 161
c. Mitigative Measures 161
2. Flood Plains 161
a. Primary Impacts 161
b. Secondary Impacts 161
c. Mitigative Measures 162
3. Steep Slopes 162
a. Primary Impacts 162
b. Secondary Impacts 162
c. Mitigative Measures 162
4. Prime Agricultural Land 162
5. Forests and Woodlands 163
a. Primary Impacts 163
b. Secondary Impacts 163
6 Archaeological and Historical Sites 163
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Page
E. Economic Impacts 163
1. Introduction 163
2. User Charges 163
a. Eligibility 164
b. Calculation of User Charges 165
3. Local Cost Burden 165
a. Significant Financial Burden 165
b. Displacement Pressure 166
c. Conversion Pressure 166
4. Mitigative Measures 166
F. Narrative Impact Matrix 169
VI. CONCLUSIONS AND RECOMMENDATIONS 177
A. Introduction 177
B. Summary of Evaluation 177
C. Conclusions 181
D. Draft EIS Recommendation 183
E. Implementation 184
1. Completion of Step 1 (Facilities Planning) Requirements
for the Small Waste Flows District 184
2. Scope of Step II for the Small Waste Flows District 184
3. Compliance with State and Local Standards in the
Small Waste Flows District 185
4. Ownership of On-Site Systems Serving Seasonal Residences 185
VII. THE RELATIONSHIP BETWEEN SHORT-TERM USE
AND LONG-TERM PRODUCTIVITY 187
A. Short-Term Use of the Study Area 187
B. Impact Upon Long-Term Productivity 187
1. Commitment of Non-Renewable Resources 187
2. Limitations on the Beneficial Use of the Environment 187
VIII. IRREVERSIBLE AND IRRETRIEVABLE
COMMITMENT OF RESOURCES 189
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Page
IX. PROBABLE ADVERSE IMPACTS WHICH CANNOT BE AVOIDED 191
Glossary 193
Bibliography 207
xv
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TABLES
1-1 Projected 1996 and Full Development Wastewater Flows 7
1-2 Present Worth of Alternatives Addressed in the Otter
Tail Lake Facility Plan 8
II-l Description of Soil Series with Basic Characteristics 27
II-2 Groundwater Quality Data for Otter Tail Lake Area 41
II-3 Physical Characteristics of Study Area Lakes 45
II-4 Water Budget for Otter Tail Lake 47
II-5 Selected Water Quality Parameters 50
II-6 Phosphorus and Nitrogen Budgets for Otter Tail Lake,
Deer Lake, Walker Lake, Round Lake, Long Lake and
Lake Blanche 51
II-7 The Relationship Between Number of Species of Fishes,
Area, and Depth for the Six Lakes in the Study Area 67
II-8 Permanent Population Trends of the Socioeconomic Study
Area for the Period 1940-1975 75
II-9 Existing Permanent and Seasonal Population for the
Service Area (1976) 76
11-10 Permanent and Seasonal Population of the Otter Tail
Lakes Proposed Service Area (2000) 78
11-11 Mean and Median Family Income 1970, Per Capita Income
1969 and 1976 79
11-12 Income Characteristics of Families, 1970 80
11-13 Percentage Employment by Major Industry, 1970 82
11-14 Financial Characteristics of the Local Governments in
the Otter Tail Lake Study Area 83
11-15 Existing Dwelling Units in the Otter Tail Proposed
Service Area 85
11-16 Minimum Shoreland Ordinance Standards 88
11-17 Public Access to Lakes in the Otter Tail Study Area 90
11-18 Private Campgrounds Located in the Otter Tail Lake
Study Area 91
III-l Design Flows for EIS Alternatives 98
III-2 Estimated Savings with Flow Reduction Devices 101
III-3 Small Waste Flow Management Functions by Operational
Component and by Basic and Supplemental Usage 125
IV-1 Alternatives - Summary of Major Components 130
IV-2 Design Population and Flow (2000) for Shoreline Areas 131
IV-3 Cost-effectiveness of Alternatives 134
V-l Phosphorus Loads by Alternative and Per Cent Change
Compared to Existing Conditions 148
V-2 Comparison of Population and Land Use Impacts Associated
with Major System Alternatives 157
V-3 Annual User Charges 164
V-4 Financial Burden and Displacement Pressure 167
VI-1 Alternative Selection Matrix 178
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FIGURES
1-1 Location of the Otter Tail Study Area 2
1-2 Proposed Sewer Service Area, Otter Tail Study Area 3
1-3 Monthly Costs of Gravity Sewers 12
II-l Topography of the Otter Tail Study Area 20
II-2 Geological Cross-Section Showing the Extent of Major
Aquifer Systems of the Otter Tail Study Area 21
II-3 Soil Landscapes in the Otter Tail Study Area 23
II-4 Soil Limitations for On-Site Systems for Selected
Sites in the Otter Tail Study Area (Sites 1 and 2) 24
II-5 Soil Limitations for On-Site Systems for Selected
Sites in the Otter Tail Study Area (Sites 3 and 4) 25
II-6 Soil Limitations for On-Site Systems for Selected
Sites in the Otter Tail Study Area (Sites 5 and 6) 26
II-7 Proposed Location of Land Application Sites Within
the Otter Tail Study Area 30
II-8 Location of Irrigation Fields in the Otter Tail Study
Area 37
II-9 Areal Extent of Outwash Aquifer 38
11-10 Groundwater Flow Patterns Surrounding Otter Tail Lake 40
11-11 Location of Well Water Samples 42
11-12 Otter Tail River Watershed and USGS Sampling Stations 44
11-13 Comparison of Phosphorus Loadings by Source Contribution
for Lakes in Otter Tail Study Area 52
11-14 Graphic Conditions for Otter Tail Lake and Round Lake 54
11-15 Flood Hazard Areas in the Otter Tail Study Area 56
11-16 Suspected Beds of Aquatic Vegetation and Locations of
Surface Malfunctions from On-Site Systems 59
11-17 Location of Erupting and Stream Source Plumes 60
11-18 Distribution of Lot Sizes and Percentage of Lots With
High Groundwater Levels 64
11-19 Wetlands of the Otter Tail Study Area 71
11-20 Existing Land Use in the Otter Tail Study Area 86
11-21 Archaeological and Historical Sites in the Otter Tail
Study Area 93
III-l Typical Pump Installation for Pressure Sewer 105
III-2 Prefabricated Contact Stabilization Plant 108
III-3 Land Application Spray Irrigation 109
III-4 Recovery of Renovated Water by Wells 110
III-5 Land Application Rapid Infiltration 110
IV-1 Segments Map 133
IV-2 Facility Plan Proposed Action 135
IV-3 Limited Action Alternative 137
IV-4 EIS Alternative 1 138
IV-5 EIS Alternative 2 140
IV-6 EIS Alternative 3 142
IV-7 EIS Alternative 4 143
IV-8 EIS Alternative 5 145
V-l Trophic Status of Otter Tail and Round Lakes Under
Various Alternatives 150
xvii
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SYMBOLS AND ABBREVIATIONS
P
y
v
a
An asterisk following a word indicates that the term is
defined in the Glossary at the end of this report. Used
at the first appearance of the term in this EIS.
less than
greater than
Rho
Mu, micro
Nu
Sigma
TECHNICAL ABBREVIATIONS
AWT
BOD
DO
ft2
fps
g/m /yr
GP
gpcd
gpm
I/I
kg/yr
kg/cap/yr
kg/mile
lb /cap /day
mgd
mg/1
ml
msl
MPN
N
NO -N
NFS
advanced wastewater treatment
biochemical oxygen demand
dissolved oxygen
square foot
feet per second
grams per square meter per year
grinder pump
gallons per capita per day
gallons per minute
infiltration/inflow
kilograms per year
kilograms per capita per year
kilograms per mile
pounds per capita per day
million gallons per day
milligrams per litre
millilitre
mean sea levelimplies above msl unless otherwise indicated
most probable number
nitrogen
ammonia nitrogen
nitrate nitrogen
non-point source
xviii
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O&M
P
pH
?°4
ppm
psi
RBC
SS
STEP
STP
ST/SAS
TKN
TP-P
Ug/1
EPAECO
operation and maintenance
phosphorus, or "as phosphorus"
measure of acidity or basicity; <7 is acidic; >7 is basic
phosphate
parts per million
pounds per square inch
rotating biological contactor
suspended solids
septic tank effluent pumping
sewage treatment plant
septic tank/soil absorption system
total Kjeldahl nitrogen
total phosphorus as phosphorus
micrograms per liter
name of a mathematical model
DNR
EIS
EPA
EPIC
FWS
HUD
NOAA
NES
NPDES
SCS
STORE!
USDA
USGS
NON-TECHNICAL ABBREVIATIONS
Minnesota Department of Natural Resources
Environmental Impact Statement
United States Environmental Protection Agency
Environmental Photographic Interpretation Center (of EPA)
Fish and Wildlife Service, United States Department of
the Interior
United States Department of Housing and Urban Development
National Oceanic and Atmospheric Administration, United
States Department of Commerce
National Eutrophication Survey
National Pollutant Discharge Elimination System
Soil Conservation Service, United States Department of
Agriculture
STOrage and RETrieval (data base system of EPA)
United States Department of Agriculture
United States Geological Survey, Department of the Interior
xix
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CHAPTER I
INTRODUCTION, BACKGROUND AND ISSUES
A. PROJECT HISTORY AND DESCRIPTION
1. AUTHORITY
Partial Federal aid in funding of municipal wastewater facilities
is authorized by Section 201 of the Federal Water Pollution Control Act
Amendments of 1972 (FWPCA), Public Law 92-500. This funding is subject
to the provisions of the National Environmental Policy Act of 1969
(NEPA), Public Law 91-190. Section 102(2)(C) of NEPA requires the
preparation of an environmental impact statement (EIS) on major Federal
actions significantly affecting the quality of the human environment.
Guidance for preparation of this EIS is provided by the Council on
Environmental Quality's "Preparation of Environmental Impact Statements:
Guidelines" August 1, 1973 (40 CFR Chapter V, Part 1500) and the Envi-
ronmental Protection Agency's "Manual for Preparation of Environmental
Impact Statements for Wastewater Treatment Works, Facilities Plans, and
208 Areawide Waste Treatment Management Plans" July 1974. Individual
provisions of revised Council on Environmental Quality guidelines issued
November 29, 1978 have been followed where practicable.
2. LOCATION
The subject of this Environmental Impact Statement (EIS) is the
Federal funding of proposed wastewater collection and treatment facil-
ities requested for the Otter Tail Lake area of Otter Tail County,
Minnesota. The Otter Tail Lake area Facility Plan recommended the
construction of the facilities described later in this chapter.
The Facility Planning (or the EIS Study Area) area includes the
four townships of Girard, Amor, Otter Tail and Everts. Together these
four townships comprise 144 square miles of farmland, lakes, residential
shoreline development and woodland in tlie west-central part of the State
of Minnesota. Figure 1-1 shows the Study Area within the State of
Minnesota. The residential areas to be served by the new wastewater
facilities, the Proposed Service Area, covers only a small part of these
four townships and includes the unincorporated village of Ottertail and
the developed shoreline areas of Otter Tail Lake, Lake Blanche (north
shore), Walker Lake (south shore) , Long Lake (south shore) Round Lake
and Deer Lake. Figure 1-2 shows the boundaries of the Proposed Service
Area.
The combined year-round population of the Proposed Service Area is
estimated to be 1,094, increasing to about 6,344 in the vacation season.
The projected (year 2000) population is 1,805 permanent residents and
7,555 total residents.
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Pelican >
Rapids
OTTER TAIL COUNTY
Fergus
Falls,
Otlertail
Parkers
Prairie
FICURF, I-] LOCATION OF THE OTTKR 'I'M L STUDY ARFA
2
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FIGURE 1-2 PROPOSED SEWER SERVICE AREA, OTTER TAIL STUDY AREA
LEGEND
L_lJ
PROPOSED SEWER SERVICE AREA
MILES
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3. HISTORY OF THE CONSTRUCTION GRANT APPLICATION
Water quality problems and wastewater management needs of the Study
Area have for several years been a concern of both area citizens and
governmental agencies. The following chronology lists actions taken
before and during the preparation of this Environmental Impact State-
ment.
August 1969
February 1969-
March 1976
January 1974
June 1975
July 1975
August 1975
August 28, 1975
November 10, 1975
January 26, 1976
March 10, 1976
June 1976
"Report on the Otter Tail River System above Fergus
Falls," prepared by the Minnesota Pollution Control
Agency, Division of Water Quality.
Water quality samples taken by the City of Fergus
Falls at the request of the Otter Tail Lake Property
Owners Association to measure total coliform
bacteria.
"Load Allocation Study, Otter Tail River Segment,"
prepared for the Minnesota Pollution Control Agency.
Notification of intent to apply for Step 1 Facili-
ties Planning Grant received by West Central
Regional Development Commission from Otter Tail
County.
Final review by the West Central Regional Develop-
ment Commission in regard to above notifications.
Final review by the Minnesota State Planning Agency
of proposal to apply for Step 1 Grant.
Minnesota Pollution Control Agency (MPCA) receives
Step 1 Grant application form Otter Tail County.
Step 1 Grant offer verified by the Minnesota Pollu-
tion Control Agency and forwarded to Region V of US
Environmental Protection Agency (EPA) Region V.
EPA Region V makes Step 1 Grant offer.
Public meeting on development of a sewage facilities
plan for the Otter Tail Lake area.
Ulteig Engineers complete engineering study and
environmental assessment of wastewater management
alternatives, "Facility Plan, Otter Tail Lake Area,
Otter Tail County, Minnesota."
June 26, 1976
Public hearing on the proposed Facility Plan, Otter
Tail Lake Area, Otter Tail County, Minnesota.
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July 12, 1976
July 1976
July 20, 1976
January 1977
March 18, 1977
June 1977
July 1977
October 1977
Otter Tail County Board of Commissioners approves
Otter Tail Lake Facility Plan.
The Otter Tail Lake Property Owners Association
petitions the County to establish a sewer district
in accordance with Minnesota Statutes, Chapter 116A.
Minnesota Pollution Control Agency receives the
Facility Plan.
Otter Tail County applies for additional Grant for
Needs Documentation.
EPA Region V approves additional grant for Needs
Documentation.
MPCA requests EPA to consider preparing an Environ-
mental Impact Statement.
Declaration of intent to prepare an EIS by EPA
Region V.
WAPORA, Inc., begins work on the EIS for the Otter
Tail Lake area.
August 1978 EIS public information meeting.
4. THE OTTER TAIL LAKE AREA FACILITY PLAN
In June 1976 the Otter Tail Lake Facility Plan was completed and
subsequently submitted to EPA Region V by Otter Tail County acting as
the applicant for funding under the EPA Construction Grants Program.
The Plan, proposing construction of new wastewater collection and
treatment facilities, was developed for the Otter Tail County Board of
Commissioners by Ulteig Engineers, Inc., of Fargo, North Dakota.
Centralized collection and treatment by waste stabilization lagoons
was selected as the Facility Plan Proposed Action because it proved the
most cost-effective of the two final alternatives considered.
a. Existing Wastewater Treatment Facilities
The entire Proposed Service Area including the unincorporated City
of Otter Tail, the developed shores of Otter Tail Lake and the smaller
surrounding lakes (Walker, Long, Blanche, Round and Deer) are served by
on-site systems. A thorough investigation of existing on-site systems
will not be completed until late August 1979. However, it is known that
the types of on-site systems include septic tank-soil absorption systems
(ST/SAS), holding tanks, cesspools and leaching pits, many not meeting
the minimum requirements of the County's Shoreland Management Ordinance.
-------
b. Existing Problems With Water Quality and Wastewater
Treatment Facilities
As a preliminary step in the development of wastewater management
alternatives, the Facility Plan cites the following problems:
Highly permeable sandy soil, small lot sizes and a seasonally
high water table may allow inadequately treated wastewater to
reach surface water and groundwater.
At least three times in the past, total coliform counts at the
outlet from Otter Tail Lake have been too numerous to count.
Monthly coliform counts at this location indicated a jump from
zero colonies per 100 ml. in the winter to summer high of
400-500 colonies per 100 ml.
High nitrate concentrations have been found locally in the
groundwater.
« Many septic tanks and their drainfields are totally submerged
in groundwater.
« Many older on-site systems violate the Otter Tail County
Shoreland Management Ordinance for elevation above ground-
water, setback from lakes or absorption areas.
t Sanitary sewage should be collected by a sewer system en-
circling Otter Tail Lake and serving Lake Blanche (north
shore), Walker Lake (south shore), Long Lake (south shore),
Round Lake and Deer Lake.
c. Proposed Solutions: Alternatives Addressed in the
Facility Plan
The Facility Plan developed four alternative wastewater management
plans to meet effluent requirements and alleviate problems of the exist-
ing treatment systems. Selection of the Proposed Action was based upon
a comparison of costs, environmental impacts, reliability, and imple-
mentability.
The facility planners developed two sets of design flows: one based
upon population projections for 1996; the other upon the total popula-
tion resulting if all available land were developed. Wastewater flows
of 65 gallons per capita per day (gpcd) included infiltration/inflow*
for both winter and summer. This represents an average yearly flow of
254,367 gallons per day and a peak flow of 563,420 gal/day. Table 1-1
presents the projected wastewater flows for 1976, 1996 and full
development.
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Table 1-1
PROJECTED 1996 AND FULL DEVELOPMENT WASTEWATER
FLOWS, OTTER TAIL LAKE STUDY, OTTER TAIL
LAKE AREA FACILITY PLAN
Winter Population
Max. Summer Population
Winter Flow
Summer Flow
1976 (Present)
1,114
6,288
72,410 gal/day
408,720 gal/day
1996
1,506
8,500
97,890
gal/day
552,500
gal/day
Full Development
1,536
8,668
99,840
gal/day
563,840
gal/day
The Facility Plan considered the following elements to develop its
alternatives:
Collection systems,
Wastewater treatment and disposal, and
Discharge standard of 1 mg/1 phosphorus for Otter Tail Lake.
The Facility Plan considered the advantages and disadvantages of
gravity and low pressure collector sewers, concluding a combination of
the two would best serve the Proposed Service Area. It did not consider
sludge disposal options or flow reduction measures in the Facility Plan.
The four wastewater management alternatives developed by the
Facility Plan were:
Alternative No 1. Septic tank-soil absorption systems in conjunc-
tion with holding tanks.
Alternative No. 2. A central collection system with wastewater
treatment at an activated sludge treatment plant with phosphorus
removal.
Alternative No. 3. A central collection system with treatment by
stabilization ponds and a single land application site. The facility
would be located in Amor Township (Section 32) about one-third mile from
Otter Tail Lake.
Alternative No. 4. A central collection system with multiple
stabilization ponds and two land application sites.
Table 1-2 shows the Facilty Plan estimated project construction
costs, operation and maintenance costs, salvage values and the total
present worth for each of the four alternatives. An interest rate of
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TABLE 1-2
PRESENT WORTH OF ALTERNATIVES ADDRESSED IN THE OTTER TAIL FACILITY PLAN
PRESENT WORTH
Capital Cost
Collection
Treatment
Pumping
Operation &
Maintenance
Collection
Treatment
Design & Plans
Collection
Treatment
Hook-up
Collection
Salvage Value
Alternative
No. 1
$2,110,683.48
A,181,383.11
80,5^1.22
Alternative
No. 2
Alternative
No. 3
Alternative
No. 4
$3,577,949.72 $3,577,949.72 $3,570,374.20
481,000.00 657,390.33 720,752.50
355,869.10
533.638.00
355,869.10
193,018.00
355,869.10
193,018,00
286,235.98 286,235.98 286,235.98
38,480.00 34,442.32 34,442.32
600,461.04 600,461.04 600,461.04
-none- -none- -none- -none-
TOTAL
$6,372,607.81 $5,873,633.84 $5,705,366.49 $5,761,153.14
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6-1/8% and a 20-year planning period were used to develop the costs in
the table.
d. The Facility Plan Proposed Action
Alternative No. 3 was selected as the most reasonable method of
treatment and disposal based on water quality objectives, reliability,
operability and implementability. The alternatives included a basic
gravity sewer collection system, augmented by grinder pumps and low
pressure sewers. The Facility Plan recommended construction of treat-
ment capacity in three phases from 1977 through 1982. The effluent
would be treated in stabilization ponds and applied to the land by spray
irrigation. The proposed site was located in Section 32 of Amor Town-
ship on the west shore of Otter Tail Lake.
B. ISSUES OF THIS EIS
The Environmental Protection Agency's review of the Facility Plan
Proposed Action identified the following issues as warranting the prep-
aration of this EIS.
1. COST EFFECTIVENESS
The total present worth for the Facility Plan Proposed Action was
estimated as $5.7 million. This amounts to an investment of $700 per
person and $2,415 per existing dwelling unit within the Proposed Service
Area.
The collection system recommended in the Facility Plan was esti-
mated to cost $4.8 million -- 84% of the total cost of the Proposed
Action. The impact of the cost of the collection system on the local
community may be greater than the cost for other components of the
project since MPCA does not usually assign fundable priorities to
collection systems. Although the use of ST/SAS and holding tanks was
considered as an alternative by the Facility Plan Engineers, this
alternative was ruled out on the basis of reliability.
2. IMPACTS ON WATER QUALITY
The likely water quality impacts of the Facility Plan Proposed
Action and alternatives were not satisfactorily addressed in the
Plan. Of principal concern to the applicant were further eutrophication
and bacterial contamination of Otter Tail Lake and impacts on ground-
water quality. Although the Facility Plan presented indirect evidence
that there may be water quality problems, claims of a connection between
deteriorating water quality and inadequately functioning septic systems
have not been documented. In addition, claims of possible hazards to
public health were not fully substantiated. Therefore, it is not yet
clear that the proposed level of resource commitment would be necessary.
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3. ECONOMIC IMPACT
The estimated user charge for the Facility Plan Proposed Action was
$170 per year for each residence or residential equivalent in the new
sewer service area around Otter Tail Lake. This charge would amount to
1.4% of the permanent residents' average annual income. Otter Tail Lake
Proposed Sewer Service Area homeowners would pay an initial $970 for
stub fee* and connection charge to a gravity sewer. In addition, the
homeowner would pay for installation of a house sewer connecting his
household plumbing with the public sewer.
The effect of these sewerage costs could be to encourage seasonal
and fixed income residents to sell their properties or in some instances
to convert from seasonal use to permanent residency.
4. INDUCED GROWTH AND SECONDARY IMPACTS
Shoreline sewer availability could allow construction of dwelling
units at slightly higher densities than is currently feasible. However,
most of the shoreline is already developable without provisions for
centralized treatment. Undeveloped lots along the shoreline indicate
that there is some potential for increased development. Although second
tier land is available for development, this type is not likely to occur
to a significant extent during the planning period, while more desire-
able lakeshore lots are available throughout the region.
In particular, increased housing construction along shoreline areas
could accelerate soil erosion which, in turn, would increase nutrient
input to Otter Tail Lake and sewered areas of the smaller lakes.
C. NATIONAL PERSPECTIVE ON THE RURAL SEWERING PROBLEM
These EIS issues discussed above are not unique to the proposed
plan in the Otter Tail Lake Study Area. Similar concerns are raised by
the many wastewater projects for rural and developing communities
recently submitted to EPA for funding. The scope of the problem has
grown through several years of mounting controversy over the high costs
and possible impacts of providing conventional sewerage facilities to
small communities across the country.
1. SOCIOECONOMICS
To assess the cost burden that many proposed wastewater collection
projects would impose on small communities and the reasons for the high
costs, EPA studied over 250 facilities plans from 49 states for pending
projects for communities under 50,000 population (Dearth 1977). EPA
found that even with substantial State and Federal construction grants,
the costs of conventional sewering are sometimes prohibitive for
families in rural and semi-rural areas. This was particularly true for
those communities where the new facilities proposed would result in
annual user charges exceeding $200 per household.
10
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The Federal government has developed criteria to identify high-cost
wastewater facilities projects (The White House Rural Development
Initiatives 1978). Projects are considered to place a financial burden
on rural community users when annual user charges (debt service plus
operation and maintenance) would exceed:
1.5% of median household incomes less than $6,000;
2.0% of median household incomes between $6,000 and $10,000;
or
2.5% of median household incomes over $10,000.
Annual user charges exceeding these criteria would materially affect the
households' standard of living. Where these criteria are exceeded,
Federal agencies involved in funding wastewater facilities will work
with the community to achieve lower project costs through scope or
design changes. If the project's scope or design is not changed, the
agencies will work with the community until assured that it is aware of
the financial impacts of undertaking the high-cost project.
The collection system is chiefly responsible for the high costs of
conventional sewerage facilities for small communities. Typically, 80%
or more of the total capital cost for newly serviced rural areas is
spent for collection. Figure 1-3 indicates that the costs per residence
for gravity sewers increase exponentially as population density
decreases. Primary factors contributing to this cost/density relation-
ship were:
greater length of sewer pipe per dwelling in lower-density
areas;
more problems with grade, resulting in more lift stations or
excessively deep sewers;
regulations or criteria setting eight inches as the smallest
allowable sewer pipe diameter; and
inability of small communities to spread capital costs among
larger populations sewered previously.
Besides the comparatively high costs of sewers, facilities were
sometimes found to be overly expensive due to:
Oversophisticated design, with accompanying high chemical
usage, large energy requirements, and costly maintenance and
operator expense, when simpler methods would do.
Use of expensive construction materials such as non-locally
produced brick and block and terrazzo when a prefab steel and
concrete building would perform satisfactorily.
Abandonment of existing treatment works witnout economic
justification.
11
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Figure 1-3
40
5 30
1
10
* 6 9 10 12
Population 0«M4ty. p«fsom/aer*
Monthly Cost Of Gravity S*wars
14
Dearth, K.H. 1977. In proceedings of EPA national conference on
less costly wastewater treatment systems for small communities,
A-pril 12-14, 1977, Reston, VA..
12
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2. SECONDARY IMPACTS
Installation of centralized collection and treatment systems in
previously unsewered areas can dramatically effect on development and,
hence, the economy, demography and environment of rural communities.
These effects can be desirable, or they may substantially offset com-
munity objectives for water resource improvement, land use planning and
environmental protection.
In broad terms, a community's potential for recreational, resi-
dential, industrial, commercial or institutional development is deter-
mined by economic factors such as the availability of land, capital,
skilled manpower and natural resources. However, fulfillment of the
potential can be limited by the unavailability of facilities or services
called infrastructure elements, such as water supply, sewerage, electric
power distribution and transportation. If a missing infrastructure
element is supplied, development of one type or another may take place,
depending upon prevailing local economic factors. Such development is
considered to be "induced growth".
Conflicts between induced growth and other types of existing or
potential development are also termed secondary impacts, as are induced
growth's effects on existing water resources, land use, air quality,
cultural resources, aesthetic features and environmentally sensitive
areas.
Secondary impacts of new wastewater facilities may be highly desir-
able. For example, diversification of the local employment base may be
possible only when sufficient wastewater collection and treatment
capacity is provided for commercial or industrial development. On the
other hand, new commercial or industrial development may not be com-
patible with existing recreational or agricultural interests. Resi-
dential development accompanying expansion of the employment base may
take place on prime agricultural land, steep slopes or wetlands, or may
otherwise infringe on valued natural features.
3. THE NEED FOR MANAGEMENT OF DECENTRALIZED ALTERNATIVE
SYSTEMS
A possible alternative to expensive centralized sewer systems in
rural areas is a decentralized wastewater management system. Both
engineering and management are integral parts of such a system, and
"decentralized alternatives," as used in this EIS, incorporate both
engineering and management elements.
Briefly, the engineering element consists of the use of existing
and new on-site systems, rehabilitation or replacement of those systems
where necessary, and construction of small-scale off-site systems where
existing on-site systems are not acceptable.
The management element consists of continuing supervision of the
systems' installation, maintenance, rehabilitation and appropriate
monitoring of the systems' environmental impacts.
13
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While other factors like soil characteristics, groundwater
hydrology and lot configurations are very important, adequate management
may be critical to the success of decentralized alternatives in many
communities. Similarly, complete lack of adequate management undoubt-
edly contributed to past failures of many on-site wastewater facilities
and, therefore, the lack of trust in which they are held by local public
health officials and consulting engineers.
Historically, State and local health officials were not empowered
even to regulate installation of on-site systems until after World War
II. They usually acted in only an advisory capacity. As the conse-
quences of unregulated use of the septic tank-soil absorption systems
became apparent in the 1950s and 1960s, health officials were granted
new authority. Most health officials now have authority to permit and
inspect or deny new installations; they can require renovation or re-
placement of on-site systems. However, their role in the operation and
maintenance of on-site systems remains largely advisory. There is
seldom either a budget or the authority to inspect or monitor a system.
In the 1970's, the Congress recognized the need for continuing
supervision and monitoring of on-site systems in the 1977 Clean Water
Act amendment. Now, EPA regulations implementing the Act require that
before a construction grant for on-site systems may be made, the appli-
cant must meet a number of requirements and must:
Certify that it will be responsible for properly installing,
operating and maintaining the funded systems;
Establish a comprehensive program to regulate and inspect
on-site systems, including periodic testing of existing
potable water wells and, where numerous on-site systems
exists, more extensive monitoring of aquifers; and
Obtain assurance of unlimited access to each individual system
at all reasonable times for inspection, monitoring, construc-
tion, maintenance, operation, rehabilitation and replacement.
In some cases, municipal implementation of these requirements may
be hindered by lack of State enabling legislation for small waste flow
management districts and by lack of adequately trained manpower. The
municipality may have no control over the former and be at a disadvant-
age because of the latter. Other implementation factors, over which
municipalities should have control, are discussed in Section III.D of
this EIS.
D. PURPOSE AND APPROACH OF THE EIS AND CRITERIA FOR
EVALUATION OF ALTERNATIVES
1. PURPOSE
This EIS documents EPA's review and analysis of the
application for EPA Step II funding of the Facility Plan Proposed
Action. Based upon this review, the Agency will take one of several
actions:
14
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Approve the grant application, possibly with recommendations
for design changes and/or measures to mitigate impacts of the
Facility Plan Proposed Action;
With the applicant's and State's concurrence, approve Step II
funding for an alternative to the Facility Plan Proposed
Action, as presented in this EIS;
Return the application with recommendations for additional
Step I analysis; or
Reject the grant application.
The review and analysis focused on the issues identified in Section
I.B and was conducted with an awareness of the more general considera-
tions of rural sewering problems discussed in Section I.C. Major
emphasis has been placed on developing and evaluating alternative waste-
water management approaches to be compared with the Facility Plan
Proposed Action.
2. APPROACH
The review and analysis reported Ln this EIS included a series of
tasks, which were undertaken in approximately the following sequence:
a. Review of Available Data
Data presented in the Facility Plan and other sources were reviewed
for applicability in development and/or evaluation of the Plan Proposed
Action and of the new alternatives developed for the EIS (EIS Alterna-
tives). Sources of data are listed in this Bibliography.
b. Segment Analysis
As a basis for revised population projections and for development
of alternatives, the Proposed Service Area was partitioned into a number
of segments. The number of dwellings in each segment was counted from
aerial photographs. Information on occupancy rates and breakdown of
permanent and seasonal residents for each segment was provided by local
residents. Available information on soils, depth to groundwater, water
quality problems, environmentally sensitive areas and land use capabili-
ties was tabulated for each segment and the tabulations used to make
preliminary estimates of the need for off-site wastewater disposal.
c. Review of Wastewater Design Flows
Available population projections were revised on the basis of the
segment house counts. New EPA guidelines for estimating design waste-
water flows were then used to revise the year 2000 wastewater flow
projections.
15
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d. Development of Alternatives
First, technologies that might potentially reduce project costs or
minimize adverse impacts while still solving existing problems were
examined. Four categories of alternative technologies -- flow reduc-
tion, low-cost sewers, decentralization, and land application -- were
considered according to their functions in a wastewater management
system. Next, several specific areawide alternatives were developed,
combining the alternative technologies into complete wastewater man-
agement systems that would serve the Proposed Service Area. The
technologies and the alternatives are described in Chapter III. The
alternatives and their costs are presented in Chapter IV.
Steps were taken to insure comparability of design and costs
between the new areawide alternatives developed for the EIS and the
alternative recommended by the Facility Plan. These steps included some
minor reworking of the Facility Plan's alternative but maintained its
basic configuration. The term "Facility Plan Proposed Action" as used
in the remainder of this EIS identifies the modified Facility Plan
alternative, not the original proposed.
e. Estimation of Costs for Alternatives
To assure cost comparability among the Facility Plan Proposed
Action and EIS Alternatives, all alternatives were designed to serve a
fixed design year population. Total present worth and local user charge
estimates were based upon unit costs listed in a separate engineering
report (Arthur Beard Engineers, Inc. 1978). Also to assure comparabil-
ity, grinder pumps recommended in the Facility Plan were replaced with
effluent pumps which receive and pump septic tank effluent. Effluent
pumps were used to cost all alternatives.
f. Evaluation of the Alternatives
The new alternatives were developed with a knowledge of the local
environmental setting and with the understanding that they will be
evaluated under criteria from several disciplines. The general criteria
for evaluating both the Facility Plan Proposed Action and the EIS Alter-
natives are listed in Section I.D.3 below.
g. Needs Documentation
Although there is evidence that many on-site systems are improperly
located and designed, there is no documentation that existing on-site
systems are resulting in widespread public health or water quality
problems. Because determination of eligibility for Federal funding of a
substantial portion of the Facility Plan Proposed Action would be based
on the documentation of these impacts, the following supplemental
studies were completed or scheduled for completion by the end of summer,
1979:
an aerial survey of visible septic tank system malfunctions
using low-altitude color and infrared photography by EPA's
Environmental Photographic Interpretation Center;
16
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estimation of the existing Otter Tail Lake nutrient budget;
a groundwater hydrology study to determine groundwater flow
direction with respect to Otter Tail Lake;
a "Septic Snooper" survey to locate and sample septic tank
leachate plumes entering Service Area lakes from nearby
on-site systems. A resurvey using the "septic snooper" is
scheduled for late summer 1979;
an evaluation by the Soil Conservation Service of soil suit-
ability for on-site systems; and
a sanitary survey to determine the types of on-site systems
and the nature and extent of problems with these systems;
scheduled for completion by the end of the summer of 1979.
The results of these needs documentation studies were not available
for consideration in the initial development of alternatives. The
results of each study have required continuing modification of the
alternatives as initially designed and have been the basis for necessary
refinements in the determination of the eligibility of any new sewers
around Otter Tail Lake for Federal funding.
3. MAJOR CRITERIA FOR EVALUATION OF ALTERNATIVES
While the high cost of sewering rural communities is a primary
reason for examining alternative approaches to wastewater management,
cost is not the only criterion. Trade-offs between cost and other major
impacts will have to be made. The various criteria are defined below.
a. Cost
With some exceptions for innovative technologies, EPA construction
grant regulations allow funding of only the most cost-effective alterna-
tives. Cost-effectiveness has been measured here as the total present
worth of an alternative, including capital costs for facilities needed
now, capital costs for facilities required later in the 20-year planning
period, and operation and maintenance costs for all wastewater facili-
ties. Salvage value for facilities expected to be in service after 20
years has been deducted. Analyses of cost-effectiveness do not recog-
nize differences between public and private expenditures.
Municipalities or sanitary districts recover operation, maintenance
and local debt retirement costs through periodic sewage bills. The
local economic impact of new wastewater facilities will be felt largely
through associated residential user charges. Only publicly financed
costs were included in residential user- charges. Salvage value was not
factored into residential user charges.
No assumptions were made in this EIS about frontage fees or hook-up
charges by the municipalities. Therefore, the user charges reported for
17
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the EIS Alternatives are not directly comparable to those reported in
the Facility Plan, where each newly sewered residence would pay in
connection and stub fees.
Some homeowners may incur costs payable directly to contractors.
Installation of gravity house sewers on private land and renovation or
replacement of privately owned on-lot systems for seasonally occupied
dwellings are not eligible for Federal funding and are seldom financed
by municipalities. These private costs are identified for each altern-
ative.
b. Significant Environmental and Socioeconomic Impacts
The system selected for the Proposed Service Area would impact
environmental and socioeconomic resources within the Study Area.
Following a comprehensive review of possible impacts of the Facility
Plan Proposed Action and the EIS Alternatives, several types of impacts
warranted in-depth evaluation and discussion in this EIS. These impacts
are:
Surface Water Quality Impacts,
Groundwater Impacts,
o Environmentally Sensitive Areas, and
« Economic Impacts.
They are discussed in Chapter V.
c. Reliability
Reliability for the alternatives include both ability to remedy
existing water quality problems and prospects of protecting water
quality in the future. This first criterion was applied in the analysis
of surface and groundwater impacts of the alternatives presented in
Chapter V. That analysis assumed that the collection, treatment and
disposal units of each alternative would operate effectively as
designed. The second criterion recognizes that all structural, mechan-
ical and electrical facilities are subject to failure. Types of
possible failures and appropriate remedies and preventive measures were
reviewed for selected components of the alternatives.
d. Flexibility
Flexibility allows an alternative to accommodate increasing waste-
water flows from future development in the Proposed Service Area. To
demonstrate the relative levels of investment for different alterna-
tives, all were designed and costed to provide service for the same
population the design year population projected in Chapter II.
However, factors such as the amount of land developable using on-lot
systems or the ability to increase treatment plant capacity might
significantly effect future development in the Study Area. Chapter III
discusses the capability of the alternatives to accomodate increased
wastewater flows. Chapter V projects the effects of alternative flexi-
bility on population grcwth.
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CHAPTER II
ENVIRONMENTAL SETTING
A. PHYSICAL SETTING
1. PHYSIOGRAPHY
The retreat of the last continental glacier over 10,000 years ago
produced the Study Area's gently rolling landscape of lakes and glacial
outwash* areas. The features of the Study Area (see Figure II-l) have
been modified only slightly by post-glacial erosional* processes.
The land within the Study Area generally slopes westward toward the
Otter Tail River. Topographic elevations range from 1250 to 1400 feet
above mean sea level (msl). Highest elevations are found north of
Walker Lake and west of Lake Blanche. These smaller lakes, Walker, Long
and Blanche, are a few feet higher in elevation than Otter Tail Lake.
The lakeshore areas are low lying; the southwest shore of Otter Tail
Lake contains an extensive low-lying wetland. The area between the
Otter Tail River inlet on the northeast shore and Walker Lake is nearly
level with intermittent patches of small wetland areas (United States
Geological Survey (USGS) 1973).
Most Study Area slopes are less than 5%. Hilly areas between the
lakes approach, but rarely exceed, 12%. Steep slopes over 15%, con-
sidered sensitive to development because they are subject to severe
erosion during construction, are uncommon (see Figure II-l).
The Otter Tail River drains the Study Area, flowing west through
Otter Tail Lake and Deer Lake and eventually reaching the Red River of
the North. A small section along the eastern boundary of the Study Area
is within the Upper Mississippi River drainage basin.
2. GEOLOGY
a. Bedrock Geology
Bedrock below the Study Area is among the oldest rock known on
earth. The igneous* basalts, granites and gabbros underlying the Study
Area were formed between 2.6 and 2.7 billion years ago. Metamorphosed*
igneous and sedimentary* rocks of Pre-Cambrian* age may also lie beneath
the Study Area (Reeder 1972). Rock of Cretaceous* age, composed of
sandstone and shale with traces of limestone, clay, and lignite, covers
the Pre-Cambrian basement material at the northern edge of the Study
Area. A geologic cross-section illustrating the position of bedrock
material in relationship to the overlying glacial deposits is shown in
Figure II-2.
19
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FIGURE 1T.-1 TOPOCTIAPHY OF THE OTTER TAIL STUDY AREA
LEGEND
MILES
0 I 2
Source: USGS 1973
20
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LOCATION OF CROSS SKCTION WITHIN STUDY AREA
LEGEND
SAND AND GRAVEL (OUTWASH AQUIFER)
CLAY
UNDIFFERENTIATED GLACIAL DRIFT (LOWER AQUIFER)
PRECAMBRIAN CRYSTALLINE ROCKS
15OO
900
FEET
Source: Winter et.al. 1969
FEET
FIGURE II-2
GEOLOGICAL CROSS SECTION SHOWING THE EXTENT OF MAJOR AQUIFER
SYSTEMS OF THE OTTER TAIL STUDY AREA
21
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b. Surficial Geology
The Study Area was once subject to the depositional and erosional
processes of continental glaciation. The bedrock is covered by a layer
of undifferentiated glacial drift* approximately 200 feet thick laid
down by great ice sheets which transported rock debris, gravel, sand,
and clay. This ice sheet retreated and melted, depositing sand and
gravel particles. These stratified outwash* deposits cover the undif-
ferentiated drift at depths of 50 to 100 feet (Winter et al. 1969). The
outwash material is thick and permeable and is the principal source of
groundwater within the Otter Tail River watershed (see Section II.B.2).
Figure II-2 also shows a cross-section of surficial geology the Study
Area.
Many Minnesota lakes were also formed by glacial processes. After
the glacier retreated, ice blocks deposited by the glacier melted,
forming basins and pits, many later filling with water. A wide variety
of surface depressions was thus created, many them lakes like those
within the Study Area (Minnesota Planning Agency 1969).
3. SOILS
a. Overview
Information on soils in the Study Area comes from two sources. The
University of Minnesota Department of Soil Science published a Soil
Atlas of Otter Tail County (1969) containing information about the
major soil series found in the Study Area. Figure II-3 shows this
information.
The Soil Conservation Service of the US Department of Agriculture
(SCS) has compiled information on Study Area soils, but not published a
detailed soil survey. To obtain site-specific data for this EIS, SCS
surveyed specific key sites within the Proposed Service Area, shown in
Figures II-4 through II-6.
b. Soil Series in the Study Area
Study Area soils were originally deposited as layers of sand and
gravel (see Section II.A.2.b). According to the Soil Atlas, 90% of the
Study Area contains moderately excessive to excessively drained sandy
soils. SCS concurs that in general Study Area soils have rapid
permeability.
The detailed descriptions of soil series in the Otter Tail Lake
area presented in Table II-l are based on the SCS survey (by letter,
Jerry Neseth, SCS, October 1978) and the Soil Atlas (1969). The series
can be grouped by location within the Study Area as follows:
The eastern section contains rapidly permeable, excessively
drained, sandy loam soils underlain by coarse sand and gravel.
The Salida, Sioux, and Hubbard soil series are found through-
out this area (SCS 1974-1977).
22
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-*"^*»_-^^A^'iAAJ'^.* £ ^J^^J^^f^^j^j^J^j^^^^
"
FTCOJRK 11-1 SOI
LANDSCAPES IN THE OTTER TAIL STUDY AREA
SALIDA-STOUX-ffUBBARD
(Sandy over sandy,
well drained soils)
UNNAMED (Sandy over
sandy, poorly drain-
ed soils)
ESTERVILLE-ARVILLA
(Loamy over sandy,
well drained soils)
MARQUETTE-LENG BY
(Deep silcy or Loamy,
well drained soils)
PEAT (Organic soils)
NEBISH-MARQUETTE-TODD
(Sandy over sandy,
well drained soils)
UNNAMED (Loamy over
mixed sandy, and
loamy, well drained
soils)
MILES
Source: University
of Minnesota 1969
23
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FIGURE I1-4 SOLL LIMITATIONS FOR ON-SITE SYSTEMS FOR SELECTED SITES
IN THE OTTER TAIL STUDY AREA (SITES 1&2)
LEGEND
! SLIGHT LIMITATIONS
MODERATE LIMITATIONS
SEVERE LIMITATIONS
MILES
Source: USDA-SCS
Undated
24
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FIGURE II-5 SOIL LIMITATIONS FOR ON-SITE SYSTEMS FOR SELECTED SITES
IN THE OTTER TAIL STUDY AREA (SITES 3&4)
LEGEND
11 SLIGHT LIMITATIONS
MODERATE LIMITATIONS
SEVERE LIMITATIONS
MILES
0 I 2
Source: USDA-SCS
Undated
25
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FIGURE 11-6 SOIL LIMITATIONS FOR ON-SITE SYSTEMS FOR SELECTED SITES
IN THE OTTER TAIL STUDY AREA (SITES 5&6)
:.
LEGEND
SLIGHT LIMITATIONS
MODERATE LIMITATIONS
SEVERE LIMITATIONS
MILES
Source: USDA-SCS
Undated
26
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Soil Series
Table II-l
DESCRIPTION OF SOIL SERIES WITH BASIC CHARACTERISTICS
Description
Percent of
Study Area
Depth
(Inches)
Permeability
Inches/Hr.
Depth
to High
Water Table
(Inches)
Limltat iontf
for On-Slce
Waste Disposal Systems
Depth
to
Bedrock
(Inches)
Esthetvllle
Arvllla
Salida
Sioux
Hubbard
Due In
Isan
Marsh and
Feat
Lake Beaches
Deep, excessively drained,
sandy loam underlain by
sand and gravel
Well drained, sandy loam
underlain by gray-brown
sand and gravel
Shallow, excessively drained,
gravelly sandy loam
Excessively drained,
loamy sand underlain by
sand and gravel
Excessively drained
loamy sand, underlain
by sand
Poorly drained, loamy
sand underlain by
coarse Sand
Very poorly drained sandy
loam underlain by coarse
sand. High organic
content
Shallow lakes, ponds,
and sloughs which
support aquatic life.
Soil In peaty muck
or loamy mineral soil.
Mixed soil. Mostly
sand and gravel. Poorly
drained.
30X
55Z
10Z
<5X
<5I
0 - 13
13 - 18
18 - 60
0-7
7-16
16 - 60
0-8
8-12
12-60
0-8
8-60
0 - U
14 - 60
0-11
11 - 42
42 - 60
0-16
16 - 22
22 - 60
Variable
0-60
2.0 - 6.0
2.0 - 6.0
6.0 - 2.0
2.0 - 6.0
2.0 - 6.0
>6.0
6.0 - 20
>20
>20
2.0 - 6.0
>6.0
>6.0
>6.0
>6.0
>6.0
>6.0
>6.0
>6.0
>6.0
Variable
Variable
_ __-_
>72
>72
'72
>72
>72
24 - 60
0-36
0-4
12 - 48
Slight
Moderate - Slopes
Severe - Slopes, rapid
Permeability
Slight
Moderate - Slope
Severe - Slopes, rapid
Permeabil icy
Slight
Moderate - Slope
Severe - Slopes, rapid
Permeability
Slight
Moderate - Slouco
Severe - Slopes, rapid
Permeability
Slight
Moderate - Slope
Severe - Slope,
Permeability
Moderate - High
Water Table,
Permeabl 1 1 ty
Severe - poor
Drainage, Permeability
Shallow Depth to
Water Table
Severe - High
Water Table
Severe - Shallow
Water Table,
Variable Permeability,
Flooding
>60
>60
>60
>60
>60
>60
>60
Variable
NJ
vj
-------
Foroda
Fordville
Markey
Clontarf
Svcrdrup
Allevlal
Land
Poorly drained sandy
loom underlain by
Well drained loam
underlain by sand
and gravel
Very poorly drained,
muck surface layer
underlain by sand
Well drained sandy
loam underlain by
sand
Excessively drained
sandy loan, underlain
by sand
Mixed poorly cloud
soil material deposited
by rivers and streams
<5Z
<5*
<5Z
<5X
<5I
<5%
0-16
16 - 28
*>8 - 60
0-6
6-24
24 - 60
0-32
32 - 60
0-15
15 - 25
25 - 60
0-12
12 - 24
24 - 60
0-60
2.0 - 6.0
2.0 - 6.0
>6.0
0.6 - 2.0
0.6 - 2.0
>6.0
0.2 - 6.0
>6.0
2.0 - 6.0
2.0 - 6.0
>6.0
2.0 - 6.0
2.0 - 6.0
>6.0
Variable
12 - 72
>72
0-12
36 - 60
>72
12 - 60
Moderate - Permeability
Shallow Water Table,
Severe - Permeability,
High Hater Table
Moderate - Permeability
Severe - High
Water Table,
Penoe ability
Moderate - High
Water Table,
Permeability
Moderate - Slope,
Permeability
Severe - Flooding
High Water Table
>60
>60
>60
>60
>60
>60
Source: USDA - SCS, 1974-1977
University of Minnesota, Soil Atals 1969
fo
O>
-------
The western section also is characterized by rapidly
permeable, excessively drained, sandy loam soils underlain by
sand and gravel. The Arvilla and Estherville soil series
predominate in this area (SCS 1974-1977).
The low-lying section between Otter Tail Lake and Lake Blanche
has sandy, poorly drained soils with a seasonally high water
table. The major soil series within this area have not been
identified (University of Minnesota 1969).
The section bordering Otter Tail River between Otter Tail Lake
and Deer Lake has poorly drained, marshy organic soils. The
organic peat series predominate here (SCS 1977).
Much of the shore area along Otter Tail Lake is composed of a
mixed sandy and gravel soil. Seasonal water table ranges from
12 inches to 48 inches and the soils are poorly-to-moderately
well drained. The Lake Beaches soil series predominates in
the shoreline areas (SCS 1977).
The south central section of the shoreline contains poorly
drained, loamy sands underlain by coarse sand. Seasonal water
table in this area ranges from 0 to 60 inches. The Beulm and
Isan soil series are present in this area (SCS 1977).
Marsh soils are found in the various wetlands south of Otter
Tail Lake between the Otter Tail River outlet and Lake
Blanche.
Recently deposited materials (alluvial''" soils) are found along
Balmoral Creek and the Otter Tail River. These are poorly
drained silt loams and clay loams (SCS 1977).
c. Soil Suitability for On-Site Disposal Systems
Successful treatment and disposal of municipal wastewater by septic
tank soil absorption systems depends on site conditions. A discussion
of the importance of soil characteristics for on-site wastewater dis-
posal systems is presented in Appendix A-l. The factors considered in
determining site suitability include:
Depth to bedrock,
Depth of water-bearing strata,
Elevation of seasonally high water table,
Rate of permeability of the soils, and
Gradient of the terrain.
Appendix A-2 lists specific criteria used by SCS for each of these
factors placing slight, moderate or severe limitations on the use of
on-site systems. The soils suitability for specific sites mapped by SCS
is shown in Figures II-4 through 11-6. The upland soils, set back from
the shoreline, are generally suitable for on-site disposal systems; they
are not restricted by the high water table as are soils along the shore-
line. Highly permeable soils and a high water table restrict the use of
29
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NORTHWEST
SHORE
TREATMENT SITE
SOUTH SHORE
TREATMENT SITE
FIGURE 11-7
PROPOSED LOCATION OF LAND APPLICATION SITES WITHIN
THE OTTER TAIL STUDY AREA
sis!
LEGEND
PROPOSED LAND APPLICATION SITES
MILES
0 ' 2
Source: Kerfoot 1979
30
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on-site systems along approximately one-half of the Otter Tail Lake
shoreline (by correspondence, Ulteig Engineers to James Warner, MPCA, 14
March 1977).
d. Soil Suitability for Land Application
While major factors determining soil suitability for land appli-
cation resemble those for on-site systems, the specific criteria differ.
Appendix A-3 shows specific criteria for land application by spray
irrigation and rapid infiltration. Soils suitability were among the
criteria used in selecting the suitable land application sites shown in
Figure II-7.
e. Prime Agricultural Lands
The SCS has established guidelines for a national program to inven-
tory prime and unique farmland, as well as other farmlands of statewide
or local importance (42 F.R., 23 August 1977). Any action (such as
construction of interceptor sewers, highways, buildings) tending to
impair the productivity of agricultural land is of concern to SCS
because it may reduce capacity to produce food, fiber, feed, forage and
other crops. The SCS, in cooperation with interested State and local
agencies, is inventorying these lands to determine the potential effects
of construction and development. Because the Otter Tail County Soil
Survey has not yet been completed by SCS, no land around Otter Tail has
been officially designated as prime or unique agricultural lands (by
telephone, Jerry Nesseth, SCS, 23 October 1978). However, a number of
farms in the northeast and western portions of Otter Tail Lake have
historically produced high yields of potatoes. Upon completion of the
SCS soil survey, these farmlands should be designated as prime agri-
cultural land (by telephone, Lawrence Streif, County Agriculture
Extension Agent, 20 October 1978).
4. ATMOSPHERE
a. Climate
The continental climate of the Otter Tail Lake area is character-
ized by relatively long cold winters and warm comfortable summers.
Appendix B-l summarized climatological data.
Neither the United States Department of Commerce nor the National
Oceanic and Atmospheric Administration (NOAA) maintains a weather sta-
tion in the Otter Tail Lake Study Area. Those nearest to the Study Area
are in Fergus Falls and Wadena (16 miles southwest and 22 miles east of
Otter Tail Lake, respectively). Data from these stations have been
averaged to approximate climatological values for the Otter Tail Lake
area. This approach is reasonable, as the Study Area lies approximately
midway between Fergus Falls and Wadena, and the elevation of all three
areas is similar.
Temperature. Study Area temperatures show a wide seasonal varia-
tion. The average annual temperature at the Study Area is 41.5°F, with
an average maximum temperature of 73.5°P during July and an average
31
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minimum temperature of 9.6°F during January. Cold, arctic air masses
occasionally drop temperatures to -30°F (NOAA 1973). Warm, moist trop-
ical air masses from the Gulf of Mexico can cause summer temperature
high of 115°F (West Central Regional Development Commission 1977).
Precipitation. The average annual Study Area precipitation is
25.94 inches. Rainfall is greatest during June (4.07 inches), and least
in January (0.78 inches) (NOAA 1973). Most of the precipitation falls
during the 138-day (average) growing season. Annual snowfall for the
area rarely exceeds 45 inches, but snowfall exceeds 1 inch on an average
of 17 days per year. The mean annual relative humidity is approximately
69%.
Wind Speed and Direction. The seasonal prevailing direction and
mean wind speed (miles per hour) in the Study Area are as follows:
Winter: east-southeast8 miles per hour.
Spring: southeast9 miles per hour.
» Summer: southeast (in August the prevailing winds are to the
north)--7 miles per hour.
t Fall: southeast--8 miles per hour.
The annual prevailing wind direction is from the northwest to the
southeast at 8 miles per hour (US Environmental Data Service 1968). No
wind is detectable during approximately 2% of the year.
b. Odors
Presently, there are no quantified reports or surveys on odors from
the Study Area. Because there is no record of letters or telephone
calls from local residents complaining of nuisance odors, it is likely
that nuisance odors are not a serious problem in the Study Area.
c. Noise
Apart from road traffic and motorboat noise, the Study Area is
relatively quiet. Sounds of long duration at annoying levels are not
present in the Study Area.
d. Air Quality
Otter Tail County is in a Minnesota PSD (Prevention of Significant
Degradation) Class 2 Zone. This indicates that the area currently meets
National Ambient Air Quality Standards (see Appendix B-2) and that
enforcement of the Clean Air Act Amendments of 1977 will prevent signi-
ficant air quality degradation. The Study Area has no air quality
testing station at the present time. However, a high-volume sampler is
located in Fergus Falls, where daily readings of suspended particulates
are made. Although air quality is generally good, readings at this
station show that in 1976 Minnesota secondary 24-hour ambient air
quality standards for total suspended particulates were exceeded twice,
on 15 October and 2 November.
32
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B. WATER RESOURCES
1. WATER QUALITY MANAGEMENT
The Federal government, the locality and the State are responsible
for various aspects of water resources management. Water resources
management includes municipal water supply, maintenance of navigable
waters, irrigation, and protection of the productivity of the soil. Of
such activities, preservation or restoration of the quality of US waters
is among the most important to the locality, the State, and the Federal
government. The Federal Water Pollution Control Act (P.L. 92-500, 1972)
and its 1977 amendments (P.L. 95-217) outlined a framework for compre-
hensive water quality management which applied to groundwater as well as
to surface waters.
a. Clean Water Act
Water quality is the responsibility of the EPA in coordination with
the appropriate State agency, in this case the Minnesota PCA. However,
with passage of the Clean Water Act, all Federal agencies were
instructed to safeguard water quality standards in carrying out their
respective missions. As the lead agency, EPA coordinates the national
effort, sets standards, and reviews the work of other agencies, some of
which are assigned responsibilities in line with their traditional
missions. For example, the Army Corps of Engineers maintains its juris-
diction over dredging permits in commercially navigable waters and their
adjacent wetlands and in coastal waters but now must also consider water
quality. The Coast Guard keeps its jurisdiction over oil spill cleanup.
The Act officially draws certain other agency activities into the water
pollution control effort. For example, it authorizes Federal cost-
sharing in agricultural projects designed to improve water quality by
controlling farm runoff. In the case of the SCS, these new responsibi-
lities may be in addition to or may dovetail with existing SCS programs
to reduce soil erosion, or to construct headwaters impoundments for
flood control.
In delineating the responsibilities of the various levels of govern-
ment for water quality, Congress recognized the rights of the states
with regard to their waters. It authorized aid to the states in funding
the development of plants for control of pollution, development of State
water quality standards (which may be more restrictive than Federal
standards), and research. When a state meets certain criteria, it is
certified by EPA as responsible for the administration of the activity
in question. The EPA may deny certification, but in all cases it
retains power of enforcement of established standards, whether State or
Federal. (Minnesota is one of the states granted certification by EPA.)
Among the goals and deadlines set in the Clean Water Act are these:
"it is the national goal that the discharge of pollutants into the
navigable waters be eliminated by 1985...
33
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"an interim goal of water quality which provides for the protection
and propagation of fish, shellfish, and wildlife and provides for
recreation in and on the water (is to) be achieved by July 1,
1983".
This landmark legislation requires publicly owned treatment works
discharging effluent to surface waters at least provide secondary treat-
ment, i.e., biological oxidation of organic wastes. It directed that
municipalities must provide the "best available technology" by 1983 and
that in appraising their options localities must address both the
control of all major sources of stream pollution (including combined
sewer overflows and agricultural, street and other surface runoff) and
the cost-effectiveness of various control measures. The use of uncon-
ventional technologies must also be considered.
The key provisions on water quality planning stipulate that to
receive aid a state must provide a continuing planning process. Part of
Section 208 requires the states to inventory all the sources of pollu-
tion of surface and ground waters, both point"" and non-point*, and to
establish priorities for the correction of substantial water quality
problems within a given area. The 208 plans are intended to provide an
areawide and, taken together, a statewide, framework for the more local
decisions on treatment facilities.
Section 201 of the Act (under which the Otter Tail Lake area appli-
cation for funds was made) authorizes EPA to make grants to localities
for the improvement of treatment facilities or other remedies of exist-
ing water quality problems. EPA may determine whether an Environmental
Impact Statement is required on a proposed project (see Section I.B),
and even where the State has been certified and assumes responsibility
for water quality, EPA retains the authority to approve or reject appli-
cations for funds for the construction of treatment facilities.
The local political jurisdiction has traditionally been responsible
for meeting the wastewater treatment needs of the community. Local
jurisdictions now have the benefit of Federal and State assistance in
meeting water quality standards and goals.
b. Federal Agency Responsibilities for Study Area Waters
EPA
Administers the Clean Water Act
Sets Federal water quality standards
EPA Region V
Administers the grant program described above for the Great
Lakes Region.
Provided partial funding for the preparation of the Otter Tail
Lake Area Facility Plan. Region V's responsibilities in the
construction grant program in general and specifically toward
the application made in the Facility Plan are discussed in
Section I.B.
34
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US Army Corps of Engineers
Controls dredging and construction activities in commercially
navigable streams, their 100-year floodplains and adjacent
wetlands through a permit system.
US Department of Agriculture
Under the Rural Clean Water Program will provide cost-sharing
money for soil conservation practices designed to improve
water quality. (This program will probably be assigned to
SCS.)
Soil Conservation Service (SCS)
Agency's mission is to control wind and water erosion, to sus-
tain the soil resource base and to reduce deposition of soil
and related pollutants into the water system.
Conducts soil surveys. Drew up guidelines for inventorying
prime or unique agricultural lands.
Works with farmers and other land users on erosion and sedi-
mentation problems.
Gathers information at the county level as part of program of
study and research to determine new methods of eliminating
pollution from agricultural sources.
Fish and Wildlife Services
Provides technical assistance in development of 208 plans.
c. State Responsibilities in the Otter Tail Lake Study Area
The following entities have responsibilities for water quality
management in Minnesota:
Minnesota Pollution Control Agency (MPCA)
Implements water pollution control laws and establishes regu-
lations. This agency has authority to issue permits to dis-
charge pollutants into surface waters under the National
Pollutant Discharge Elimination System (NPDES) and to set
discharge levels. MPCA also establishes criteria and stand-
ards applicable to interstate and intrastate waters. The
standards are being revised and are in draft form as of May
1979. MPCA conducted a water quality investigation of the
Otter Tail River above Fergus Fall in 1969. The investigation
included Otter Tail Lake and the data has been exaimed in this
EIS.
35
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Department of Natural Resources (DNR)
Identifies, categorizes and maintains existing natural
resources, including surface water bodies. DNR reviews county
actions and submits recommendations on industrial and agri-
cultural permits.
Department of Health
Reviews plans on public water and sewer improvements and
enforces drinking water standards.
d. Local Responsibilities for Water Quality Management
Land and Resource Management Office; Otter Tail County
Regulates the use of on-site disposal systems and other land
uses along shoreline areas through the Shoreland Management
Ordinance.
Local Zoning Ordinance. The townships of Otter Tail, Evert and
Girard have local zoning ordinances which enforce standards imposed by
the Shoreland Management Ordinance.
2. GROUNDWATER USE
Groundwater from the outwash aquifer is the principal domestic
water source. Extraction is primarily by small diameter homeowner
wells. Currently about 0.4 mgd are withdrawn from the aquifer for
domestic use within the Study Area. Usage will increase to about 0.5
by the design year 2000.
Several farmers in the area tap the groundwater aquifers to irri-
gate their fields and orchards. Figure II-8 shows the location of
irrigation sites determined from aerial photographs.
The outwash aquifer is being considered as a more extensive source
of irrigation water. Feasibility studies have shown that streamflow
from the area would not be depleted over a 10 year period of 1007o ground-
water development if not more than 6 inches of water per year were used
to irrigate the 190 square miles under study (Reeder 1972).
There is apparently an abundant supply of water for foreseeable
uses in the future. The lower sand beneath the outwash has been iden-
tified as an additional water supply source of great future potential
(Reeder 1972).
3. GROUNDWATER HYDROLOGY
The surficial deposits of glacial outwash found throughout the
Study Area are its major groundwater source. The glacial outwash
deposits cover an extensive area of some 350 square miles of Otter Tail
County (see Figure II-9). These outwash aquifers of stratified sand and
gravel vary in thickness from 50 feet in the east to about 100 feet in
36
-------
FIGURE II-8 LOCATION OF IRRIGATION FIELDS IN THE OTTER TAIL STUDY
AREA (BASED ON AERIAL PHOTOGRAPHS)
LEGEND
IRRIGATION FIELDS
MILES
Source: EPIC 1978
37
-------
BOUNDARY OF OUTWASH
AQUIFER
WATERSHED BOUNDARY
OTTERTAIL RIVER
WATERSHED
Battle Lake.
Clitherall
CROW WINS RIVER
WATERSHED
O 5
Source: Reader 1972
FIGURE II-9 AERIAL EXTENT OF OUTWASH AQUIFER
38
-------
the west of the Study Area. Sandy Loam and loamy sand overlie the
outwash aquifer at the surface and lenses of silt occur locally (Winter
et al. 1969). Throughout most of the Study Area the groundwater reserve
is under water table conditions; the surface of the water touches the
overlying zone of aeration. Occasionally, the groundwater is confined
locally (artesian conditions). Figure II-2 shows a cross-section of the
aquifer system found in the Study Area.
The depth to the water table varies from 0 to about 70 feet, but
usually is 5 to 30 feet. Shallowest depths occur in the northwest
section of the Study Area and in lakeshore areas, and greater depths are
found in the southeast (Reeder 1972).
The aquifer is generally underlain by clay up to tens of feet
thick, followed by other undifferentiated glacial deposits ranging in
thickness to about 200 feet. At least one sand layer aquifer exists
below the first massive clay layer (Reeder 1972). Potentially large
water supplies have been shown to exist in the deep sand layer.
The primary recharge"" source to the upper outwash aquifer is pre-
cipitation directly onto the surface. Precipitation within the Study
Area is estimated to be 24.0 inches per year. Of this amount 5 to 6
inches percolates into the groundwater, about 2.0 inches is runoff and
the remainder is lost through evapotranspiration (McGinness 1964; Reeder
1972; Winter et al. 1969). Recharge to the aquifer by underflow is
considered to be small. This is because the sands located along the
perimeter of the aquifer (see Figure II-9) have finer grain sediments,
low permeable till, and a smaller saturated thickness than the outwash
aquifer. Although the Otter Tail River and the small streams bring
surface water into the area they do not contribute signficantly to
groundwater recharge. Indeed the River appears to act more as a with-
drawal well from the aquifer.
The groundwater reservoir discharges water to the streams and low
lying lakes. Figure 11-10 shows the direction of groundwater flow. The
small surrounding lakes and terrain, which are slightly elevated with
respect to Otter Tail Lake, discharge groundwater towards Otter Tail
Lake. The hydraulic flow is strongest adjacent to the smaller lakes
because these lakes seek their own level by gravity and discharge the
underflow to Otter Tail Lake (Kerfoot 1979). Eventually this net inflow
is discharged into the Otter Tail River, where an estimated 4.5 mgd of
water leaves the aquifer as underflow. This very high groundwater flow
rate (as high as 10 to 15 feet per day) is apparently a major factor
affecting the operation of on-site treatment systems.
The many lakes in the area indicate an essentially full groundwater
reservoir. The very large storage in the aquifer sustains the lakes
during dry cycles (Winter et al. 1969).
Aquifer characteristics indicate that wells penetrating the full
thickness of the aquifer and developed to 100% efficiency can yield up
to 1200 gallons per minute (gpm) for 30 days of continuous pumping.
However, yields vary widely within short distances and yields of less
than 300 gpm can be expected in the area east and southeast of Otter
Tail Lake (Reeder 1972).
39
-------
FIGURE II-10 GROUNDWATER FLOW PATTERNS SURROUNDING OTTER TAIL LAKE
LEGEND
+~ GROUNDWATER FLOW DIRECTIONS
(BASED ON DARCY'S EQUATION)
-* GROUNDWATER FLOW DIRECTIONS
MEASURED BY THE GROUNDWATER
FLOW METER
MILES
1325- APPROXIMATE GROUNDWATER ELEVATION
40
Source: Kerfoot 1979
-------
4. GROUNDWATER QUALITY
Groundwater from the outwash aquifer is generally very hard,
ranging from 200-300 mg/1 (CaCOg). Hardness does not effect the suit-
ability of well water for consumption. Table II-2 shows water quality
data for 5 wells within the Otter Tail Lake area. MPCA drinking water
standards were exceeded for iron and manganese in 2 out of 5 and 3 out
of 5 samples, respectively. Nitrate and dissolved solids levels were
acceptable.
Table II-2
GROUNDWATER QUALITY DATA FOR
OTTER TAIL LAKE AREA
Dissolved
Well Iron Manganese Nitriates Solids
Depth (ft) Date (mg/1) (mg/1) (mg/1) (mg/1)
54 9/68 0.02 0.07 0.87 218
71 6/64 0.02 0.01 5.3 356
55 9/68 0.60 0.13 2.9 188
24 9/65 0.15 0.06 6.0 254
200 9/65 1.5 -- 0.13 208
Minnesota
Drinking H20
Standard 0.3 0.05 10 500
Source: Reeder 1972
As part of an ongoing sanitary survey (see Section II.C) resi-
dential wells are being sampled for coliform bacteria and nitrates.
Results are available for 31 wells located along the northeast and
southeast shores of Otter Tail Lake. Figure 11-11 shows the sampling
locations and the locations of wells containing high nitrate concentra-
tions or fecal coliform colonies. One sample, taken near the Otter Tail
River inlet, contained 13 mg/1 nitrates. This concentration exceeds the
public health drinking water standard of 10 mg/1. Water containing
nitrates in excess of the public health standard may cause methemoglo-
benimia* in infants who drink it. Three samples showed nitrate concen-
trations of 4.5-8.5 mg/1 and all other samples sowed low levels of
nitrates (<3.5 mg/1). Coliform bacteria were detected in 4 of the 31
samples. Only 1 sample, containing 10 colonies exceeded the Interim
Drinking Water Standards which require that potable water contain less
than 5 colonies per 100 ml. Contamination, however, cannot be verified
on the basis of one sample alone, and those samples which showed posi-
tive results for coliform bacteria will be reanalyzed.
In a separate study the Land Resources Management Office sampled 17
drinking water wells from campgrounds, resorts and restaurants. The
samples were tested for total coliform bacteria and nitrates. Counts of
coliform bacteria were low for all samples. Nitrate concentrations
ranged from 0.2 to 18.0 mg/1. Three well water samples, with nitrate
concentrations of 17 or 18 mg/1, exceeded the public health drinking
-------
FIGURE 11-11
LOCATION OF WELL WATER SAMPLES (JULY-AUGUST
1979, SANITARY SURVEY)
LEGEND
C COLIFORM
N NITRATES >4.5mg/l
F FECAL COLIFORM
MILES
42
-------
water standard. The problem of high nitrate concentrations in these
three wells was alleviated by upgrading suspected on-site treatment
systems (by telephone, Richard Astrup, Land Resources Office, 29 May
1979).
5. SURFACE WATER HYDROLOGY
Otter Tail Lake, Lake Blanche, Long Lake, Walker Lake, Deer Lake,
Round Lake, and the Otter Tail River are the major surface water
resources in the Study Area (see Figure 11-12). The Otter Tail River
originates in the southwest corner of Clearwater County and flows south-
ward through a series of lakes until it turns westward, flowing through
Otter Tail Lake and Deer Lake toward Fergus Falls (MPCA 1969). In
addition to discharge from the river, Otter Tail Lake receives both
surface and groundwater flow from the smaller surrounding lakes Long
Lake, Walker Lake, and Lake Blanche. A brief stretch of the Otter Tail
River flows from the outlet of Otter Tail Lake into Deer Lake. Round
Lake, between Otter Tail Lake and Deer Lake, is a landlocked lake.
Physical characteristics pertaining to the hydrology of the surface
waters serve to describe and differentiate the lakes and streams in the
Study Area.
The balance of water in lakes is expressed by the basic hydro-
logical relationship in which changes in water quantity and quality are
determined by the inputs from all sources less the rates of loss. Each
income and loss varies seasonally and is governed by the characteristics
of the drainage basin, the lake basin and the climate. Table II-3
summarizes the major physical characteristics of Otter Tail, the small
surrounding lakes and their respective drainage basins, which are dis-
cussed in the next few paragraphs.
a. Size of Drainage Basins
The drainage basins of Otter Tail Lake, Lake Blanche, Long Lake
Walker Lake, Deer Lake, and Round Lake are 1140, 176, 3.5, 1.56, 1141,
and 0.5 square miles, respectively. Drainage basin topography deter-
mines the path the runoff will follow as it moves from higher to lower
elevations, as well as the concentrations of sediments and nutrients in
that runoff. The larger watersheds act as more significant catchments
of precipitation which is transferred as runoff to the lakes. Long Lake
and Round Lake occupy larger portions of their respective drainage
basins than do the other lakes. That is, for Long Lake and Round Lake
the drainage basin-to-lake surface area ratio is 2:1 while for Otter
Tail Lake, Lake Blanche, Walker Lake, and Deer Lake it is 49:1 or
higher.
b. Tributary Flow
The Otter Tail River is the major tributary in the Study Area. Its
flow is regulated by many lakes, potholes, partially drained marshes and
by dam operation intended to stabilize water levels in Otter Tail Lake.
The nearest USGS stream gaging stations are located on the Otter Tail
-------
CLEARWATER
- \ COUNTY
FIGURE 11-12
OTTER TALL RIVER WATERSHED -
AND USCS SAMPLING STATIONS
LEGEND
COUNTY BOUNDARIES
. OTTER TAIL RIVER WATERSHED /
USGS SAMPLING STATIONS
IN THE OTTER TAIL
RIVER WATERSHED
ABOVE FERGUS FALLS
LONG LAKE
OTTER TAIL COUNTY
MILES
Source: Minn. Poll*
ution Control Agency,
Division of Water
Quality 1969
l_N«wYork
Mills
44
-------
TABLE II-3
PHYSICAL CHARACTERISTICS OF STUDY AREA LAKES
PARAMETER
Lake Surface Area
Mean Depth
Maximum Depth
Volume
Drainage Area
Lake Surface Area:
Drainage Basin Area
Tributary Inflow
Water Retention Time
UNIT
Acres
Ft.(M)
Ft.(M)
Acre/ ft.)
(m3)
Acres (M2)
Unitless
cf s(cms)
OTTER TAIL
LAKE
14,746
(6.0xl06)
23
(7)
124
(37.8)
339,158o
(4.2xl08)
729,600
(1140)
49:1
145
(4.1)
LAKE
BLANCHE
1,352
(5.5xl06)
11
(3.4)
_
14,872-
(l.SxlO7)
112,640
(176)
83:1
28.5
(0.81)
LONG
LAKE
1,173
(4.7xl06)
5
(1.5)
16
(4.9)
5,865
(7.2xl06)
2,260
(3.5)
2:1
0.58
(0.016)
WALKER
LAKE
694
(2.8xl06)
11.3
(3.4)
29
(8.8)
7,842
(9.7xl06)
99,840
(156)
144:1
17.7
(0.5)
DEER
LAKE
(l.SxlO6)
10.4
(3.2)
25
(7.6)
4,752
(5.9xl06)
730,319
(1141)
1,600:1
193
(5.5)
ROUND
LAKE
162
(655,614)
9
(2.7)
10
(3.0)
1,458
(l.SxlO6)
3,366
(0.5)
2:i
0.04
(0.001)
years
2.43
0.7
9.5
0.57
0.03
6.0
Sources: 1. Winter, T.C., L.E. Bidwell, and R.W. Macclay, 1969. Water Resources of the Otter Tail River
Watershed, Westcentral Minnesota. Hydrologic Investigations Atlas HA-296. U.S. Geological
Survey, Reston, Va.
2. MPCA, Division of Water Quality, 1969. Report on Otter Tail River System above Fergus Falls.
3. Minnesota Department of Conservation, Division of Game and Fish, 1969. Field Work and base
map, Deer Lake and East Lost Lake, Otter Tail County.
4. By telephone, Minnesota Department of Natural Resources, Fish and Wildlife Division, Fisheries
Section, April 13, 1978.
5. Estimates, by telephone, Mr. Reedstrom, Minnesota DNR, April 28, 1978.
-------
River near Perham (15 miles upstream from Otter Tail Lake), at German
Church (16 miles downstream from the Lake), below the Pelic.m River near
Fergus Falls (28 miles below the Lake), Orwell Reservoir, near Fergus
Falls (30 miles downstream) and below Orwell Dam, near Fergus Falls (32
miles downstream) (see Figure 11-12). All lie outside t'. Study Area.
The most complete historic stream flow information has come from
the continuously recording station at Orwell Dam (USGS 1977). At this
station, the drainage area spans 1830 square miles. Over a 47 year
period average stream flow has been 300 cubic feet per second (cfs).
Average annual stream flows, lake inflows, and lake outflows were
determined by Winter, Bidwell, and Maclay (1969) for basins including
the Study Area along the Otter Tail River . As estimated from the map
illustrating these features, the average flows at the inlet and outlet
of Otter Tail Lake were 145 cfs and 143 cfs, respectively. Low and high
flows were also computed (Winter et al. 1969). The 7-day 10-year low
flow at German Church was 30 cfs and the 7-day 10-year high flow was 700
cfs.
c. Lake Hydraulic Retention Time
Assuming complete mixing, the retention time of a lake is the time
required for natural processes to replace the entire volume of its
water. Long Lake (9.7 years), Round Lake (6.0 years), and Otter Tail
Lake (2.4 years) have much longer retention times than Lake Banche (0.7
years). Hydrological and morphological factors -- total tributary flow
and volume account for the difference. In addition to these natural
factors the hydraulic retention time of Otter Tail Lake is also arti-
ficially controlled by the operation of a dam at the Otter Tail River
outlet.
d. Precipitation
Mean annual precipitation in the Study Area is 23.7 inches (MPCA
1969). Most of the precipitation is returned to the atmosphere by
evapotranspiration; the remainder runs off or enters the groundwater.
The quantity of precipitation decreases from east to west over the
entire drainage basin, causing a difference of more than 2 inches of
runoff within the northeastern portion of the Study Area and between 1
and 2 inches of runoff in the southeastern portion (Winter et al. 1969).
e. Hydraulic Budget
A generalized hydraulic budget for a lake includes the hydraulic
inputs such as tributary inflow, precipitation and groundwater inflow
and the outputs such as tributary outflow, evaporation, and groundwater
recharge. The hydraulic budget for Otter Tail Lake is summarized in
Table II-4. Evaporation and groundwater were determined by the differ-
ence between the total input and total output for the lake. The infor-
mation was derived from USGS Hydrological Atlas (Winter et al. 1969).
-------
TABLE 11-4
WATER BUDGET FOR OTTER TAIL LAKE (1969)
IN 106 M3/YR FROM USGS HYUROLOGIC ATLAS (1969)
OTTER TAIL LAKE
Otter Tail River 129.5
Lake Blanche, Outlet (Balmoral Creek) 25.9
Walker Lake Outlet 17.0
Precipitation 35.8
TOTAL 208.2
Outputs
Outlet 127.7
Evaporation & Ground-water (by difference) 80.5
TOTAL 208. 2
47
-------
6. SURFACE WATER USE AND CLASSIFICATION
MPCA (1969) reported that the Otter Tail County lakes provide
recreational opportunities for fishing, swimming, boating, and water-
skiing. Similar opportunities are found in the Otter Tail River, which
also is used as a public drinking water supply for Fergus Falls. The
Otter Tail River, Otter Tail Lake, and Deer Lake have been assigned a
use classification by the MPCA of 1C, 2A, 2B, 3B (MPCA 1973). This
implies that these water bodies must meet the water quality requirements
intended to protect fish and aquatic life and support recreation but not
the requirements intended to protect drinking water. Their uses are
regulated under Minnesota water quality standards (see Appendix C-l).
7. SURFACE WATER QUALITY
This section deals with the quality of the water in Otter Tail
River, the local streams, and in Otter Tail Lake, Lake Blanche, Long
Lake, Walker Lake, Deer Lake, and Round Lake. The discussion considers
streams and lakes separately. First, water quality data collected from
the Otter Tail River and local streams in the Study Area are reported
and examined. Second, nutrient loading characteristics, quality of open
water, phosphorus loading trophic condition relationship, shoreline
conditions, and bacterial contamination of the lakes are studied. The
presentation synthesizes the limited available data on water quality of
the surface water resources in the Study Area. Most of the information
presented is summarized from investigations conducted by MPCA (1969) and
Kerfoot (1979). Further water quality analysis of Otter Tail Lake is
being conducted during the summer of 1979 in conjunction with a "septic
snooper" survey.
a. Streams
MPCA studied the Otter Tail River in July of 1969 and found the
water quality good. At the inlet of Otter Tail Lake total phosphorus
was 0.02 mg/1. Concentrations of nitrogen compounds were as follows:
Ammonia nitrogen (0.07 mg/1), organic nitrogen (0.73 mg/1) nitrite
nitrogen (0.02 mg/1) and nitrate nitrogen (0.02 mg/1). During the same
period dissolved oxygen was 8.9 mg/1, pH was 9.3, and total coliform
group bacteria were measured to be 80 colonies per 100 ml and 20 fecal
coliforms colonies per 100 ml. MPCA (1969) also sampled the outlet of
the East Lost Lake, which is immediately south of Deer Lake, outside the
Study Area, and found comparable levels: 0.07 mg/1 total phosphorus,
0.04 mg/1 soluble phosphorus, 0.06 mg/1 ammonia nitrogen, 0.72 mg/1
organic nitrogen, 0.02 mg/1 nitrite nitrogen, 0.02 mg/1 nitrate nitro-
gen, 9.3 mg/1 dissolved oxygen, pH 8.1, and 20 colonies of fecal coli-
forms per 100 ml.
In a more recent survey conducted during the period from 22 March
through the end of April 1979, Kerfoot (1979) sampled the Otter Tail
River at the inlets and outlet of Otter Tail Lake. He found seasonally
lower concentrations of total phosphorus (0.016 mg/1 and 0.018 mg/1 at
the inlets; 0.011 at the outlet), soluble phosphorus (0.002 mg/1 and
0.003 mg/1 at the inlets; 0.001 mg/1 at the outlet), and fecal coliforms
(0-2 fecal coliforms/100 ml at the inlets; 0 fecal coliforms/ 100 ml at
the outlet).
48
-------
The other streams affecting the water quality in Otter Tail Lake --
Long Lake Canal (Long Lake outlet), Balmoral Creek (outlet of Lake
Blanche), and the outlet of Walker Lake were also sampled. Results
showed a lower dissolved oxygen concentration and higher bacterial
levels in Long Lake Canal than in the Otter Tail Kiver or the other
tributaries. On the other hand, Walker Lake and Balmoral Creek exhibit-
ed water quality conditions similar to those of the Otter Tail River.
b. Lakes
To date, the most extensive field investigation on the Otter Tail
Lakes was conducted by the Minnesota Pollution Control Agency (MPCA) in
the summer of 1969 (see Appendix C-2) . Table II-5 summarizes data on
those parameters analyzed. Water quality conditions on Otter Tail Lake
cannot be evaluated conclusively based on one sample because of the
seasonal variability in nutrient loads, and tributary flow. Subsequent
to the 1969 sampling, only the transparency in terms of Secchi disc
depth has been measured regularly in Otter Tail Lake. The most recent
measurements of this parameter (11.5 ft to 14.5 ft in June 1975 and 7.5
ft to 10.0 ft in July and August 1975) indicate that the lake is meso-
trophic to oligotrophic.
Recently, Kerfoot (1979) conducted a winter study on these lakes in
an effort to determine the nutrient contribution from septic tanks to
these lakes (see Appendix C-3). He reported total phosphorus concen-
trations of 0.010 mg/1 and 0.024 mg/1 in the open water of Otter Tail
Lake. However, neither MPCA's investigation nor Kerfoot's study pro-
vided sufficient information to allow a complete interpretation of water
quality conditions in the lake.
Nutrient Loading Characteristics. Nutrient loads to Otter Tail
Lake, Lake Blanche, Long Lake, Deer Lake, Walker Lake and Round Lake are
shown in Table II-6 for the major nutrient sources including tribu-
taries, precipitation, septic tanks and runoff from the immediate water-
shed. Figure 11-13 shows the relative distribution of phosphorus from
various sources. Because phosphorus is the limiting nutrient controll-
ing the trophic status of most temperate lakes and because it is more
easily controlled than nitrogen, it is usually the focus of attention in
lake water quality management.
Nutrient loads were determined using the following data and assump-
tions :
MPCA (1969) water quality data was used to determine the
tributary load.
Loads from precipitation and septic tanks were developed using
the assumptions derived from the National Eutrophication
Survey (NES). This survey was an investigation on a nation-
wide basis of potential acceleration of eutrophication to
fresh water lakes and reservoirs. These values are generali-
zations and cannot account for site-specific conditions. The
NES estimate for septic tank loadings is probably conserva-
tively low for Otter Tail Lake. Kerfoot found that the sandy
49
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TABLE II-5
SELECTED WATER QUALITY PARAMETERS
Water Qual iLy
Parameter _
Mean
Total Phosphorus
(mg/1)
Mean
Total Nitrogen
Mean Transparency
(fee:)
Mean
Dissolved Oxygen
Survey
Date
July, 1969
Aug., 1972?
July, 1969
July, 1969
Aug., 1972 .,
Summer 1975"
July, 1969
LAKES
Median
Total Colifortns
(MPN/100 ml)
Chlorophyl
(mg/1)
July, 1969
1970-19764
Aug., 1972
Otter Tail
-
0.74
7.3
Walker
0.04
0.035
1.03
4.5
6.0
Ueer
0.035
0.018
0.70
8.7
10.0
Blanche Round
0.05 0.04
0.83 1.30
6.5
Long
.
-
10.5
8.8
20
8.1
20
8.9
45
8.7
9.0
20
8.9
20
1100
No t e s;
(1) Samples c u 11 uv t ed and analyzed by the Mimu-hOta Pollution Control Agency in July of 1969.
(2) Samples collected and analyzed by Minnesota Department of Natural Resources in August, 1972.
(3) Samples collected and analyzed by Otter Tall Lake Citizen's group every week from June through August of 1975.
(4) Samples collected and analyzed by Fergus County Health Department 1970-1976.
-------
Table II-6
Nutrient Budgets for Otter Tail Lake,Deer lake, Walker Lake,
Round Lake,Long Lake and Lake Blanche
Otter Tail Lake
Inpjuc
Precipitation
Septic Tanks
Tributaries
Immediate Drainage
Input
Precipitation
Septic Tanks
Tributaries
Immediate Drainage
Input
Precipitation
Septic Tanks
tributaries
Immediate Drainage
Phosphorus
1,020.0
261.7
6,238.6
60.0
7 , 580 . 3
Deer Lake
Phosphorus
31.4
16.6
10,659.8
1.8
10,709.6
Walker Lake
Phosphorus
47.7
4.6
977.4
19.7
1,049.4
7.
13.5
3.5
32.2
0.8
100
Z
0.3
0.2
99.5
<1
100
7.
4.5
0.4
93.2
1.9
100
Nitrogen
64,451.2
9,839.9
212,629.4
2,327.4
289,247.9
Nitrogen
1 .997.5
624.2
194,539.7
57.3
197,218.7
Nitrogen
3,033.3
173.0
25,417.8
623.5
29,247.6
%
22.3
3.4
73.5
0.8
100
%
1.0
0.3
98.6
<1
100
7.
10.4
0.6
86.9
2. 1
100
Tnpu^t
Precipitation
Septic Tanks
Tributaries
Immediate Drainage
Input
Precipitation
Septic Tanks
Tributaries
Immediate Drainage
Round Lake
Phosphorus
11. i
5.9
1.3
!8.3
Long Lake
Phosphorus
80.7
1.3
23.7
105.7
62
32
7
Too"
73.4
1.2
22.4
100
Nitrogen
708.0
230.1
40.0
978.1
Nitrogen
5,126.6
48-9
678.8
5,354.3
%
72
24
4
100
87.6
0.8
11.6
100
Lake Blanche
Input
Precipitation
Septic Tanks
Tributaries
Immediate Drainage
Phosphorus
93.0
9.4
3,546.0
10.9
3,659.3
2.5
0.4
96.9
3.0
100
Nitrogen
5,909.2
353.4
33,053.3
295.5
39,611.3
%
14.9
0.9
83.4
0.8
100
-------
1%
10,000
9,000
8,000
7,000
-
o 6,000
2
to
D
fL
O
X
0.
I
a.
5,000
4,000
H 3,000
O
I-
2,000
1,000
99%
DEER
LAKE
82%
3%
97%
LEGEND
NON-POINT SOURCE
(TRIBUTARIES)
NON-POINT SOURCE
(IMMEDIATE
DRAINAGE)
PRECIPITATION
SEPTIC TANKS
IMMEDIATE DRAINAGE,
PRECIPITATION,
SEPTIC TANKS
7%
93%
OTTER TAIL
LAKE
LAKE
BLANCHE
WALKER
LAKE
100
75
Q
O
_l
(0
5? 50
o
x
0.
o
X
0.
25
77%
22%
LONG
LAKE
32%
61%
CM
ROUND
LAKE
FIGURE 11-13 COMPARISON OF PHOSPHORUS LOADINGS BY SOURCE CONTRIBUTION
FOR LAKES IN OTTER TAIL STUDY AREA
-------
soils and high rates of groundwater flow result in poor
adsorption of phosphorus in the soil matrix and finally in
high rates of septic discharge to surface waters. One condi-
tion, specific to Otter Tail Lake was, however, accounted for
in determining septic tank loads. Kerfoot (1979) observed
that ST/SAS downslope of Lakr Blanche, Walker Lake, and Long
Lake discharged to Otter Tail Lake rather than to the respec-
tive smaller lakes. Septic Lank loads were determined assum-
ing the condition.
Finally, a model developed by Omernik (1976) was used to
determine nutrient loads from the immediate watershed. The
relationship between land usf categories and the total phos-
phorus and total nitrogen export rates was developed by
Omernik using tributary data collected from non-point source
watersheds in this geographic region. The EPA National Eutro-
phication survey has adopted Omernik's model as their stan-
dandard methodology for estimating nutrient export from
immediate watershed areas. This model is duscussed in detail
in Appendix C-7.
The results of the nutrient load analysis indicate that tributary
inflow contributes the most significant nutrient load to Otter Tail
Lake, Walker Lake, Deer Lake, and Lake Blanche. Precipitation is the
major nutrient source to Round Lake and Long Lake as well as an signi-
ficant source to the other lakes. Septic tanks contribute a relatively
small percentage of the total nutrient load to all lakes except Round
Lake. Round Lake, a landlocked lake with a small watershed area
receives a very small nutrient load from non-point sources.
The nutrient loadings presented in this section reflect the best
available estimate using the limited data available. However a more
comprehensive sampling program might result in modifications of the
loading estimates.
Phosphorus Loading/Trophic Conditions Relationships. This section
examines the relationship between phosphorus loadings and the resultant
water quality and lake trophic status. Phosphorus concentrations
generally control the standing crop of algae and therefore the trophic
status of most lakes.
In order to determine the relationship between phosphorus loads and
water quality, an empirical model developed by Dillon was used. A
detailed discussion of this model is included in Appendix C-7. Essen-
tially the model predicts in-lake concentrations of phosphorus and lake
trophic status as a function of mean depth, annual phosphorus loading,
the hydraulic flushing rate and a phosphorus retention coefficient. The
Dillon relationship was found to be applicable to 23 lakes in the east-
ern United States which were sampled during the National Eutrophication
Survey.
Figure 11-14 shows the trophic condition for Otter Tail Lake, based
on the Dillon model. The analysis indicates that Otter Tail Lake is
53
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I I I I I I I I I
ROUND LAKE
I I I I I I I I
0.01
.008
10.0
MEAN DEPTH(METERS)
100.0
L= AREAL PHOSPHORUS INPUT (g/m7yr)
R=PHOSPHORUS RETENTION COEFFICIENT
P= HYDRAULIC FLUSHING RATE (yr"1)
FIGURE 11-14 TROPHIC STATUS OF OTTER TAIL AND ROUND LAKES
UNDER EXISTING CONDITIONS
-------
mesotrophic, a condition concistent with the analysis of Secchi disk
data discussed in the examination of open water quality. The model has
not been used to determine the trophic status of the small surrounding
lakes, Long Lake, Walker Lake, Deer Lake and Lake Blanche. Data is very
limited for these lakes and the trophic status could not be predicted
with much confidence. However, existing data suggest that the trophic
status is not significantly influenced by nutrient input from septic
tanks for any of these lakes; ST/SAS located along these lakeshores dis-
charge to Otter Tail Lake rather than the small surrounding lakes.
Because septic tanks represent a large percentage of the total nutrient
load to Round Lake, the determination of trophic status was considered
important. The model indicates that Round Lake currently oligotrophic;
although septic tanks contribute a large percentage of the nutrient
load, the total load is low relative to most of the Study Area lakes.
Nearshore Conditions. The MPCA study (1969) indicates that the
concentrations of phosphorus and nitrogen in the shoreline areas of
Otter Tail Lake were slightly higher than those in the open waters.
Similarly, Kerfoot (1979) observed elevated concentrations along the
northeastern and southwestern shoreline. Although dense patches of
aquatic vegetation have been detected in some areas from aerial photo-
graphs using infrared imagery, there is no definite correlation between
the location of septic leachate plumes and dense vegetation. Prelimi-
nary results (August 1979) of the sanitary survey indicate the algae
growth along the Otter Tail shoreline is sparse and that most dense
patches of vegetation are bullrushes and other rooted macrophytes
associated with wetland areas.
The lakes in this particular geographic region are alkaline. The
condition in itself may significantly affect the lake water quality in
terms of phosphorus concentrations. Under certain circumstances, chem-
ical precipitation in a hardwater environment effectively removes
phosphorus from the water column, making it unavailable to algae for
growth. Algal growth may be naturally regulated by this mechanism.
Kerfoot's analysis (1979) of groundwater phosphorus versus nearshore
surface water phosphorus concentrations suggests that phosphorus con-
centrations may be reduced by this mechanism of chemical precipitation.
Evaluation of the relationship between septic leachate and attached
plant growth is the subject of continuing studies by EPA, to be com-
pleted in August 1979.
Bacterial Contamination. Bacterial contamination has been investi-
gate dT71lPCA~TT969T7TergLis Falls County Health Department (1969-1976),
and Kerfoot (1979). MPCA's (1969) study uncovered relatively low con-
centrations of fecal coliforms, determined from coliform group organisms
as a Most Probable Number (MPN) per 100 ml in the nearshore and offshore
areas of each of the lakes. Frequently, less than 20 coliform group
organisms were found during the month of June (1969); this value was
well below the Minnesota fecal coLiform water quality standard of 200
MPN/100 ml for recreational waters. Results of the Fergus Falls County
Health Department investigations from 1969 to 1976 indicated varying
concentrations of coliform group colonies per 100 ml of sample at the
outlet of Otter Tail Lake, using the Millipore Filtration Test (see
Appendix C-4) . Unfortunately, these results cannot be analyzed in
55
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Q AHNIE}
^ WrLfl
LAKE }
FIGURE FT-15 FL(X)I) HAZARD AREAS IN THE OTTER TAIL STUDY AREA
LEGEND
FLOOD PRONE AREAS
MILES
Source: HUD
1976, 1977
56
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comparison with Minnesota State fecal coliform standards, because the
results are not expressed in units of MPN per 100 ml, nor was the samp-
ling frequent enough (5 samples per month) to interpret a geometric mean
as required in the Minnesota State regulations (MFC 14 1973). Kerfoot
(1979) found no indication of fecal coliform contamination in the lakes
during the winter period; concentrations were generally 0-2 MPN/100 ml.
8. FLOOD HAZARD AREAS
Figure 11-15 delineates the boundaries of the flood hazard areas
which have been mapped for the Study Area to date (HUD 1976-77). The
boundaries include the 100 year floodplain. A flood of this magnitude
occurs with a frequency of every one hundred (100 years), although in
actuality such a flood could occur at any time. The US Department of
Housing and Urban Development (HUD) has the overall responsibility for
designating flood hazard areas for the National Flood Insurance Program.
Flood hazard areas mapped by HUD are used in determining flood
insurance rates for special properties in a given area. Under the
National Flood Insurance Program, flood insurance is required in com-
munities with identified flood hazard areas. This program provides
insurance only for buildings; structures such as bridges, roads, or dams
are not insurable. When federal grants or loans are used to build any
structure in these areas, they must be insured.
The Otter Tail County Shoreland Management Ordinance (1973) has
established minimum standards for lot size, building setback, and sewage
disposal systems. The standards are applicable within 1000 feet from
the normal high water mark' of a lake or pond and 300 feet from a river
or stream on the landward extent of a flood plain. These standards are
designed to protect surface waters and flood prone areas.
C. EXISTING SYSTEMS
All homes and resorts in the Proposed Service Area are served by
on-site systems. At the time that the Facility Plan was drafted, little
was known about the types of existing systems, or the nature and extent
of problems with these systems. Such information was necessary to
determine the wastewater treatment needs for the Proposed Service Area.
Consequently, EPA undertook two studies which have provided additional
information on the nature and extent of these problems and is in the
process of conducting two additional studies.
The Land and Resources Management Office, which is responsible for
enforcing the County's Standards for use and construction on on-site
systems, also provided useful information for this analysis.
Facility Plan surveys of indirect indicators of system performance,
such as compliance with the Shoreline Management Act, were helpful but
not conclusive.
57
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1. SUMMARY OF DATA
This discussion briefly summarizes the studies that were recently
undertaken by EPA to evaluate existing systems.
a.. EPIC Survey (EPA 1978)
An aerial photographic survey was conducted by EPA's Environmental
Photographic Interpretation Center (EPIC) during August 1978 in order to
locate surface malfunctions within the Study Area. Only three surface
malfunctions were detected within the Proposed Service Area during the
survey and later confirmed by field investigation. Aerial photographs
have also been used to locate beds of aquatic vegetation but this infor-
mation was not confirmed by on-site investigation. The location of
surface malfunctions and suspected beds of aquatic vegetation are
illustrated in Figure 11-16.
b. Investigation of Septic Leachate Discharges, Otter Tail
Lake, Minnesota (Kerfoot 1979)
This study was initially undertaken during March 22 through April
30, 1979 to determine whether groundwater plumes from nearby septic
tanks were emerging along the lakeshore and causing elevated concentra-
tions of nutrients. A second septic leachate survey will begin in late
summer, 1979, to determine the effect of the seasonal population on
septic leachate discharges. Septic leachate plumes are detected with an
instrument referred to as the "Septic Snooper." This instrument is
equipped with analyzers to detect both organics and inorganics from
domestic wastewater. In the original winter survey this device was
towed along the ice-covered lake and holes were drilled through the ice
at 100 foot intervals to obtain a profile of septic leachate plumes
discharging to surface waters. Along the southwest and northeast shore
there was nearly a one to one relationship between the location of
groundwater plumes and the number of permanent residences. Areas with
high numbers of plumes were found adjacent to Lake Blanche, Walker Lake
and Long Lake and at the inflow of the Otter Tail River. The location
of plumes and bacterial sampling points are shown in Figure 11-17. A
determination of groundwater flow patterns indicated why plumes were
more dense adjacent to lakeshore areas. As Figure 11-10 illustrates,
Otter Tail Lake acts like a large withdrawal well and groundwaters flow
towards Otter Tail Lake along all but the western shoreline. Flow is
particularly rapid along those lakeshore areas adjacent to Long Lake,
Walker Lake and Lake Blanche. These lakes seek their own level by
gravity and discharge the underflow into Otter Tail Lake. The summer
sanitary survey should provide additional information on septic leachate
discharges, and particularly on the nutrient loads contributed by
ST/SAS.
58
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FIGURE 11-16 SUSPECTED BEDS OF AQUATIC VEGETATION AND LOCATIONS OF
SURFACE MALFUNCTIONS FROM ON-SITE SYSTEMS
(BASED ON AERIAL PHOTOGRAPHS)
LEGEND
FAILING SEPTIC TANK SYSTEMS
AQUATIC VEGETATION
DEVELOPED AREAS
Source: EPIC 1978
59
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FIGURE II- 17 LOCATION OF ERUPTING
AND STREAM SOURCE PLUMES
LEGEND
DORMANT PLUME
ERUPTING GROUNDWATER PLUME
ORGANIC SURFACE WATER PLUME WITH
DISSOLVED SOLIDS LOAD
I 2
Source: Kerfoot 1979
-------
FIGURE 11-17 LOCATION OF ERUPTING AND STREAM SOURCE PLUME (Cont'd.)
LEGEND
-o DORMANT PLUME
- ERUPTING GROUNDWATER PLUME
-* ORGANIC SURFACE WATER PLUME
B3 SAMPLING STATIONS
h H
Source: Kerfoot 1979
ONLY AREA BETWEEN BARS
SAMPLED
12
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c. Construction Grant Sanitary Survey for Otter Tail Lake,
(begun July 22, 1979)
A house-to-house sanitary survey of Lakeside systems is currently
being conducted to determine the types of on-site systems, the nature
and extent of problems with these systems, and the extent of violations
of the existing sanitary code. Approximately 25% of the lakeshore homes
will have been surveyed by the end of the summer when this study is
completed.
2. SHORELAND MANAGEMENT ORDINANCE
The Otter Tail County Shoreland Management Ordinance was adopted in
May 1973. The ordinance provides minimum standards for construction,
location and maintenance of on-site systems within Otter Tail County.
Prior to the time that this Ordinance was drafted there were no stand-
ards regulating the use and construction of on-site systems. Most
systems were constructed prior to the issuance of the ordinance and many
existing systems do not comply with the standards. The Land Resource
Office, the agency responsibile for enforcing the Shoreline Management
Ordinance indicated that at the close of 1977 about 185 existing systems
in or near the the Study Area were in compliance with the Sanitary Code.
An additional 24 holding tank permits were granted in 1978 (by tele-
phone, R. Astrup, Land Resources Management Office, May 1979), raising
the total percentage of systems which comply with the ordinance to about
15%. The County has been quite successful in enforcing the ordinance
for new construction; it is estimated that about 75% of the resorts
constructed over the past 5 years comply with the Sanitary Standards (by
telephone, R. Astrup, Land and Resources Management Office, May 1979).
Many non-complying systems constructed prior to the time that the
Ordinance was adopted, continue to operate in violation of the Ordi-
nance. Although the County has issued a number of abatement orders
which have been complied with, the County's policy has been to maintain
the status quo until the issues addressed in this EIS have been resolved
(by telephone, L. Krohn, Land and Resources Management, May 1979).
Under the provisions of the Shoreland Management Ordinance, on-site
systems must comply with the minimum standards detailed below and in
Appendix D.
A building sewer, septic tank and soil absorption unit con-
sisting of a subsurface disposal field and/or seepage pit(s)
are required. (Where unusual conditions exist, other disposal
systems may be permitted provided they comply with other
standards.)
A minimum separation distance of 50 feet between the soil
absorption system and the Otter Tail Lake shoreline. The
separation distance for the smaller lakes (Blanche, Walker,
Long, Deer and Round) is 75 feet.
62
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A minimum horizontal separation distance of 50 feet between
the disposal field or septic tank and any domestic water
supply.
Depth to seasonal high groundwater or exposed bedrock must be
a minimum of 4 feet.
The liquid capacity of the septic tank and the size of the
absorption area must conform to the standards outlined in
Appendix D.
Because there were no standards for construction and operation of
on-site systems prior to the Shoreland Management Ordinance and because
many of the lakeshore lots are severely limited by a high groundwater
level, many existing systems do not comply with the minimum standards of
the ordinance. Violations of the Ordinance fall into one or more of the
following categories:
Well Setback Distance. A minimum setback distance of 50 feet from
a drainfield or septic tank is intended to provide an adequate distance
for removal of bacteria and phosphorus and for dilution of nitrates.
Since the majority of wells in the area are sand points less than 50
feet deep this separation distance is important to avoid contamination
of well water. Approximately 40% to 50% of the lots along the lakeshore
do not meet minimum lot size requirements of 20,000 square feet. Small
lot sizes are most numerous along the west and northwest shores (see
Figure 11-18). It is probable that many of these same sites cannot meet
the well setback requirements.
Lake Setback Distance. A setback distance of 50 feet between the
drainfield and the lakeshore is intended to provide adequate distance
for removal of phosphorus and bacteria so that water quality is not
degraded. Of the homes along the Otter Tail Lake shoreline, 49% are
platted too close to the lake to meet the minimum building setback dis-
tance (by letter, Ken Skuza, Utleig Engineers to MPCA, March 1977).
Many of these same sites may violate minimum setback requirements for
soil absorption systems.
Depth to Groundwater. Figure 11-18 illustrates the extent to which
lakeshore homes comply with minimum standard for depth to groundwater.
Violations of this standard are most extensive along the southwest shore
and along shoreline areas adjacent to Walker Lake and Long Lake. Most
homes located along the east and southeast shore comply with this stan-
dard. Violation of the minimum separation distance could lead to poor
soils adsorption and consequently such public health problems as ground-
water contamination and ponding of effluent.
Sizing of Septic Tanks and Soil Absorption Systems. No information
is available on the extent of violations of minimum size requirements.
An undersized septic tank may result in backup of the effluent or poor
solids removal. The lifetime of the soils treatment unit will be reduc-
ed if solids are not properly removed in the septic tank. Cesspools,
leaching pits and undersized drainfield may not provide adequate renova-
tion and dilution of wastewater and would not be expected to last as
long as standard sized drainfields.
63
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FIGURE 11-18
66%
DEER [...,,
LAKE
DISTRIBUTION OF LOT SIZES AND
AND PERCENTAGE OF LOTS WITH
HIGH GROUNDWATER LEVELS (LESS
THAN 6 FEET TO GROUNDWATER)
LEGEND
LESS THAN 10,000 FT2
10, 001-20, OOOFT2
2
OVER 20,000 FT
= PERCENTAGE OF LOTS
COMPLYING WITH SHORE-
LAND MANAGEMENT
ORDINANCE REGARDING
DEPTH TO GROUND-
WATER
\WALKER
LAKSHg ;:5^>
35%/
32%
V1
73°/<
0'
31%
10%
30%
35%
i
0
I
(OTTER
(i TAn-
\' RIVER
79%
f.. \TfLICAN
"97%
MILES
i
2
Source: Utleig Eng. Inc.,
to MPCA, March 1977
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3. PROBLEMS CAUSED BY EXISTING SYSTEMS
Since the County has indicated that only about 15% to 20% of the
on-site systems comply with the standards outlined in the Shoreland
Management Ordinance, the potential for water quality and public health
problems needs to be investigated. The distinction should be made
between nuisance or community improvement problems on the one hand, and
public health or water quality problems on the other. Public health
problems may result from recurrent backups, ponding of effluent on the
soil surface and contamination of drinking water in excess of drinking
water standards. Bacterial contamination of water used for contact
recreation may also constitute a public health hazard. Water quality
problems resulting from use of on-site systems include discharge of
nutrients, bacteria or organics in excess of water quality standards or
in concentrations sufficient to change the lake trophic status.
Nuisance or community improvement problems include odors, shoreline
algal growth and limitations on dwelling expansions.
Ponding. The EPIC aerial photographic survey detected only one
failing system along the Otter Tail Lake shoreline (south shore) and two
surface malfunctions in the Village of Otter Tail. The location of
these failures is shown in Figure 11-16.
Backups. No information is available on the extent to which back-
ups are a problem for the Study Area.
Groundwater Contamination. Groundwater nitrate concentrations, in
excess of the public health drinking water standard have been found in
associations with improperly operating on-site systems. There is no
indication to date that this problem is widespread and the observed
problems were corrected by upgrading an improperly operating on-site
system(s).
Water Quality Degradation. The impact of septic tank leachate on
the water quality of Otter Tail Lake and the small surrounding lakes has
not been fully clarified. The following discussion summarizes the
available information on water quality effects of on-site systems and
points out the complications involved in trying to evaluate this prob-
lem.
Nutrient budget estimates for Otter Tail Lake and the small sur-
rounding lakes were discussed in Section II.B.7. It is estimated that
septic tanks contribute only about 37o to 4% of the total phosphorus load
to Otter Tail Lake. Septic tanks account for a similarly small percent-
age of the total phosphorus load to all the smaller lakes except Round
Lake (see Figure 11-17). Round Lake is land locked and consequently has
no non-point source tributaries. It is not apparent from these esti-
mates that septic tank leachate is contributing significantly to water
quality degradation (except in Round Lake).
Kerfoot (1979) investigated the problem of septic tanks leaching
into surface waters during an April 1979 "Septic Snooper" Survey (see
II.C.I and Appendix C-3). As Figure 11-17 illustrates, septic tank
65
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plumes were particularly dense along the southwest and northeast shore-
lines. The frequency of plumes correlated well with the number of
permanent residences. The soil and groundwater conditions around Otter
Tail Lake are such that septic tank leachate discharges to Otter Tail
Lake along most of the shoreline. These conditions are as follows:
Soils are generally sandy and moderately to rapidly permeable;
Groundwater flows towards Otter Tail Lake along all but the
western shore. Hydraulic head is strongest along the shore-
line areas adjacent to Lake Blanche, Walker Lake and Long Lake
and an unnamed lake northwest of Otter Tail Lake. These lakes
are slightly elevated with respect to Otter Tail Lake and the
underflow from these lakes discharges into Otter Tail Lake
(see Figure 11-10).
The significance of septic tank leachate on water quality depends upon
the following:
1) How effectively septic tank leachate breaks through to the sur-
face water. Breakthrough is most efficient in areas where groundwater
flow is most rapid. Under rapid hydraulic flow conditions, nutrients
from septic tanks are not adequately adsorbed as they pass through the
soil matrix. Therefore, nutrients break through from the groundwater
discharging into the surface water.
2) The fate of phosphorus once it reaches the surface water. In
terms of lake trophic status the availability of phosphorus becomes very
important. In marl lakes such as Otter Tail, phosphate and essential
micronutrients (especially iron and manganese) may form insoluble com-
pounds which are essentially lost from the photosynthetic zone. The
potential for eutrophication in marl lakes may increase rapidly if con-
ditions become such that phosphorus is no longer precipitated (i.e., if
buffering capacity and carbonate reservoir are reduced) and becomes
unavailable for algae growth.
Shoreline algae growth. While growth of algae is not necessarily
indicative of a water quality problem resulting from septic tanks, it is
considered a nuisance since it interferes with recreational activities
and may be aesthetically displeasing.
No investigation has been made to correlate the extent of algae
growth along the shoreline of Otter Ta^l Lake and the surrounding small-
er lakes with septic tank leachate. However, results of an aerial
photographic survey made during August 1978 have been used to locate
suspected beds of vegetation. These results have not yet been confirmed
by field investigation. Aquatic vegetation located by this method
includes emergent and submergent plant species as well as dense beds of
algae. Suspected beds of aquatic vegetation are shown in Figure 11-16.
Areas of dense vegetations are found between Long Lake and Walker Lake,
adjacent to wetlands on the south shore and in an area along the south
central shore. These locations do not uniformly coincide with areas of
high housing density or dense plume location. There is no indication
66
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Table II-7
THE RELATIONSHIP BETWEEN NUMBER OF SPECIES OF FISHES,
AREA, AND DEPTH FOR THE 6 LAKES IN THE STUDY AREA
LAKE
Otter Tail
Blanche
Round
Walker
Deer
Long
NUMBER OF NUMBER OF
SPECIES: SPECIES:
GAME FISH FORAGE FISH
16 4
12 0(?)
10 0(?)
7 0(?)
13 12
2 0
NUMBER OF
SPECIES:
ROUGH FISH
3
2
1
2
3
0
YEAR OF
DNR
STUDY
1973
1973
1975
1971
1962
1978
LAKE AREA
IN ACRES
14,746
1,352
162
694
457
1,173
MEAN LAKE
DEPTH IN FEET
23.0
11.0
9.0
11.3
10.4
5.0
-------
that septic leachate is contributing nutrients levels sufficient to
sustain significant shoreline algae growth. Preliminary results of the
Sanitary Survey indicate only sparse algal growth along densely popu-
lated lakeshore areas. Conceivably, nutrients discharged from septic
leachate form an insoluble precipitate with iron or manganese and are
not readily available for plant growth.
D. BIOTIC RESOURCES
1. AQUATIC BIOLOGY
a. Fisheries
The Minnesota DM has conducted surveys to determine the abundance
and diversity of fishes in the lakes of the Study Area. Except for Long
Lake, the lakes support large and varied fish populations. The degree
of species diversity and the composition of fish populations in a given
lake can indicate the water quality of that lake. For example, a lake
with trout, walleyes, and whitefish indicates generally good water
quality.
Otter Tail Lake, Lake Blanche, Walker Lake and Long Lake have been
classified by the Minnesota DM as follows:
Lake Management Classification Ecological Classification
Otter
Tail Walleye Walleye
Blanche Walleye, largemouth bass, Walleye, largemouth bass,
and panfish and panfish
Round Panfish (largemouth bass) Panfish and largemouth bass
Walker Panfish and largemouth bass Panfish and largemouth bass
The fact that the Lake Management Classification is the same as the
Ecological Classification indicates that the existing conditions in the
lakes will support populations of fish species that are consistent with
the DNR's management goals.
The 6 principal lakes in the Study Area support a variety of game,
forage, and rough fishes (see Appendix E-l). Although the lakes vary in
size and mean depth (see Table II-7), all except Long Lake support a
diverse sport fishery. In general, lake volume (area and depth) are
good predictors for estimating the total number of species of fish.
Lakes of large volume have more diverse kinds of habitat and the
potential for greater numbers of species. Despite the differences in
the years of sampling and the apparent failure to sample minnows and
other forage fishes with equal intensity in each lake, the large lakes
have more species (see Appendix E-l). Long Lake is exceptional because
68
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under certain winter conditions, its fish populations periodically are
killed by lack of oxygen. According to Mr. Don Reedstrom, the Area
Fisheries Manager, only bullheads are present in Long Lake in 1979. The
relationship between lake volume and number of species probably would be
more pronounced if the lakes were physically separated. At high water,
it is possible for fish from one lake to enter another lake.
The most sought game fishes of the Study Area include walleye,
northern pike, largemouth bass, yellow perch, bullheads, bluegills and
other sunfishes.
b. Aquatic Vegetation
Rooted aquatic vascular plants and algae, present in all lakes of
the Study Area, provide the food for hundreds of species of plant-eating
animals. Ultimately, all aquatic organisms and many terrestrial
organisms rely on the productivity of these given plants. In general,
the amount of vegetation depends on lake morphology, substrate, and
surface water quality. In the Study Area, rooted aquatic plants are
common along the shores of the shallow lakes. In deeper lakes, propor-
tionately less area is covered with aquatic vegetation. Appendix E-2
lists the dominant species of aquatic vegetation for four lakes for
which specific information is available.
In Otter Tail Lake, pockets of emergent vegetation that have formed
in several locations along the shoreline are small and often transient;
such vegetation is often destroyed by wave action or by the battering of
the shoreline by ice floes."''' Figure 11-16 shows the location and extent
of emergent vegetation. During a 1969 water quality survey the MPCA
found high counts of algae, primarily blue-green algae (Anabaena sp.,
Microcystis aeruginosa and Gleotrichia sp.)
In Lake Blanche, a 1973 DNR survey estimated that 3% of the lake
had emergent vegetation, especially along the east and south shorelines.
Submerged vegetation was scattered throughout the littoral zone. Algal
blooms were reported (DNR) for that year.
Deer Lake has a band of submerged vegetation which surrounds the
entire Lake at depths of approximately 6-13 feet. Some emergent vegeta-
tion is present on the west, south, and southeast shores. Blue-green
algae were significantly less common than in Otter Tail Lake, possibly
the result cf plankton die-off with little or no reproduction in Otter
Tail River between Otter Tail Lake and Deer Lake (DNR 1962; MPCA 1970).
On Walker Lake, the emergent vegetation is widely distributed,
especially along scattered shoal area (DNR 1962). Phytoplankton counts
were high in Walker Lake during a 1969 survey in comparison to other
lakes in the Study Area.
Round Lake appears to be the only Study Area lake with algal blooms
(DNR 1975; by letter, Mr. Donald Reedstrom, 8 June 1979). The DNR
survey estimated that 3% of the lake's area was covered with emergent
vegetation, mostly hardstem bulrushes but also including cattails and
arrowheads.
69
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c. Waterfowl
The lakes and lake marsh fringe areas of the Study Area provide
habitat for many species of nesting and migrant birds. Resident migra-
tory birds known to be breeding in the area around Otter Tail Lake
include herons, bitterns, teal, Canada geese, terns and ducks. A list
of waterfowl of the Otter Tail Lake Study Area is presented in Appendix
E-3.
2. WETLANDS
a. Overview
Wetlands are inundated by surface or groundwater with a frequency
sufficient to support aquatic or semi-aquatic life. They perform the
following important functions in the ecological and hydrological cycle:
Purify nearby surface water bodies by entrapping sediments and
concentrating nutrients which have been washed off the land-
scape.
Provide storage areas for storm and flood waters, thereby ab-
sorbing the impact of flooding.
Act as prime natural recharge areas.
Provide essential habitat for a wide diversity of wildlife,
and support biological functions such as nesting, breeding,
and feeding.
Produce plant and animal biomass* at all trophic* levels;
except for the comparably productive tropical rainforest, no
other terrestrial habitat is as rich in usable plant and
animal material.
Wetlands are sensitive to such activities as the raising or lower-
ing of the water table or altering drainage patterns.
b. Study Area
Wetlands found in the Study Area (see Figure 11-19) are associated
mainly with the lakes and streams. Unlike many of the smaller lakes
within the Study Area, extensive wetland areas have not been formed
along the Otter Tail Lake shoreline.
Otter Tail Lake. The large size and lack of protective bays of
Otter Tail Lake operate against the formation of extensive wetland
areas. The action of waves, the battering of the shoreline by ice
floes, and the expansive movement of ice reduce the likelihood that
wetlands will form on the shorelines of large lakes, such as Otter Tail.
Organic matter that has accumulated in emergent vegetation over a period
of decades may be washed away within a few hours by the recurring action
of rafted ice floes.
70
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FIGURE I1-19 WETLANDS OF THE OTTER TAIL STUDY AREA
LEGEND
* -*- .-1 WETLANDS
MILES
Source: USGS 1973
71
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Pockets of marshy areas with emergent vegetation such as bulrushes,
wild rice and arrowhead have formed in several locations along the shore
of Otter Tail Lake, but these areas are small. A few such areas are
found near the shore by Pelican Bay and along the "sand flats" of the
north shore of Otter Tail Lake, where they are mostly small patches the
size of a residential building lot. If areas such as these are able to
grow and extend toward the center of the lake, small wetlands can
develop. It is likely, however, that these incipient wetlands will be
short-lived.
Connecting Streams. There are extensive areas of emergent vegeta-
tion (bulrush and wild rice) along the connecting streams in the Study
Area. These streams are slow moving and tend to collect floating orga-
nic debris, such as fragments of vascular plants and algae.
Smaller Lakes. There are large areas of cattail wetlands associ-
ated with many of the smaller lakes in the Study Area. These wetlands
are dominated by vegetation such as cattails, sedges, arrowheads, and
grasses. The plant community dominated by cattails supports many kinds
of wildlife. Ducks, shore birds, and wading birds nest here, and feed
both in the wetlands and in the adjacent open water. Colonially-nesting
blackbirds are also seasonal residents in the cattail marshes. Muskrats
and meadow voles feed on the vegetation and a number of predators
including minks and raccoon hunt for food in these wetlands. Cattail
marshes are found in the following locations within the Study Area:
North of Deer Lake,
Adjacent to the shallow western bay of Long Lake,
Around much of the shore of Walker Lake,
Near the outlet of the Otter Tail River, and
In a low-lying area west of Amor Park on Otter Tail Lake.
This last wetland area is associated with Otter Tail Lake, but is
separated from the lake proper by a sand dike upon which cottages are
built.
Shrub wetlands containing species of alder and willow also are
present in several locations in the Study Area. A large shrub wetland
of 46.4 acres is found between Otter Tail Lake and Lake Blanche, near
Balmoral Creek. The area on the south side of Highway 78, between the
Otter Tail River outlet and Lake Blanche, contains many pockets of shrub
wetlands. One area of 126.2 acres is protected by a Federal easement
which prevents it from being drained or filled.
The wetlands associated with the smaller lakes and connecting
streams, rather than Otter Tail Lake proper, represent major areas of
environmental concern within the Otter Tail Lake Study Area.
3. TERRESTRIAL BIOLOGY
a. Forest Lands
Otter Tail County is located in the transition zone of the Northern
Forest Region and the Central Forest Region (Society of American Fore-
sters 1954). Before settlers came to the Otter Tail area, deciduous
72
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forests of maple, basswood, and oak extended to the Red River of the
North. Norway and white pine forests covered much of the northeastern
part of the Otter Tail River watershed. As a result of logging and
forest clearance for farming, the deciduous forests were reduced con-
siderably, and the pine forests were reduced to scattered stands. After
forest clearance, birch and aspen became established in the denuded
landscape (Winter, Bidwell, and Macclay 1969).
The Study Area is part prairie and part hardwood forest (Winter,
Bidwell, and Maclay 1969) of the basswood-maple type (by telephone,
Allan Olson, Minnesota DNR Regional Forester, 5 October 1978). Associ-
ated with this forest cover type are American elm, green ash, birch, red
and white oak, white pine, and hackberry (Society of American Foresters
1954).
Appendix E-4 contains list of trees found in the Otter Tail Lake
Study Area. Much of the Study Area is not forested and has been signi-
ficantly influenced by human activity such as agriculture, residential
development, and road construction. Farmlands are currently the pre-
dominant lands of the Study Area, and if allowed to return to their
natural state, the prevailing plant species would be typical of an early
successional* forest community.
b. Wildlife
A great diversity of wildlife is supported by the woodland habitat
of the Study Area. Mammals include foxes, deer, weasels, raccoons, bad-
gers, woodchucks, squirrels, gophers, mice, lemmings and voles. A com-
plete list of the mammals, birds, reptiles, and amphibians found in the
Study Area is contained in Appendix E-5.
4. THREATENED OR ENDANGERED SPECIES
The bald eagle (Haliaeetus leucocephalus), classified as "threat-
ened" by the US Fish and Wildlife Service, is a regular migratory
visitor to the Otter Tail Lake Study Area in fall and early spring (by
telephone, Carl Madson, Minnesota DNR, 2 October 1978). No nests, how-
ever, have yet been found in the Study Area. The nearest known nesting
site is located thirty miles to the north in the Tamarack Refuge (by
telephone, Dick Nores, US Department of Interior). The habitat of the
bald eagle consists of forested areas along the shores of lakes and
rivers. Trees provide nesting habitat, while lakes provide the eagle
with fish, its principal food.
The Arctic peregrine falcon (Falco perigrinus), classified as "en-
dangered" by the US Fish and Wildlife Service, has been recently
recorded in parts of Minnesota during the fall hawk migration (by tele-
phone, Carl Madson, Minnesota DNR, 2 October 1978). These birds breed
in the far north and migrate through the general vicinity of the Study
Area. No nesting sites for these birds have been identified in the
Study Area.
73
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Based on the April 30, 1979 list of the US Fish and Wildlife Ser-
vice, no other federally threatened or endangered species of plant or
animal is known to occur in Otter Tail County.
E. POPULATION AND SOCIOECQNOMICS
Existing information on population, employment, income, poverty
level and housing has been published separately for each municipal
jurisdiction in the Study Area. Together these data describe the
"Socioeconomic Study Area." The methodology used to break down this
information for the Proposed Service Area is discussed in Appendix F.
1. EXISTING POPULATION
Otter Tail County has only recently (1970 to 1975) begun to experi-
ence renewed population growth after 30 years of declining population
levels (see Table II-8). The only political subdivision of the County
which did not experience population growth during this period was Otter
Tail Village, which declined by 8.9% from 1970 to 1975. The population
increase was significant for Amor Township (19.1%), Evert Township
(22.1%) and Girard Township (15.4%) while Otter Tail Township experi-
enced a more moderate rate of growth (6.6%).
The population in the Proposed Service Area is composed of three
major elements: permanent (year-round residents); seasonal residents
(non-resident property owners); and vacation visitors housed in various
resorts, campgrounds and related tourist facilities. Summer population
was estimated using the methods described in Appendix F. As indicated
in Table II-9, the total population of 6,344 people consists of 1,094
(17.2%) permanent residents and 5,250 (82.8%) seasonal and vacation
residents.
The existing population in the Proposed Service Area is concen-
trated in Otter Tail Village, the Otter Tail Lake shoreline, the shore-
line of Blanche, Long, Walker, Deer, and Round Lakes, and along portions
of the Otter Tail River. Most seasonal residents live in the Amor,
Everts, and Otter Tail subareas; permanent residents are well distri-
buted throughout the Study Area, except for the Girard subarea, where
only 48 people reside.
The 1976 EIS population estimate differs from the Facility Plan
estimate of 6,288 persons by only 0.9%. The variation in estimates is a
result of the different occupancy rates (persons per dwelling unit) used
and the slight variations in dwelling unit equivalents assumed to exist
in each estimate.
2. POPULATION PROJECTIONS
Total and seasonal population was projected for the year 2000 for
each segment within the Proposed Service Area. In estimating the popu-
lation for the year 2000, three growth factors were considered:
74
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LOCAL UNIT
Otter Tall County
Amor Township
F.verts Township
CirnrH Township
Otter T.iii Township
Otter Tall VUl,1Rp
Table II-8
PERMANENT POPIH.ATION TRF.NnS OF THE SOCIOF.CONOMIC STUDY ARFA KOR THE PERIOD 1940-1975
1940
1950
1960
1970
1975
% OF
JPU1.ATION COUNTY
53.192 100.00
357 .67
384 .72
414 .78
206 . 79
POPULATION
51,320
413
348
164
163
1 OF
COUNTY
100.00
.80
.6R
. 70
.31
7.
CHANCE
- 3.
15.
- 9.
-12.
-20.
5
7
/,
1
9
POPULATION
48,960
366
430
296
174
% OF
COWTY
100.00
. 75
.S8
.60
. 35
CHANCE
- 4.6
-11.4
23.6
-18. 7
6. 7
POPULATION
46.097
408
429
345
212
7. OF
COUNTY
ioo.no
.89
.93
.75
.46
7.
CIIAr'GK
- 5.8
11.5
- 0.2
16.6
21.8
'/. OK ":
POPULATION COUNTY CHANCE
48,695 100. 00 Vi
486 1 .00 19. 1
524 1.08 2:>.l
398 .82 15.4
276 .46 6.6
254
.48
237
.46 -6.7
164
.31 -30.R
180
. 39
9.8
164
.34 - R.9
Sources: U.S. Census of Population, 1940, 1950, I960, 1970.
U.S. Census, Current Populntlon Reports (Series P-25), May 1977.
-------
Table II-9
EXISTING PERMANENT AND SEASONAL POPULATION
FOR THE SERVICE AREA (1976)1
TOWNSHIP OR MUNICIPALITY POPULATION PERCENT
COMPRISING SERVICE AREA
Amor
Everts
Girard
Otter Tail
Otter Tail Village
TOTAL
2,019
2,187
268
1,688
182
PERMANENT
369
222
48
303
152
SEASONAL
1,650
1,965
220
1,385
30
SEASONAL
81.7%
89.8%
82.1%
82.0%
16.5%
TOTAL SERVICE AREA 6,344 1,094 5,250 82.8%
The assumptions and methodology utilized to derive these population estimates
are found in Appendix F.
Source: WAPORA, Inc., 1978.
76
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The rate of growth or decline of the permanent population;
The rate of growth or decline of the seasonal population; and
The potential conversion of seasonal to permanent dwelling
units and the resultant effect on the permanent population;
and
Each factor was considered as being significant in the determination of
future populations and the distribution of permanent and seasonal resi-
dents within the population. Appendix F gives complete details on the
projection methodology used for this analysis.
As shown in Table 11-10 the total population for the year 2000 is
estimated to be 7,555 consisting of 1,805 (23.9%) permanent residents
and 5,750 (76.1%) seasonal residents and vacation visitors. The
projected increase in total population is 19.0% for the planning period.
The seasonal population will increase by an estimated 494 people (9.4%),
while the permanent population will increase by more than 700 people
(64.9%). In general, the population projections indicate an increasing
proportion of year-round residents in previously seasonally occupied
districts.
Of the five subareas, only Otter Tail Village will decline in
population during the planning period, while the other four subareas
will experience population growth ranging from 18.2% in Everts Township
to 22.4% in Girard Township. The percentage of seasonal residents will
also have a decrease in each of these four subareas, i.e., proportion-
ately more residents will be permanent.
3. CHARACTERISTICS OF THE POPULATION
a. Income
Based on 1970 census data, the mean income for the permanent resi-
dents of the Study Area was $6,048, a figure substantially less than the
County ($7,845), State ($11,098) and national ($10,999) figures. Girard
Township had a mean family income of only $3,077 which significantly
reduced the mean value for the Study Area (see Tabls 11-11). In com-
parision to the State and County figures, the Study Area had a larger
percentage (25.4%) of families with incomes below the Federally estab-
lished poverty level (see Table 11-12). Similar trends were observed in
1974 with per capita mean income for the Study Area 4.7% below the
County and 22.7% below the State (Table 11-11).
The relatively low incomes of the permanent population in the Study
Area largely stem from the low wage employment opportunities and to the
large retired population. Agriculture and tourism, both seasonal in
nature, are the principal industries. Approximately 40% of the Study
Area's 1970 population was over 55 years of age, compared to 20% and 19%
figures for the state and nation, respectively. This relatively high
figure is partly due to the area's attraction as a suitable place for
retirement. Many older residents have converted their seasonal homes to
77
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Table II-9
PERMANENT AND SEASONAL POPULATION OF THE OTTER TAIL LAKES
PROPOSED SERVICE AREA (2000)1
SUBAREA
Amor
Everts
Girard
Otter Tail
Otter Tail Village
TOTAL SERVICE AREA
POPULATION
PERMANENT
597
442
75
539
152
1,805
SEASONAL
1,844
2,144
252
1,480
30
5,750
TOTAL
2,441
2,586
327
2,019
182
7,555
PERCENT
SEASONAL
75.5%
82.9%
77.1%
73.3%
16.5%
76.1%
The assumptions and methodology utilized to derive these population projections
are presented in Appendix F.
Source: WAPORA, Inc., 1978.
78
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Table 11-11
MEAN AND MEDIAN FAMILY INCOME 1970,
PER CAPITA INCOME 1969 AND 1974
FAMILY
1970
MEAN
$10,999
$11,098
$ 7,845
$ 6,048
$ 6,203
$ 6,107
$ 3,077
$ 7,419
$ 7,605
1970
MEDIAN
$9,586
$9,928
$6,708
N/A
N/A
N/A
N/A
N/A
N/A
PER CAPITA
United States
Minnesota
Otter Tail County
Study Area
Amor Township
Everts Township
Girard Township
Otter Tail Township
Otter Tail Village
N/A = Not Applicable
Sources: U.S. Census of Population and Housing, Fifth Count Summary
Tapes, 1970.
U.S. Census of Population, 1970.
U.S. Census, Population Estimates and Projections, Serias P-25,
May 1977.
1969
N/A
$3,038
$2,248
$2,125
$1,960
$2,102
$1,521
$1,954
$1,774
1974
N/A
$4,675
$3,793
$3,615
$3,492
$3,324
$2,384
$3,190
$3,153
79
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Table 11-12
INCOME CHARACTERISTICS OF FAMILIES, 1970
Under $1,000
$1,000 - 1,999
$2,000 - 2,999
$3,000 - 3,999
$4,000 - 4,999
$5,000 - 5,999
$6,000 - 6,999
$7,000 - 7,999
$8,000 - 9,999
$10,000 - 14,999
$15,999 - 24,999
$25,000 - 49,000
$50,000 and over
Percent Below
Poverty Level
STATE OF
MINNESOTA
1.8
2.9
4.3
4.8
4.8
5.2
5.7
6.6
14.4
29.2
15.9
3.6
0.7
OTTER TAIL
COUNTY
3.6
6.5
8.9
8.8
7.8
0.6
8.2
6.8
13.4
18.0
7.5
1.7
.2
STUDY AREA
6.7
11.0
14.6
9.6
5.8
9.6
13.2
3.4
9.8
10.3
5.9
-0-
-0-
8.2%
16.6%
25.4%
Sources: U.S. Census, General Social and Economic Characteristics, 1970.
U.S. Census, Census of Population and Housing, Fifth Count Summary
Tapes, 1970.
80
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permanent use upon retirement. Because elderly and retired families
often live on limited or fixed incomes, it is not surprising that 42.2%
of all persons of poverty status were 65 years of age or older.
No published statistics on socioeconomic characteristics of the
seasonal population are available for either the Study Area or Otter
Tail County. In general, the seasonal population has a relatively
higher mean family income which allows them to own and maintain a per-
manent as well as a seasonal home. Compared to the relatively low
family incomes of permanent residents in the Study Area, it is nearly
certain that seasonal residents have substantially higher family
incomes.
Past trends regarding seasonal residents indicate that the majority
are married couples with families. However, recent indications point
toward more singles and married couples without children purchasing
second homes, resulting in smaller seasonal resident occupancy rates
(persons per unit).
Generally, the higher incomes of seasonal residents allow them to
be relatively mobile. As a result, it is difficult to determine whether
their seasonal residences could be their likely place of retirement.
However, discussions with local sources knowledgable about the area
indicate that the permanent population includes many retirees, a large
portion of which converted their seasonal dwelling for permanent use.
b. Employment
During 1970, nearly three-fourths of all employed Otter Tail County
residents were engaged in agriculture, services, or trade. Agriculture
and services accounted for more than 25% each of the County's total
employment, and trade accounted for an additional 21%. Only 9.2% of
Otter Tail County's residents were employed in manufacturing activities
(see Table 11-13).
Tourism and travel-related activities make up a large part of the
County's retail trade and service activity based on 1970 data. Hotels
and amusement services accounted for over 60% of Otter Tail County
service industry receipts compared to only 22% for Minnesota. Retail
trade statistics for 1972 reinforce the observation that travel-related
industries are important to the Otter Tail County economy. Sales from
gasoline service stations were substantially higher on a percentage
basis than the figures for the State, suggesting a high seasonal con-
sumption of gasoline by tourists.
c. Financial Characteristics
Table 11-14 describes financial characteristics for the local
governments in the Study Area. This information is necessary for the
evaluation of various alternatives available to the local governments
for financing wastewater management improvements.
In Minnesota, counties serve as agents for subordinate government
units, acting as the collector and distributor Dt" taxes and grants.
Revenues are generated by three major sources:
81
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Table 11-13
PERCENTAGE EMPLOYMENT BY MAJOR INDUSTRY - 1970
STATE
MINNESOTA
REGION IV
OTTER TAIL
COUNTY
Agriculture
Mining
Construction
Manufacturing
Transportation
Utilities and
Communication
Trade
Finance
Service
Government
7.7%
1.0%
5.7%
21.0%
6.6%
22.0%
4.6%
27.6%
3.8%
100.0%
20.2%
0.1%
6.1%
7.7%
6.6%
22.7%
3.6%
29.4%
3.6%
100.0%
25.2%
0.1%
5.5%
9.2%
6.7%
21.0%
2.4%
26.8%
3.1%
100.0%
Source: U.S. Department of Commerce, 1970 U.S. Census of Population, 1970
Minnesota General Social & Economic Characteristics.
82
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Table 11-14
FINANCIAL CHARACTERISTICS OF THE LOCAL
GOVERNMENTS IN THE OTTER TAIL LAKE STUDY AREA
CO
Taxable
Valuation
Total
Revenue
Receipts
Total
Current
Expense
Total
Capital
Outlay
OTTER TAIJ/ '
COUNTY
$103,167,666
7,215,514
5,124,700
2,641,934
AMORV '
TOWNSHIP
$1,877,084
31,519
33,171
5,815
EVERTS k '
TOWNSHIP
$2,263,611
22,825
18,239
25,362
GIRARCT ;
TOWNSHIP
$1,610,968
23,819
19,083
5,435
OTTER TAH/ '
TOWNSHIP
$1,315,048
19,657
10,087
219
OTTER TAIL
TOWNSHIP
$572,345
20,124
11,140
(3)
Total
Indebtedness
315,000
Sources: (1) Report of the State Auditor of Minnesota, Revenues, Expenditures and Debt of Local Governments
in Minnesota, August, 1977.
(2) Report of the State Auditor of Minnesota, Revenues, Expenditures and Debt of the Towns of
Minnesota, January, 1978.
(3) Report of the State Auditor of Minnesota, Revenues, Expenditures and Debt of Cities in
Minnesota, November, 1977.
-------
General property tax,
Federal revenue sharing, and
State aid to local governments, usually $25-$30 per capita.
From these revenues, expenditures for general government and capi-
tal are made. Counties, townships and cities all can incur debt in the
form of general obligation bonds. The debt limit on such bonds is set
at 6-2/3% of the taxable valuation of the governmental unit. General
obligation bonds require voter approval in Minnesota. In contrast,
revenue bonds have no set debt limit and do not require a public
referendum.
According to Table 11-14, only Otter Tail County had any out-
standing debt at the end of fiscal year 1975, a $315,000 debt in the
form of revenue bonds. As a result, it appears that all of the local
governments are in sound fiscal condition to finance future wastewater
management improvements.
4. HOUSING CHARACTERISTICS
Existing dwelling units for each segment within the Proposed
Service Area were determined using aerial photographs and local records.
The total number of dwelling unit equivalents in 1976 was 1440, con-
sisting of 390 (27.1%) permanent units and 1,050 (72.9%) seasonal units
(see Table 11-15). Almost all of the dwellings are single-family units,
including the approximately 160 resort units. All units are served by
on-site wastewater disposal systems.
Age characteristics of the housing stock for 1970 indicate that the
Study Area had proportionately fewer units built before 1939 (38.2%)
than either the State (49.4%) or the County (61.0%). In fact, nearly
20% of the Study Area's housing stock was, built after 1965, including
27.4% in Amor Township and 20.9% in Girard Township. Of the five sub-
areas, only Otter Tail Village was characterized by a relatively old
housing stock.
The 1970 median value of owner-occupied units in the County and
presumably in the Study Area as well ($11,987) was considerably lower
than the State ($18,054) and national ($17,130) figures. This can be
attributed in part to the large number of seasonal units which have been
converted to permanent homes. Although no specific information regard-
ing the characteristics of seasonal dwelling units is available, as
part-time residences they are presumably generally smaller in size,
lower in value, and lacking many of the amenities of permanent units.
Consequently, when seasonal units are converted to permanent use, they
depress the value of the permanent housing stock.
5. LAND USE
a. Existing Land Use
The primary land use categories in the Study Area include agri-
culture, forests, lakes and wetlands. Figure 11-20 shows the extent of
these land use categories. Urban development, mostly in the form of
-------
Table 11-15
EXISTING DWELLING UNITS
IN THE OTTER TAIL PROPOSED SERVICE AREA
TOWNSHIP OR MUNICIPALITY
COMPRISING SERVICE AREA TOTAL PERMANENT SEASONAL
Amor 453 123 330
Everts 467 74 393
Girard 60 16 44
Otter Tail 378 101 277
Otter Tail Village 82 76 6
TOTAL 1,440 390 1,050
*Includes Resort facilities
Source: WAPORA, Inc., 1978.
85
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FIGURE TI-20 EXISTJ.NG LAND USE IN THE OTTER TAIL STUDY AREA
LEGEND
J RESIDENTIAL
^| FOREST AND WETLAKDS
ACRICULTU11AL AND OP UN PASTU11ELAND
WILDLIFE MANAGE2-n-NT AND CAME AREAS
MILES
^OT,f COURSE
I.TC ACCESS
86
Source: USGS 1973;
Otter Tail County
Planning Advisory
Comtnission 1968
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single family residential land use, has been confined to areas around
the various lakeshores and Otter Tail Village. Lakeshore development is
in a single tier pattern for the most part. The most densely populated
lakeshore areas include: most of the Otter Tail Lake shoreline, the
north shore of Lake Blanche, the south shores of Walker Lake and Long
Lake, Round Lake and the north shore of Deer Lake. Many of the lots
around Otter Lake are small with about 40-50% being less than 20,000
square feet. The extent and distribution of lot sizes is shown in
Figure 11-18.
b. Future Land Use/Growth Management
Otter Tail County has no comprehensive land use plan. The primary
sources of growth management capabilities influencing development
activity within the Proposed Service Area are the local township zoning
ordinances and the Otter Tail County Shoreland Management Ordinance. Of
the four townships located in the Study Area, only Amor Township has no
zoning ordinance. Development restrictions imposed by the Shoreland
Management Ordinance are incorporated into the local township
ordinances. Land areas situated within 1,000 feet of the normal high
water mark of any inland lake (300 feet from a river or stream) have
been designated shoreland management districts. Single-family resi-
dences and agriculture are the permitted uses in the shoreland
management district. Additional uses are allowed upon issuance of a
special use permit by the Planning Advisory Commission.
Conditional uses vary with lake classification. All lakes have
been classified as either "Natural Environment", "Recreational Develop-
ment", or "General Development" areas. Otter Tail Lake is classified as
a General Development Lake while the small surrounding lakes are classi-
fied as Recreational Development Lakes.
The minimum shoreland development standards for residential homes
vary with the lake classification (see Table 11-16).
Parks or resort facilities are conditional uses permitted along
Natural Environment or Recreational Development shoreline. Churches may
obtain special use permits in Recreational or General Development areas.
Industrial development, if properly screened from public rights-of-way,
is conditionally permitted in General Development areas.
Specific provisions for sanitation standards, shoreland altera-
tions, non-conforming uses, cluster development, and special exemptions
are established in the Shoreland Management Ordinance. Detailed regula-
tions governing the development of mobile home parks, recreational camp-
grounds, resorts, and controlled accesses are also provided.
Cluster developments and resorts, subject to official review and
approval, may be developed at one fourth of the minimum lot sizes and
lake frontage required per dwelling unit. These special dispensations
depend upon provision of central sewage facilities which meet State
health and pollution control standards and upon the preservation of open
space. Dedication of open space to community use moderates the overall
37
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Table 11-16
MINIMUM SHORELAND ORDINANCE STANDARDS
WATER BUILDING SETBACK
LAKE CLASSIFICATION LOT AREA FRONTAGE FROM SHORELAND
Natural
Environment (NE) 80,000 sq. ft. 200 ft. 200 ft.
Recreational
Development (RD) 40,000 sq. ft. 150 ft. 100 ft.
General
Development (GD) 20,000 sq. ft. 100 ft. 75 ft,
Source: Otter Tail County Shoreland Management Ordinance, 1973.
88
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intensity of site development, while allowing developers to take advan-
tage of economies of scale in residential construction and provision of
services. For a given level of development, clustered development often
tends to minimize associated adverse environmental consequences.
Residential densities of up to two dwelling units per acre are
possible for future development around Otter Tail Lake, while maximum
densities are limited to one dwelling per acre around Blanche, Long,
Walker, Deer, and Round Lakes. Clustered residential or resort develop-
ment is possible at densities of up to eight or nine dwellings units per
acre around Otter Tail Lake and up to four dwellings per acre around the
other lakes.
c. Recreation
A prime attraction of the Otter Tail Lakes area is its recreational
potential. Major activities include boating, fishing, camping, and
swimming. No figures are available to indicate the relative amount of
usage each water body in the Study Area receives. However, the large
number of seasonal residences and the many public lake access points in
the Study Area indicate extensive recreational usage of the lakes.
Public Waysides. There are several wayside rest and historical
sites in the Study Area maintained by the Minnesota Highway Department.
Generally, the wayside rest areas provide picnicking and basic sanitary
facilities for passing motorists, while historic areas are maintained
for the designation of a natural or man-made point of significance.
Public Lake Access. Public access to the lakes in the Study Area
is provided at thirteen locations as depicted in Figure 11-23. The
largest lake (Otter Tail) has a total of 24.4 miles of shoreline with
several areas available for public access (see Table 11-17). The five
other major lakes in the Study Area have no more than one public access
point.
Wildlife Areas. Several wildlife management areas operated by the
Minnesota Department of Conservation are located in the Study Area (see
Figure 11-20).
Campgrounds. Five campgrounds exist around the lakes in the Otter
Tail Lake Study Area. The major characteristics of these private camp-
grounds are indicated in Table 11-18.
d. Transportation
Major transportation networks into the area include Routes 74 and
108 which run east-west and Route 78 which runs north-south. Figure
11-20 shows the location of major roads and highways within the Study
Area. Rail transportation is provided by both the SOO Railroad and the
Burlington Northern Line.
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Table 11-17
PUBLIC ACCESS TO LAKES IN THE
OTTER TAIL STUDY AREA
MUNICIPALITY
Townships of
Amor, Everts,
Otter Tail
Townships of
Amor, Everts
Otter Tail
Townships of
Amor, Everts
Otter Tail
Townships of
Everts and
Girard
Everts Township
Amor Township
Everts Township
Amor Township
Amor Township
Amor Township
LAKE
Otter Tail Lake
Otter Tail Lake
Otter Tail Lake
Lake Blanche
Deer Lake
Long Lake
Round Lake
Walker Lake
Brown Lake
Twin Lakes
SHORE MILES
24.4
24.4
24.4
5.4
3.8
9.0
2.0
3.7
FACILITY
5 Public Access Points
4 Wayside Parks
3-Recreation Parks
Public Access Point
Public Access Point
None
None
Public Access Point
Public Access Point
Public Access Point
Sources: Telephone interview with staff of Otter Tail County Department of
Land and Resource Management, 3/14/78.
"Minnesota Lake Shore" Summary Report of the Minnesota Development
Study, 1970.
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Table 11-18
PRIVATE CAMPGROUNDS LOCATED IN THE OTTER TAIL LAKE
STUDY AREA
NAME
Beachwood
Otter Tail Lake
Riverside
Wheel-In
Wildwood
TOTAL
ACREAGE
TENT SITES
TRAILER SITES
3.0
20.0
4.0
4.5
1.5
33.0
9
40
15
30
4
98
9
6
4
19
LOCATION
Battle Lake
Otter Tail Lake
Otter Tail Lake
Battle Lake
Otter Tail Lake
Source: Otter Tail County Planning Advisory Commission, 1968.
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5. CULTURAL RESOURCES
a. Archaeological Resources
During the preparation of this EIS, the Minnesota Historical Soci-
ety and the Otter Tail County Historical Society were contacted concern-
ing the location of cultural resources in the Study Area. The Facility
Plan's Proposed Action has been reviewed pursuant to the responsibil-
ities given the State Historic Preservation Officer by the National
Historic Preservation Act of 1966. Currently, the Minnesota Historical
Society is conducting a comprehensive statewide survey of archaeological
and historical sites, but Otter Tail County has not yet been surveyed.
Systematic surveys conducted throughout the state have shown a high
correlation between prehistoric sites and permanent natural water
sources, such as lakes and rivers. Because of this, the Society recom-
mends that undisturbed or minimally disturbed areas within 1,000 feet of
natural shoreline (which would be affected by the construction of sewage
treatment facilities) be examined for prehistoric archaeological sites
(by letter, Russell W. Fridley, State Historic Preservation Officer, 3
April 1978).
The Otter Tail County Historical Society identified artifacts and
eleven burial sites located in the Study Area, six of which are within
the immediate Facility Planning Area. The precise locations of these
sites are confidential. The Morrison Mounds Historical Site, which is
publicly known, is located just south of Otter Tail Lake in Everts
Township at SW 1/4, SW 1/4, Sec. 4, T133, R40 (see Figure 11-21). This
archaeological site is listed with the National Register of Historic
Places.
Investigations conducted by Dr. Michael Michlovic of Moorhead
(Minnesota) State University at a site near the Dead River inlet to
Otter Tail Lake, produced an abundance of prehistoric artifacts, most of
which related to the Blackduck culture dated to A.D. 885. This dis-
covery is significant because it had been thought that the Blackduck
people had not extended so far south, but remained in northern Minnesota
and Canada. According to Dr. Michlovic, further findings may reinforce
the hypothesis that there was a band of territory across central Minne-
sota, covered with woodland and prairie that was highly contested among
prehistoric cultures (Fergus Falls Daily Journal, 28 February 1978).
Dr. Michlovic is of the opinion that the Otter Tail Lake region is quite
rich archaeologically, and that large scale land disturbance activities
would certainly endanger more than a few valuable cultural sites (by
letter, Dr. Michael Michlovic, Assistant Professor of Anthropology, 16
June 1978) (see Appendix G).
Upon the selection of a final alternative, detailed designs and
specifications will be sent to the State Historic Preservation Officer.
At that time, detailed site investigations will be performed by an
archaeologist to resolve potential conflicts with any archaeological
site which could be disturbed by construction activities.
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FIGURE 11-21 ARCHAEOLOGICAL AND HISTORICAL SITES IN
THE OTTER TAIL STUDY AREA
ARCHAEOLOGICAL SITES
A MORRISON HOUNDS
HISTORICAL SITES
B OLD OTTERTAIL CITY
C ST. PAUL HOUSE
D CRAIGE GRIST HOUSE
93
MILES
Source: By letter, Dick
Lee, Otter Tail County
Historical Society,
20 June 1978
-------
b. Historical Resources
The Minnesota Historical Society has listed two sites in the Otter
Tail Lake Study Area as having local historical significance (by letter,
Russell W. Fridley, State Historic Preservation Officer, 3 April 1978).
Locations of the Craigie Flour Mill (NE 1/4, SE 1/4, Sec. 31, T134N,
R39W) and the St. Paul House (Lot 4, Sec. 10, Otter Tail Township) are
shown in Figure 11-21. The Otter Tail County Historical Society has
also identified remnants of the original Ottertail City as a historical
site. This boomtown of the late nineteenth century was the original
county seat of Otter Tail County until a Mr. Thomas Cathcart refused to
give a right-of-way through his property to the Northern Pacific Rail-
road Company. The company consequently changed its routing plans,
whereupon the county seat was moved to Fergus Falls. Ottertail City
lost residents until 1885, when nothing but a farm remained. The pres-
ent Ottertail City, 1 mile east of the original, dates from 1903.
Upon the selection of a final alternative, designs and specifica-
tions will be sent to the State Historic Preservation Officer to avoid
any disturbance of historic sites.
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CHAPTER III
DEVELOPMENT OF ALTERNATIVES
A. INTRODUCTION
1. GENERAL APPROACH
New alternative approaches for wastewater collection and treatment
in the Proposed Otter Tail Lake Service Area are developed in this
chapter. In Chapter IV, the alternatives are described and compared in
terms of cost-effectiveness with the Proposed Action in the Facility
Plan Report (Ulteig Engineers Inc. 1976). Chapter V assesses the
environmental and socioeconomic impacts of each alternative.
New EIS alternative development focuses on those aspects and
implications of the proposed wastewater management plan for the Service
Area which either have been identified as major issues or concerns, or
were not adequately addressed in the Facility Plan. The high cost of
the Facility Plan Proposed Action and the potential impact on area
residents make the cost-effectiveness of proposed facilities a major
concern. Since the collection system accounts for approximately 83% of
the Proposed Action cost, the extent of servicing necessary, along with
alternative wastewater treatment systems and the use of newer
technologies for wastewater collection are investigated in detail. The
development of alternative treatment facilities has been undertaken by
matching available technologies, both conventional and alternative or
innovative, to site conditions such as soil characteristics and housing
density in the Proposed Service Area.
Chapter I of this EIS emphasized the importance of the overall need
for the project proposed in the Facility Plan. Documenting a clear need
for new sewered wastewater facilities is difficult, requiring evidence
that the existing on-lot systems are directly related to water quality
and public health problems. Such a need is shown when one or more of the
following conditions exist:
Standing pools of septic tank effluent or raw domestic sewage
in yards or public areas where direct contact with residents
is likely.
Sev-a^e in basements from inoperable or sluggish sewage
disposal systems.
Contaminated private wells clearly associated with sewage
disposal systems.
The Proposed Service Area exhibits some indirect evidence of the
unsuitability of site conditions for on-site soil disposal systems. The
evidence includes high groundwater, high groundwater flow rates, small
lot sizes, proximity to lakeshores and substandard setback distances
between wells and on-site wastewater facilities. Available information
95
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on these factors was used early in the preparation of this EIS to
develop the decentralized alternatives designated EIS Alternatives 1, 2,
and 3.
Indirect evidence alone cannot justify Federal funding, however.
Federal water pollution control legislation and regulations require
documentation of actual water quality or public health problems.
Section II.C. summarizes the efforts mounted during the preparation of
this EIS to document and quantify the need for improved facilities
around Otter Tail Lake.
The dollar cost of the Facility Plan Proposed Action and its impact
on area residents make cost-effectiveness an issue as important as needs
documentation. Since the collection system accounts for the major share
of the construction costs in the Facility Plan Proposed Action, the
necessity of sewers and possible use of other technologies for
wastewater collection have been investigated in detail here, as have
alternative wastewater treatment systems. The technologies assessed are
listed below:
WASTEWATER MANAGEMENT COMPONENTS AND OPTIONS
Functional Component
Flow and Waste Load
Reduction
Collection of Wastewaters
Options
Wastewater Treatment
Processes
Effluent Disposal
Sludge Handling
Sludge Disposal
household water conserva-
tion measures
ban on phosphorus
limited service area
pressure sewers
vacuum sewers
gravity sewers
conventional centralized
treatment plus chemical
treatment to reduce
phosphorus concentrations
land Application
on-site treatment
cluster systems
subsurface disposal
land application
discharge to surface
waters
anaerobic digestion
dewatering
land application
landfilling
composting
contract hauling
96
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Next, appropriate options were selected and combined into the
alternative systems described in Chapter IV. The last section of
Chapter III considers implementation, administration and financing of
the alternatives.
2. COMPARABILITY OF ALTERNATIVES: DESIGN POPULATION
The various alternatives for wastewater management in the Proposed
Service Area must provide equivalent levels of service if their designs
and costs are to be properly compared. A design population of 7,555 has
been assumed (see Section II.E.I) in the following evaluation of
alternatives. The design population is that population projected to
reside in the Proposed Service Area in the year 2000. The methodology
used to develop this estimate is presented in Appendix F.
For just comparison, all EIS alternatives and the Facility Plan
Proposed Action are based on the same year 2000 population; note
however, that each alternative carries its own constraints and that the
wastewater management system chosen may itself significantly shape the
Proposed Service Area's actual year 2000 population.
3. COMPARABILITY OF ALTERNATIVES: FLOW AND WASTE
LOAD PROJECTIONS
Design flows for centralized treatment facilities and for the
cluster systems are based on a design domestic sewage flow of 60 gallons
per capita per day (gpcd) in residential areas for both permanent and
seasonal residents. Infiltration and inflow"' (I/I) into gravity sewers
was added to the calculated sewage flow in appropriate alternatives.
Table III-l summarizes these data.
To maintain comparability of alternatives for costing purpose the
following modifications were made in the Facility Plan Proposed Action:
The design flow used in the Facility Plan was 65 gpcd
including I/I. The flows developed for this EIS were used to
recalculate flows for the Proposed Action; that is, design
flows were based on 60 gpcd not including I/I.
The Facility Plan's population projections differed somewhat
from those developed for this EIS. The new population
projections were used to recalculate total flows.
The Facility Plan recommended a pressure sewer collection
system using grinder pumps in low-lying areas . Effluent
pumps for septic tank effluent replaced grinder pumps.
Section II.B.2 discusses the advantage of this.
The domestic sewage generation rate depends upon the mix of
residential, commercial, and institutional sources in the area. Studies
on residential water usage (Witt, Siegrist, and Boyle 1974; Bailey et
al. 1969; Cohen and Wallman 1976) reported individual household water
consumptions varying widely between 20 and ICC gpcd. However, averaged
97
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Table III-l
EIS ALTERNATIVE 1
Total Flow = 0.114 ragd
Infiltration/Inflow = 0.009 mgd
0.123 mgd
Winter Flow = 0.017 mgd
Infiltration/Inflow = 0.009 mgd
O.Q26 mgd
EIS ALTERNATIVE 2
Total Flow = 0.264 mgd
Infiltration/Inflow = 0.039 mgd
0.303 mgd
Winter Flow = 0.037 mgd
Infiltration/Inflow = 0.039 mgd
0.076 mgd
EIS ALTERNATIVE 3
Total Flow = 0.378 mgd
Infiltration/Inflow = 0.036 mgd
0.414 mgd
Winter Flow = 0.066 mgd
Infiltration/Inflow = 0.036 mgd
0.102 mgd
EIS ALTERNATIVES 4, 5, AND
FACILITY PLAN PROPOSED ACTION
Total Flow = 0.456 mgd
Infiltration/Inflow = 0.047 mgd
0.503 mgd
Winter Flow = 0.085 mgd
Infiltration/Inflow = 0.047 mgd
0.132 mgd
98
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values reported in those studies generally ranged between 40 and 56
gpcd. On a community-wide basis, non-residential domestic (commercial,
small industrial, and institutional) water use increases per capita
flows. The extents of such increases are influenced by:
the importance of the community as a local or regional trading
center;
the concentration of such water-intensive institutions as
schools and hospitals; and
the level of small industrial development.
For communities with populations of less than 5,000, EPA regulations
allow design flows in the range of 60 to 70 gpcd where existing per
capita flow data is not available. In larger communities, and in
communities within Standard Metropolitan Statistical Areas, the maximum
allowable flow ranges up to 85 gpcd.
Water consumption by seasonal users varies much more than
consumption by permanent residents. The actual consumption rates depend
upon such factors as type of accommodations and the recreation areas
available. EPA regulations (EPA 1978) suggest that seasonal population
be converted to equivalent permanent population by using the following
multipliers:
Day-use visitor 0.1 to 0.2
Seasonal visitor 0.5 to 0.8
A multiplier of 1.0 was applied to the projected seasonal
population to account for both day-use and seasonal visitors.
Considering the possible error in projecting future seasonal
populations, the preponderance of present seasonal visitors using
well-equipped private dwellings, and the lack of data on day-use
visitors, this multiplier is conservative, probably overestimating flows
to some degree.
The design flow figure of 60 gpcd does not reflect reductions in
flow from a program of water conservation. Residential water
conservation devices, discussed in Section III.B.I.a, could reduce flows
by 16 gpcd. To demonstrate probable impacts of such reduction in flow,
the Facility Plan Proposed Action was redesigned and recosted with flow
reduction measures.
B. COMPONENTS AND OPTIONS
1. FLOW AND WASTE REDUCTION
a. Residential Flow Reduction Devices
There are many devices to reduce water consumption and sewage flow.
A list of some of them is presented in Appendix H-l with data on their
99
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water saving potential and costs. Most of these devices will require no
change in the user's habits and are as maintenance-free as standard
fixtures. Others, such as compost toilets, may require changes in
hygiene practices and/or increased maintenance. The use of any of these
devices may be justified under certain conditions, as when no other
device can provide adequate sanitation or when excessive flows cause
malfunctions of conventional on-site septic systems. Usually, however,
the justifications for flow reduction devices are economic.
Table III-2 list proven flow reduction devices and homeowner's
savings resulting from their use. These estimates were made using data
on the devices listed in Appendix H-2 and local cost assumptions listed
beneath the table. The homeowner's savings include savings for water
supply, water heating and wastewater treatment. A combination of a
shower flow control insert device, dual cycle toilet and lavatory faucet
flow control device would save approximately $71/household/year.
Should all residences in the Proposed EIS Service Area install
these devices, not all could save the $1.40/1000 gallons in wastewater
treatment costs unless the facilities were designed for the reduced flow
(see assumption in Table III-2). This is because much of this charge
goes to pay off capital, operation and maintenance costs which will
remain constant even at reduced flow. For all to benefit fully from
flow reduction, wastewater collection, treatment and disposal facilities
would have to be designed with capacities reflecting the lower sewage
flows. Use of the three types of devices cited above would reduce per
capita sewage flows by approximately 12 gpcd. To calculate the
cost-effectiveness of community-wide flow reduction, the Facility Plan
Proposed Action (see Section IV.B.2) was redesigned and recosted using a
design flow based on 44 gpcd instead of 60 gpcd.
The estimated savings in project capital cost (1980) would be
$758,000 and the operation and maintenance cost savings would be ap-
proximately $7,000 per year. To achieve this savings, approximately
$9,000 worth of flow reduction devices would be necessary. The total
present worth* of savings over the 20-year design period would be
$738,000 or approximately 7% of the Facility Plan Proposed Action.
These economic analyses of homeowner's saving and total present
worth reduction assume sewering of all dwellings. However, for
dwellings continuing to use on-site systems the economic benefits of
flow reduction cannot be readily estimated. State regulatory agencies
generally do not allow a reduction in the design of conventional on-site
systems based upon proposals to use flow reduction devices. However, it
is likely that reduced flows will prolong the life of soil absorption
systems thereby saving money in the long run.
Some decentralized technologies may need substantial flow
reductions regardless of costs. Holding tanks, soil absorption systems
which cannot be enlarged, evaporation or evapotranspiration systems, and
sand mounds are examples of technologies offering less risk of
malfunction with minimal sewage flows. Flows on the order of 15 to 30
gpcd can be achieved by installation of combinations of the following
devices:
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Table II1-2
ESTIMATED SAVINGS WITH FLOW REDUCTION DEVICES
Shower flow control insert device
a
Dual cycle toilet
Toilet damming device
Shallow trap toilet3
Dual flush adapter for toilets
Spray tap faucet
Improved ballcock assembly for toilets
Faucet flow control device
Faucet aerator
First Year
Savings
(or Cost)
$32. 44
15.23
14.36
12.61
10.68
(78.59)
8.74
5.72
1.13
Annual Savings
After First
Year
$34.44
35.23
17.61
17.61
14.68
8.61
11.74
8.72
3.63
First year expenditure assumed to be difference in capital cost between
flow-saving toilet and a standard toilet costing $ T5
Assumptions
Household:
Water Cost:
Water Heating
Cost:
Wastewater
Cost:
Four persons occupying dwelling 328 days per year. One
bathroom in dwelling.
Private well water supply. Cost of water = $0.02/1000
gallons for electricity to pump against a 100 foot hydraulic
head.
Electric water heater. Water temperature increase = 100°F.
Electricity costs $0.03/kilowatt-hour. Cost cf water
heating = $7.50/100 gallons.
Assumed that water supply is metered and sewage bill is
based on water supply at a constant rate of $1.77/1000
gallons. Rate is based on a 1980 Study Area sewage flow
of 0.4 tngd and local costs of $46,200 in 1980 for the
Facilities Plan Proposed Action as estimated in this EIS,
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Spray tap faucets to reduce lavatory water usage.
Dual cycle or other low volume toilets replacing standard
toilets.
Thermostatic mixing valves and flow control shower heads to
reduce shower water use. Use of showers rather than baths
should be encouraged whenever possible.
Front-loading machines or others with water level controls to
replace older clothes washing machines.
Use of in-house composting toilets to replace water-carried
toilets.
Recycle bath and laundry wastewaters for toilet flushing.
Filtering and disinfection of bath and laundry wastes for this
purpose has been shown to be feasible and aesthetically
acceptable in pilot studies (Cohen and Wallman 1974;
Mclaughlin 1968). This alternative to composting toilets that
achieve the same level of wastewater flow reduction.
Recycle bath and laundry wastewaters for lawn sprinkling in
summer. The feasibility of this method would have to be
evaluated on a trial basis in the Study Area because its
general applicability is not certain.
Commercially available pressurized toilets and air-assisted
shower heads using a common air compressor of small horsepower
would reduce sewage volume from these two largest household
sources up to 90%.
The Microphor pressurized, low flush toilet has been considered in
detail in this EIS. The flushing cycle for the low flush toilet is air
operated and is activated by a flush handle. During the flush cycle
waste material flows into an evacuation chamber. Air pressure is
introduced, discharging the waste into the sewer line. Whereas
conventional toilets use from 5 to 7 gallons of water during a typical
flush cycle, the low flush toilet uses only 2 quarts. Substitution of
the conventional toilet for the low flush toilet would result in a
reduction of total residential water use by about 40%. This amounts to
a savings in water costs of $6.30/yr. The low flush toilet would
require no changes in user's habits and could be an important factor in
reducing sewage disposal problems for the area. Human wastes would be
discharged from the toilet into a holding tank. The frequency of
holding tank pumping, would be significantly reduced by the use of low
flush toilets.
b. Minnesota Ban on Phosphorus
Phosphorus is frequently the nutrient controlling algae growth in
surface waters and is therefore an important influence on lake or stream
eutrophication. Nutrient enrichment of the waters encourages the growth
of algae and other microscopic plant life; decay of the plants increases
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biochemical oxygen demand, decreasing dissolved oxygen in the water.
Addition of nutrients also encourages higher forms of plant life,
hastening the aging process by which a lake evolves into a bog or marsh.
Normally, eutrophication is a natural process proceeding slowly over
thousands of years. Human activity however, can greatly accelerate it.
Phosphorus and other nutrients, contributed to surface waters by human
wastes, laundry detergents and agricultural runoff, often result in
over-fertilization, over-productivity of plant matter, and "choking" of
a body of water within a few years. Appendix C-5 discusses the process
and data pertinent for the Otter Tail Lake Study Area.
In 1977 the Minnesota legislature limited the amount of phosphorus
in laundry and cleaning supplies sold in the state to 0.5%. Presently,
there is no enforcement of this law because an injunction has been
issued as a result of a lawsuit.
The Minnesota Pollution Control Agency estimates that for the
Minneapolis-St. Paul area (where a local phosphorus ban is in effect) a
35% reduction in phosphorus loading in raw wastewater effluent has
resulted. The Twin Cities have experienced a 1.1 pound per capita per
year reduction in phosphorus loading from 1971 to 1974 (by telephone,
Craig Affeldt, MPCA, April 1978).
Treatment plants and on-site disposal facilities in the Study Area
could experience a similar reduction in phosphorus concentration.
However, reduction of phosphorus by control of detergents will not
achieve the effluent discharge limits of 1 mg/1 (see Appendix C-6 for
Effluent Limits) for discharges to area lakes or their tributaries.
Consequently, facilities for phosphorus removal are required in
treatment plants which discharge to any of the surface water bodies in
the Study Area. A phosphorus ban would result in an unquantifiable
reduction in phosphorus entering surface waters with septic tank
leachate.
2. COLLECTION
The collection system for the Facility Plan Proposed Action is
estimated to cost $8.6 million or 83% of the total cost. Since not all
parts of collection systems are eligible for Federal and State funding,
the collection system costs can affect the local community more than
other components of the project. There is, therefore, considerable
incentive at local, state and national levels to choose less expensive
alternatives to conventional sewer systems
Alternative means of wastewater collection are:
pressure sewers (including grinder pumps or STEP systems);
vacuum sewers; and
» small diameter gravity sewers (Troyan and Norris 1974).
An alternative collection system may more economically sewer areas
with site conditions that increase the cost of conventional sewerage,
such as shallow depth to bedrock, high groundwater table, or hilly
terrain. Housing density also affects the relative costs of
conventional and alternative wastewater collection techniques.
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The alternative collection method receiving the most attention is
sewage pumping by the use of a low-pressure sewer systems. The pressure
sewer system is the reverse of a water distribution system. The water
system consists of a single inlet pressurization point and a number of
user outlets, while the pressure sewer system has a number of
pressurizing inlet points and a single outlet. Inputs to the pressure
main generally follow a direct route to the treatment facility or to a
gravity sewer.
The two major types of pressure sewer systems are the grinder pump
(GP) system and the septic tank effluent pumping (STEP) system. The
differences between the two systems are in the on-site equipment and
layout. The GP system employs individual grinder pumps to convey raw
wastewater to the pressure sewer. In the STEP system septic tank
effluent from individual households is pumped to the pressure main. The
pressure sewer design is basically the same for either STEP or grinder
pumps. The advantages of pressure sewer systems are:
0 elimination of infiltration/inflow;
reduction of construction cost; and
use in varied site and climatic conditions.
The disadvantages include higher operation and maintenance cost, and the
requirement for individual home STEP systems or grinder pumps.
Vacuum sewers provide similar advantages. Their major components
are vacuum mains, collection tanks and vacuum pumps, and individual home
valve connection systems. A recent review of vacuum sewer technology,
however, noted significant differences among design of four major types
of current systems (Cooper and Rezek 1975).
As a third alternative to conventional gravity sewers, small
diameter (4-inch) pipe can be used if septic tank effluent, rather than
raw waste, is collected. Such pipe may result in lower costs of
materials, but the systems retain some of the disadvantages of larger
sewers. The need for deep excavations and pump stations is unaffected.
Preliminary design studies for otner lake projects suggest that the
use of small diameter gravity sewers may become cost preferable to
pressure sewers at shoreline housing densities greater than 50 homes per
mile.
A comparison of the costs of STEP and grinder pump types of low
pressure sever systems indicated that the STEP system would be
cost-effective by a slight margin. An important assumption in this
analysis was that 5070 of the existing septic tanks would need to be
replaced for use in the STEP system. STEP low pressure systems are used
in the development of all EIS alternatives. The Facility Plan Proposed
Action has also been modified by the replacement of grinder pumps with
STEP systems. The decision in favor of STEP systems should be reviewed
during the detailed design stage (Step II of the construction grant
process) on the basis of a detailed field survey of the existing on-site
systems. The arrangement of the STEP system house pump and sewer line
connection is illustrated in Figure III-l.
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^3
EXISTING GRAVITY
SEWAGE PIPING
EXISTING SEPTIC TANK
CONTROL PANEL
& ALARM LIGHT
PRESSURE SEWER/
COMMON
TRENCH
OVERFLOW
LEVEL SENSOR
ON OFF LEVEL
SENSOR
PUMP UNIT
STORAGE
TANK UNIT
FIGURE III-l
TYPICAL PUMP INSTALLATION FOR PRESSURE SEWER
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3. WASTEWATER TREATMENT
Wastewater treatment options are discussed here in three
categories: centralized treatment prior to discharge into surface
water; centralized treatment prior to disposal on land; and
decentralized treatment.
"Centralized treatment" refers to treatment in which wastewater is
collected and transported to a central location where it is treated and
discharged. Centralized treatment systems may serve all or a part of
the service area. Centrally treated effluent may be discharged to
surface waters or applied to the land; the method and site of disposal
affect the treatment process requirements.
"Decentralized treatment" defines those systems processing a
relatively small amount of wastewater. Decentralized treatment can be
provided on-site or off-site. Typically, effluent disposal occurs in
proximity to the source of sewage eliminating the need for costly
transmission of sewage to distant disposal sites.
A major purpose of this EIS is assessment of technical feasibility,
relative costs, environmental impacts, and implementation problems asso-
ciated with these three approaches to wastewater treatment in the pro-
posed Otter Tail Lake EIS Service Area.
a. Centralized Treatment
Alternatives developed in this EIS and in the Facility Plan
considered centralized treatment by both land application and mechanical
treatment. These alternative centralized treatment methods are
considered separately.
Mechanical Treatment with Stream Discharge. The Facility Plan
evaluated one option for centralized collection and treatment at a
mechanical plant; secondary treatment using activated sludge was
selected. The plant included provisions for phosphorus removal and was
to be designed to comply with MPCA effluent standards.
This EIS reevaluated the mechanical treatment plant option. The
proposed plant would be a modular prefabricated contact stabilization
plant, incorporating chemical addition for phosphorus removal. The
advantage of a modular system is that during off-peak season operation,
when flow will be reduced, half of tae biological train will be shut
down.
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In this manner the plant will be able to continue to operate at
maximum efficiency. The plant was designed to comply with MPCA current
effluent standards listed in Appendix C-6. The treated effluent would
be discharged to Otter Tail River, downstream of East Lost Lake, just
west of Deer Lake. This treatment scheme is illustrated in Figure
III-2.
b. Land Disposal
Land treatment of municipal wastewater involves the use of plants
and soil to remove many wastewater constituents. A wide variety of
processes can be used to achieve many different objectives of treatment,
water reuse, nutrient recycling, and crop production. The three
principal types of land application systems are:
1. Slow rate (irrigation)
2. Rapid infiltration (infiltration-percolation)
3. Overland flow (EPA 1977).
The effluent quality required for land application in terms of
organic content (BOD and suspended solids) is not as critical as with
stream discharge options. Pretreatment of wastewaters is necessary,
however, to prevent nuisance conditions, insure a higher level of
constituent removal through the soil, reduce soil clogging, and insure
reliable operation of the distribution system.
Storage of wastewater is necessary with land application systems
for non-operating periods and periods of reduced application rates
resulting from climatic constraints. In Minnesota land application
systems must have storage facilities for holding wastewaters over the
winter months.
A recent memorandum from EPA put forth the policy for pretreatment
prior to land application. To encourage both land treatment and land
disposal of wastewater, EPA has indicated that:
"A universal minimum cf secondary treatment for direct surface
discharge...will not be accepted because it is inconsistent
with the basic concepts of land treatment.
...the costs of the additional pre-application increment
needed to meet more stringent pre-application treatment
requirements [than necessary] imposed at the Scate or local
-evel would be ineligible for Agency funding and thus would be
paid for from State or local funds." (EPA 1978)
Other portions of EPA policy has important ramifications for land
treatment alternatives. By allowing Federal funding of land used for
storage and underwriting the risk of failure for certain lani-related
projects the policy promotes their consideration.
The Facility Plan developed two centralized land application
systems for the Proposed Service Area. One involved a spray irrigation
facility to the west of Otter Tail Lake to s^rve the entire Service
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FIGURE III-2
PREFABRICATED CONTACT STABILIZATION PLANT
ALUM 8 POLYMER
o
oo
PUMP
STA.
RAW
WATER
AERATED
GRIT
CHAMBER
FLOW
MEASURE-
MENT
ADDITION
SLUDGE DRYING
BEDS
OE
CHLORINATION
TO RECEIVING
STREAM
-------
Area. The other system involved a smaller spray irrigation facility at
this same site to serve a portion of the Service Area, along with
another spray irrigation facility south of Otter Tail Lake to serve the
remainder of the Service Area. In this EIS, both the spray irrigation
and rapid infiltration methods of land application were evaluated as
treatment options for the EIS Service Area. These are described below.
Spray Irrigation. For the various alternatives developed in this
EIS, a total of four different (design flow) spray irrigation facilities
were evaluated for serving all or part of the Service Area, at one or
both of the sites selected by the Facility Plan. Each of these
facilities consists of preliminary treatment (bar screen, comminutor), a
stabilization pond, and a chlorination process to disinfect the effluent
prior to its application on cropland. Because of the large
stabilization pond required to meet MPCA storage requirements, the
treatment plant component would provide secondary treatment prior to
spray irrigation as recommended by the MPCA (MPCA 1972). An application
rate of 2 inches per week was chosen based on the nitrogen loading rate.
No under-drainage would be needed at this rate. Higher loading rates
may produce poor crop growth. Alfalfa was chosen as the cover crop;
alfalfa allows a higher nitrogen loading and hydraulic loading than corn
and its growing season is limited solely by climatic factors. The
stabilization pond will serve the dual purpose of providing secondary
treatment and 210 days storage. A flow diagram of this plant is
illustrated in Figure III-3.
Figure III-3
SPRAY
IRRIGATION
RAW ^
WASTE
WATER
PRELIMI-
NARY
TREAT-
MENT
STABILIZATION POND 1
LAND APPLICATION
SPRAY IRRIGATION
Rapid Infiltration. The rapid infiltration method of land
treatment is evaluated for two sites in the new wastewater management
alternatives at design flows of 0.18 mgd and 0.12 .ngd. Rapid infiltra-
tion of wastewater was selected for further investigation as a component
option because it usually -requires less area for operation as compared
to spray irrigation, thus reducing capital costs.
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After land application the renovated wastewater will be drawn from
receiviag wells (see Figure III-4) and discharged into either Otter Tail
Lake, along the south shore or to the Otter Tail River below East Lost
Lake, depending upon the facility site location.
Figure III-4
RECOVERED
WATER
PERCOLATION
(UNSATURATEQ ZONE)
RECOVERY OF RENOVATED WATER BY HELLS
A flow diagram of this tyt>e of plant is illustrated in Figure
III-5.
RAW
WASTE
WATER
PRELIMI-
NARY
TREAT-
MENT
fe.
STABILIZATION POND
1
RAPID
NFILT
RATIOI
8ASINS
1
RECOVERY
WELLS
TO OTTER TAIL RIVER
DOWNSTREAM OF EAST
LOST LAKE OR TO OTTER
TAIL LAKE
LAND APPLICATION
RAPID INFILTRATION
FIGURE III-5
c. Decentralized Treatment and Disposal
A number of technologies are available which can provide decentral-
ized treatment either on-site or at sites near the point of sewage
generation. Disposal of treatment waslewaters can be to the air., soil
or surface waters and normally occurs near the treatment site. Some of
the available technologies are:
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Alternative toilets:
Composting toilets
Toilets using filtered and disinfected bath and laundry
wastewater
Waterless toilets "using oils to carry and store wastes
Incineration toilets
On-lot treatment and disposal:
Septic tank and soil absorption systems (ST/SAS)
Septic tank and dual, alternating soil disposal system
Aerobic treatment and soil disposal system
Septic tank or aerobic treatment and sand filter with
effluent discharge to surface waters
Septic tank and evapotranspiration system
Septic tank and mechanical evaporation system
Septic tank and sand mound system
Rejuvenation of soil disposal fields with hydrogen
peroxide (H202) treatments
Off-lot Treatment and Disposal:
Holding tanks
Cluster systems (multiple houses served by a common soil
disposal system)
Community septic tank or aerobic treatment and sand
filter with effluent discharge to surface water
Small scale lagoon with seasonal effluent discharge to
surface waters
Small scale lagoor. with affluent discharge at rapid
infil ration land application site
Small scale lagoon with seasonal effluent discharge at
slow rate land application site
Small scale, preconstructed activated sludge (package)
treatment plants with affluent discharge to surface
waters.
Ill
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Because all of the developed portions of the Study Area discharge
to lakes by runoff, decentralized technologies which discharge to
surface waters are not further considered here. All of the remaining
technologies, used alone or in combination with each other or with flow
reduction devices, could be useful in individual situations within the
Study Area. It is expected that, it the decentralized approach to
wastewater management is selected, technologies selected for each
dwelling will be appropriate to the problem being remedied (or lack of
problem), to the soil and groundwater site characteristics, and to the
expected use of the systems.
Information was not available to select appropriate decentralized
technologies on a site-by-site basis. Continued reliance on on-site
septic tank and soil absorption systems are recommended where public
health and the environment are not adversely impacted. Where on-site
systems are not economically, environmentally or otherwise feasible
alternative decentralized systems were considered. The assumptions used
in developing decentralized technologies were made to form the basis for
cost and feasibility estimates and are not meant to preclude other
technologies if detailed site investigation indicates a need for them.
Continued use of septic tank-soil absorption systems for most
dwellings in the Proposed EIS Service Area would perpetuate violations
of Minnesota's Shoreline Management Act as discussed in Section II.C.3.
More detailed site investigations may indicate the degree to which
renovation or replacement of some existing on-site systems is necessary.
To estimate the investment this might require, it is assumed that 50% of
on-site systems will be replaced with new septic tanks and conventional
soil absorption systems; 5% will be replaced with new septic tanks and
sand mound soil absorption system; 25% will require hydrogen peroxide
renovation treatment; and 2% will be required to install new holding
tanks.
Derailed site investigation may show that continued use of
conventional on-site septic tanks and soil absorptions systems may
result in groundwater contamination or shoreline eucrophication. One
method proposed to alleviate these problems is gray water/black water
separation. Household wastewater discharged into septic tanks usually
contains toilet wastes, the so called "black water" mixed with "grey
water" which includes discharges from sinks, tubs, clothes washing and
dish washing. Under the proposed separation scheme grey water would be
treated in ST/SAS and black water would be discharged to holding tanks.
Characteristics of effluents from grey water and blackwater differ
markedly, especially when non-phosphorus detergents are used. The per
capita nitrogen and phosphorus load from black wr.ter is approximately
12-13 times the corresponding load from gray water. Therefore by
eliminating black water from the subsurface disposal system, the
potential for groundwater contamination or leaching of nutrient to
surface waters is greatly reduced. Using this system, the hydraulic load
to the ST/SAS would be reduced by about 40%, and the nitrogen load by
about 90%and the phosphorus load by about 75% where a phosphorus ban is
in effect. In addition, the hydraulic load to the holding tanks would
also be significantly reduced by using low flush toilets (see Section
III.B.I). Pumping of holding tanks woald be required annually for
seasonal residents and two times a year fcr permanent residents.
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Costs for grey water/black water separation were based upon the
assumptions that 25% of the existing drainfields would need replacement
and that pumping for black water holding tanks would be required once a
year for seasonal residents and twice a year for permanent residents.
Design assumptions for grey water/black water separations are included
in Appendix 1-1.
Cluster systems were also investigated as a feasible alternative
where continued use of on-site systems is not feasible or where repairs
for a number of dwellings are more expensive than joint disposal.
Cluster systems are subsurface absorption systems similar in operation
and design to on-site soil absorption systems but are large enough to
accommodate flows from a number of (approximately 20) dwellings.
Because of the need to collect and transport wastes, cluster systems
include limited collection facilities using pressure sewers, small
diameter sewers and/or pumps and force mains. Generally, existing
septic tanks would continue to be used for settling and stabilization of
wastewater. As previously indicated, where shoreline housing density is
greater than 50 dwelling units per mile it may prove cost-effective to
use small diameter gravity sewers feeding one single pump at the low
point on the gravity line. Cluster collection systems of this kind are
also capable of serving more than the 25 homes used in the STEP system
design.
An analysis of soil conditions at selected sites around Otter Tail
Lake was conducted by the Soil Conservation Service, St. Peters,
Minnesota. The results of the SCS investigations are presented in
Figures II-3 to II-6. The size and distribution of suitable sites is
such that any portion of Otter Tail Lake shoreline could be served by
cluster systems if necessary. Before use of sites for this purpose,
additional analysis of soils and groundwater would be necessary.
The number and locations of dwellings requiring off-site disposal
of wastewater have been estimated in the new EIS decentralized alter-
natives. The exact numbers and locations however, would be determined
after a detailed house by house evaluation of existing systems.
The cost for cluster systems were developed based on the design of
a "typical" cluster system serving approximately 25 residences along the
shoreline of Otter Tail Lake. The costs include a 25% replacement of
septic tanks. The total cost for cluster systems to serve those areas
proposed in the various alternatives was then based on the cost per
residence from the typical cluster system design. Design assumptions
for this cluster system design appear in Appendix 1-1. Design criteria
for cluster systems recommended by the State of Minnesota were
considered in the development of the typical cluster system design.
Presently, there are a number of successfully operating cluster systems
in O^.ter Tail County, Minnesota (by letter, L-irry Krohn, Department of
Land and Resource Management, Otter Tail County, 18 October 1978.)
4. EFFLUENT DISPOSAL
Three approaches exist for disposal of treated wastewater. Reuse,
perhaps the most desirable of the three, implies recycling of the efflu-
ent by industry, agriculture cr groundwater recharge. Land application
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takes advantage of the absorptive and renovative capacities of soil to
improve effluent quality and reduce the quantity of wastewater requiring
disposal. Discharge to surface water generally implies the use of
streams or impoundments for ultimate disposal of treated effluent.
a. Reuse
Industry Reuse. There is no industrial development in the Study
Area, consequently industrial reuse is not a feasible means of effluent
disposal.
Agricultural Irrigation. The use of treated wastewaters for
irrigation is addressed in Section III.B.3.
Groundwater Recharge. Groundwater supplies all potable water in
the EIS Service Area. Ample quantities of water available from sand and
gravel deposits is a significant area resource. There is no evidence
that these resources are being depleted to an extent requiring recharge.
Wastewater reuse by groundwater recharge has therefore not been
evaluated.
b. Discharge to Surface Waters
This EIS evaluates surface water discharge of treated wastewater at
two locations in the Otter Tail Lake Study Area, as listed below:
Potential Location of Surface
Treatment Method Water Discharge
Contact stabilization
activated sludge
and Otter Tail River downstream
Rapid infiltration, with of East Lost Lake (Just west
renovated wastewater collected of Deer Like)
Rapid infiltration, with reno- Otter Tail Lake
vated wastewater collected
Effluent quality limitations promulgated by the MPCA and EPA will
govern the feasibility of implementing any of the wastewater treatment
components listed above. Concern over low dissolved oxygen due to
organic loading (BOD,, and Total Suspended Solids [TSS]) of streams has
prompted the MPCA to stipulate effluent limitations of 25 mg/1 BOD_ and
30 mg/1 TSS (sse Appendix C-6). Concern over the cultural
eutrophication* of lakes in Minnesota has prompted MPCA to stipulate
that total phosphorus levels in effluent be restricted to 1.0 mg/1. The
limitation applies to the Otter Tail River as well as to the lakes
within the Proposed Service Area. The State is currently reviewing
effluent limitation requirements and expects some revision of the
standards in approximately one year. The effluent quality limitation
regarding cotal phosphorus for discharge to lakes., however, will remain
at 1 mg/1 (by telephone, Lanny Piessig, MPCA, 20 October 1978).
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c. Land Application
Section III.B.3 briefly describes land application methods of
wastewater treatment that are evaluated for potential use in the Study
Area. Figure III-7 shows the locations of land application sites
considered in costing the EIS alternatives.
Please note that any actual construction of either rapid
infiltration or spray irrigation systems must follow a detailed field
investigation of the existing soil and groundwater conditions.
5. SLUDGE HANDLING AND DISPOSAL
Two types of sludge would be generated by the wastewater treatment
options considered above: chemical/biological sludges from secondary
and tertiary treatment processes; and solids pumped from septic tanks.
The residues from treatment by lagoons and land application are grit and
screenings.
This EIS has estimated the costs of these alternatives by assuming
that a contract hauler would be responsible for hauling and disposal of
sludge. A cost of $81 per million gallons of sewage was used, based
upon $30/1000 gallons of sludge and 2700 gallons of sludge per million
gallons of sewage. These costs have been incorporated into the
cost-effectiveness analysis presented in Chapter IV.
Alternatives using residential septic tanks for on-lot systems,
cluster systems, or STEP sewer systems, as well as holding tanks for all
domestic wastewater must provide for periodic removal and disposal of
the accumulated solids. For the purpose of design and costing these
alternatives, it is assumed that septic tank pumping would occur every 3
years and would cost $45 per pumping. Local septage haulers are
licensed to operate in Otter Tail County. Farm lands are typical
septage disposal sites. Pumping of holding tanks for human wastes only
(using air compression toilets to reduce flow) might be required
annually for seasonal residents and two times a year for permanent
resident and would cost $100 per pumping.
C. RELIABILITY
1. SEWERS
Gravity Sewers. When possible, sewer systems allow wastewater to
flow downhill by force of gravity. This system, the gravity sewer, is
highly reliable. Designed properly, such systems require little
maintenance. They consume no energy aad have no mechanical components
to malfunction.
Gravity sewer problems can include clogged pipes leading to sewer
backups; infiltration/inflow, increasing the volume of flow beyond the
design level; and broken or misaligned pipes. Major contributors to
these problems are improperly jointed pipes and the intrusion of tree
roots into the sewer. These problems are more prevalent in older
systems.
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Where ground slope is opposite to the desired sewage flow, it may
be necessary to pump the sewage through sections of pipe called force
mains. The pumps add a mechanical component increasing operation and
maintenance (O&M) requirements and decreasing the system reliability.
To assure uninterrupted operation of the system, two pumps are generally
installed, providing a backup in case of malfunctions. Each can usually
handle at least twice the peak flow. A standby generator usually
ensures operation of the pumps in case of a power failure.
Because the flow through force mains is intermittent, solids may be
deposited during periods of no flow. In addition, when the pumps shut
off, the sudden cessation of flow may cause the hydraulic conditions
known as "water hammer" in the force main, with sudden sharp surges in
water pressure that may result in burst pipes. However, both deposition
of solids and water hammer may be controlled through proper design
procedures. The reliability of properly designed force mains is
comparable to that of gravity sewers.
Pressure Sewers. Pressure sewers transmit wastewater uphill when
ground topography does not allow gravity flow. Because the system is
always under pressure, pumping is required to force the wastewater into
the sewer
Grinder Pumps. Grinder pumps are used primarily to grind and pump
raw domestic sewage from an individual house to the collection system
and occasionally for small lift stations. They are either of the
serai-positive displacement or the centrifugal type, depending upon the
mode of operation. The reliability of both types is high.
One problem may arise during a power failure. Standby power for a
grinder pump would not usually be available at an individual house and
the residence would be without sewage removal. This is a lesser problem
than might be supposed, for a power failure would curtail many
operations that generate wastewater.
There were problems in the operation of the first generation of
grinder pumps vhen pressure to pump wastewater or power to grind solids
was insufficient. Modifications have been made in their design and
construction, and the second generation of these pumps is appreciably
more reliable. Periodic maintenance is required to clean or replace
parts of the grinder pump.
Septic Tank Effluent Pumps* (STEP). I'; is sometimes desirable to
pump wastewater from an existing septic tank rather than directly from
the house, using STEP rather than a grinder pump. In this way
difficu?.ties associated with suspended solids are largely avoided. STEP
pumps are relatively simple modifications of conventional sump pumps.
The reliability of STEP made by experienced manufacturers is good.
Newer entries into the field have not yet accumulated the operating
experience necessary to demonstrate conclusively the reliability of
their products. In the event of f.'.ilure of a STEP system, an overflow
line may be provided, which permits passage of the septic tank effluent
to the old drainfield for emergency disposal.
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Pipes. Pressure sewer pipes are subject to the same problems as
force mains, discussed above. As with force mains, proper design can
prevent clogging and breaking of pipes, the most common cause of sewer
problems. Because pressure sewer piping has no mechanical components,
the reliability is high.
2. CENTRALIZED TREATMENT
Conventional. The reliability of conventional wastewater treatment
is time tested. Most unit processes have been used for many years, and
there is much information on their design and operation in nearly all
climates. In general, the larger the treatment facility, the more
reliable its operation, because the large volumes of flow require
multiple units per treatment process. For instance, a large facility
will have several primary clarifiers, and if one malfunctions, the
remaining units can handle the entire load. Therefore, difficulties
that arise as a result of failure of a single unit process, or of severe
weather conditions such as heavy rain or very cold temperatures, are
less likely to affect operations. Conventional wastewater treatment
plants can be designed to handle most problems.
Advanced Treatment. Advanced treatment serves primarily to remove
toxic substances and nutrients that would stimulate biological activity.
The technology is relatively new; experience in design and operation of
advanced treatment processes is therefore limited. However, when
designed properly, the reliability of these processes is high.
Land Application. Application of treated sewage effluent to the
land is a steadily growing treatment technology. Local climatic
conditions such as year round hea\n/ rains c_~ freezing temperatures aay
make the technique unsuitable in a particular area.
The feasibility of land application by spray irrigation has been
demonstrated for this geographic location at the Muskegon, Michigan site
which has operated effectively for 5 years. The feasibility of rapid
infiltration has been demonstrated at Lake George, New York, where rapid
infiltration of a small flow has been practiced over 40 years.
Potential problems with land application include: groundwater con-
tamination; dispersal of microbial mass by airborne transport; odors;
surface water contamination; accumulation of industrial c.etals in the
vegetation; and possible toxic effects upon local animals. These
problems can be minimized with proper design, but there is not yet the
extensive practical experience required tc develop advanced design
technology.
3. ON-SITE TREATMENT
Septic Tanks-Soil Absorption Systems. TUB design and operation of
modern septic tanks has benefited from long experience. Properly
designed and maintained, septic systems will provide satisfactory
service with minimum maintenance. Care must be taken not to put
materials in the system that may clog it. The principal maintenance
requirement is periodic pumping of the t.ink, usually every two or thi^e
years.
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Problems of septic tank systems include heavy rain saturating the
ground, clogged drainfields caused by full septic tanks, clogged or
frozen pipes, and broken pipes. Current environmental laws restricting
sites according to soil suitability, depth to groundwater and bedrock,
and other factors are limiting the cases where septic systems can be
used.
Sand Mounds. Elevated sand mounds above original ground level are
an alternative treatment system where siting restrictions do not allow
the use of standard drainfields. Because they do not always provide
satisfactory service under special conditions and are considerably more
expensive than conventional drainfields, they have not been universally
accepted.
4. CLUSTER SYSTEMS
Cluster systems are localized wastewater disposal mechanisms
servicing several (approximately 25) residences. The reliability is
similar to that of a septic tank system, except that a malfunction
affects not just one, but a number of residences. Because a cluster
system requires more piping to connect individual houses to the
treatment tank than does a series of individual systems, there is a
greater chance for pipes to break or clog, or for infiltration/inflow to
occur during heavy rain. If pumping is required, the reliability of the
system declines because of the mechanical nature of the pumps and their
dependence upon electrical power.
The experience with cluster systems in Otter Tail County, Minnesota
is described in Appendix 1-2.
D. FLEXIBILITY
Flexibility is a measure of the ability to accommodate growth or
changes in requirements that may be placed upon a system in the future.
This section examines the flexibility of the components within each
alternative and the operational restraints on each and design of the
facilities. These aspects of flexibility are discussed in terms of
their impacts upon choices of systems and decisions of planning and
design.
1. TRANSMISSION AND CONVEYANCE
For gravity and pressure sewer systems, flexibility is the ability
to handle future increases in flow. The ability to handle flows greater
than the original design flow is generally low, and an increase in
capacity is an expensive process. Also, the layout of the system
depends upon the location of the treatment facility. Relocation or
expansion of a finished facility would require costly redesign and
addition oi sewers.
Both gravity ac.d pressure sewers require minimum sewage velocities
to prevent deposition of solids which ^ould cause blockage. The
velocity of the fluid moving through gravity sewers depends mainly upon
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pipe slope. Contour of the ground surface is the principal determinant
of pipe slope and depth, and consequently, of construction costs.
Pressure sewers, however, can carry sewage uphill under pressure.
Because they do not depend upon slope to maintain the velocity of flow,
they offer the designer somewhat more flexibility than does gravity flow
pipe.
2. ON-SITE SEPTIC SYSTEMS
Septic systems are flexible, allowing custom design for each user.
As long as spatial and environmental parameters are met, the type of
system can be chosen according to individual requirements. This
flexibility is useful in some rural areas where centralized treatment
would be neither cost-effective nor desirable.
Existing septic systems can be expanded by adding more tank and
drainfield capacity, if suitable land is available. If it is, flow can
be distributed to an added system with little disturbance of the
existing system.
Cluster systems are septic systems that treat wastewatei from more
than one house, usually 15 to 24. The flexibility for design and
expansion of such a system is somewhat less than for a standard septic
system. Sizes of cluster systems range from one-quarter to one-half
acre, a substantial increase compared to a standard septic system
(typically about 1000 square feet). Right-of-way requirements for
piping must be considered because the system crosses a number of
property boundaries and may cross public property. The location of
other underground utilities such as water, electricity, gas, and
telephone must also be considered in the design.
An alternative system for on-site sewage treatment, such as an
elevated sand mound, is required where siting restrictions prohibit the
use of standard septic system and centralized collection of sewage is
not available. In these cases where some aspect of the environment is
unsuitable for on-site treatment of sewage, future expansion may be
difficult or impossible. Stipulations of health codes may restrict the
potential of the alternative systems for alteration or expansion.
3. CONVENTIONAL WASTEWATER TREATMENT
Ability to expand a conventional wastewater treatment plant depends
largely upon the process being used, layout of the facility, and
availability of additional land for expansion. Compared to many systems
for land application, conventional treatment processes require little
land, therefore increasing the flexibility for expansion. However,
unless the layout of the plant were dasigned for future additional
capacity, expansion could be hindered. Establishment of a facility such
as a sewage t-eatuent plant will redu-e flexibility for future planning
decisions within the affected mur.icipalities.
Because operators can, to some extent, vary treatment parameters,
most conventional processes have good operational flexibility. By
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altering the amounts and types of chemicals, flow rates, detention
times, or even process schemes, the required effluent can usually be
obtained.
4. CONTACT STABILIZATION
If the volumes of the contact and stabilization lagoons are
approximately equal in size, the system can be operated in parallel as
extended aeration, or as a contact stabilization process. By adding
more secondary clarifiers, the flexibility may be available to expand
the facility to conventional activated sludge without increasing reactor
volumes. This expansion depends largely upon configuration of the
basins and process operability. Contact stabilization is used generally
for small facilities, and does not have the flexibility to be expanded
to large flows.
5. LAND APPLICATION
To be flexible, a land application system should operate
efficiently under changing conditions, and should be easily modified or
expanded. These factors depend largely upon geographical location.
The ability to handle changes in treatment requirements and waste-
water characteristics is a specific measure of flexibility for a land
application facility. Furthermore, the level of treatment provided by
the land application system will in part determine whether it can handle
possible increases in flows in the future. Wastewater in Otter Tail
Lake Study Area consists primarily of domestic sewage and future changes
in composition of the wastewater are not likely to occur. If industrial
wastewater were added in the future, pretreatment at the industrial
source may be required.
Expandability is an important element of flexibility. Being able
to acquire additional land efficiently and economically as, future flows
increase depends upon the proximity of the facility to populated areas,
design and layout of the system, additional transmisison requirements,
and the type of application system used. A number of application
mechanisms are available spray, overland flow, or rapid infiltration.
Sites can be forest land, cropland, or open fields. Attention must be
paid, however, to characteristics of the surrounding laad, and to
possible future changes in land use. Also, requirements are strict
concerning tae hydraulic and geologic conditions of tho prcposad site.
When initially planning the facility, all of tie above mentioned con-
ditions shovild be taken into consideration if maximum flexibility for
future expansion is desired.
Cost of the land accounts for ^iuch of the capital cost for a land
application facility, and greatly affects the possibility of expansion
or ease of discontinuing the site. Because l»nd normally appreciates in
value, the final salvage val:a ^f the site may be very high after the
expected 20-year design life. If the site is abandoned, a large portion
of the initial capital cost of tiie facility may be recovered by
reselling the land at the appreciated price. I: should be noted,
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however, that the public may be reluctant because of its former use to
use the land; this would depend largely upon the appearance of the land
at the time of resale.
Finally, operational flexibility of land application systems is
highly dependent upon climate. When heavy rains saturate the soil or
flooding occurs, treatment efficiency is greatly reduced. Where cold
temperatures might make land application usable, storage facilities are
required. In very cold climates, up to six months of storage capacity
may be needed. Rapid infiltration is the only technique for land
application which has been used successfully in very cold temperatures.
E. IMPLEMENTATION
The process of implementing a wastewater management plan varies
with project reliance upon centralized or decentralized components.
Since most sanitary districts have in the past been designed around
centralized collection and treatment of wastewater, there is a great
deal of information about the implementation of such systems.
Decentralized collection and treatment is, however, relatively new and
there is less management experience on which to draw.
Regardless of whether the selected alternative is primarily
centralized or decentralized, four aspects of the implementation program
must be addressed:
There must be legal authority for a managing agency to exist
and financial authority for it to operate.
The agency must manage construction, ownership and operation
of the sanitary district.
A choice must be made between the several types of long-term
financing that are generally required in paying for capital
expenditures associated with the project.
A system of user charges to retire capital debts, to cover
expenditures for operation and maintenance, and to provide a
reserve for contingencies must be established.
In the following sections, these requirements are examined first
for centralized sanitary districts, then for decentralized districts.
1. CENTRALIZED DISTRICTS
a. Authority
The Otter Tail Lake Facility Plan recommended the formation of a
Sanitary Sewer District with members appointed by the County Commission
as the legal authority for implementing the Plan's Proposed Action.
Under Chapter :.76A of the Minnesota statutes, the District would have
the authority to implement this system and to contract with the villages
and townships for services.
121
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b. Managing Agency
The role of the managing agency has been well defined for
centralized sanitary districts. In general, the agency constructs,
maintains and operates the sewerage facilities. Although in fact
different contractual relationships exist between the agencies and their
service areas, for the purposes of this document ownership of the
facilities may be assumed to reside with the agency. For gravity
sewers, such ownership has traditionally extended to the private
property. For STEP or grinder pump stations connected to pressure
sewers several options exist:
The station may be designed to agency specifications, with the
responsibility for purchase, maintenance and ownership
residing with the homeowner.
The station may be specified and purchased by the agency, with
the homeowner repurchasing and maintaining it.
The station may be specified and owned by the agency, but
purchased by the homeowner.
The station may be specified, purchased and owned by the
agency. Regardless, however, of the option selected, all
residences are treated equally.
c. Financing
Capital expenses associated with a project may be financed by
several techniques. Briefly, they are:
pay-as-you-go methods;
special benefit assessments;
reserve funds; and
debt financing.
The Facility Plan suggested debt financing in the form of bonds but
did not specify the type of bonds (i.e., revenue, general obligation or
special obligation). Alternatively, the Facility Plan also suggested
that the proposed Sanitary District contact the Farmers' Home
Administration regarding a possible construction loan.
In Minnesota, counties, townships, and cities usually incur debt in
the form of general obligation bonds. The debt limit on such bonds is
set at 6-2/3% of the taxable valuation of the government unit. General
obligation bonds require voter approval in Minnesota.
d. User Charges
User charges are set at a level that will provide for repayment of
long-term debt and cover operating and maintenance expenses. In
addition, prudent management agencies frequently add an extra charge to
provide a contingency fund for extraordinary expenses and replacement of
equipment.
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Because of the potential economic impacts, the charges must be
carefully allocated among various classes of users. Recognized classes
of users include:
Permanent residents/Seasonal residents
Residential/Commercial/Industrial users
Presently sewered users/Newly sewered users
Low- and fixed-income residents/Active income producers
Each class of user imposes different requirements on the design and
cost of each alternative, receives different benefits, and has different
financial capabilities.
2. SMALL WASTE FLOW DISTRICTS
Regulation of on-lot sewage systems has evolved to the point where
most new facilities are designed, permitted and inspected by local
health departments or other agencies. After installation, local
government has no further responsibility for these systems until mal-
functions become evident. In such cases the local government may
inspect and issue permits for repair of the systems. The sole basis for
government regulation in this field has been its obligation to protect
public health.
Rarely have governmental obligations been interpreted more broadly
to include monitoring and control of other effects of on-lot system use
or misuse. The general absence of information concerning septic system
impacts on ground and surface water quality has been coupled with a lack
of knowledge of the operation of on-site systems.
Methods of identifying and dealing with the adverse effects of
on-lot systems without building expensive sewers are being developed.
Technical methods include both the wastewater treatment and disposal
alternatives discussed in Section III.B and improved monitoring of water
quality. Managerial methods have already been developed and are being
applied in various communities as discussed in Appendix J-l.
As with any centralized district, the issues of legal and fiscal
authority, agency management, project financing, and user charges must
all be resolved by small waste flow districts.
a. Authority
Minnesota presently has no legislation which explicitly authorizes
governmental entities to manage wastewater facilities other than those
connected to conventional collection systems. However, Minnesota
Statutes Sections 444.085, 444.065 and 444.075, and Chapter 116A have
been interpreted as providing cities, villages, counties, and special
purpose water and sewer districts, respectively, with sufficient powers
to manage decentralized facilities (Otis and Stewart 1976).
California and Illinois, to resolve interagency conflicts or to
authorize access to private properties for inspection and maintenance of
123
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wastewater facilities, have passed legislation specifically intended to
facilitate management of decentralized facilities. These laws are
summarized in Appendix J-2.
b. Management
The purpose of a small waste flow district is to balance the costs
of management with the needs of public health and environmental quality.
Management of such a district implies formation of a management agency
and formulation of policies for the agency. The concept of such an
agency is relatively new. Appendix J-3 discusses this concept in
detail.
The range of functions a management agency may provide for adequate
control and use of decentralized technologies is presented in Table
III-3. Because the level of funding for these functions could become an
economic burden, their costs and benefits should be considered in the
development of the management agency. Major decisions which have to be
made in the development of this agency relate to the following
questions:
Should engineering and operations functions be provided by the
agency or by private organizations under contract?
Would off-site facilities require acquisition of property and
right-of-way?
Would public or private ownership of on-site wastewater
facilities be more likely to provide cost savings and improved
control of facilities operation?
Are there environmental, land use, or economic characteristics
of the area that would be sensitive to operation and
construction of decentralized technologies? If so, would
special planning, education and permitting steps be
appropriate?
Five steps are recommended to implement an efficient, effective
program for the management of wastewater in unsewered areas:
Develop a site-specific environmental and engineering data
base;
Design the management organization;
Agency start-up;
Construction and rehabilitation of facilities; and
Operation of facilities.
Site Specific Environmental and Engineering Data Base. The data
base should include groundwater monitoring, a house-to-house investiga-
tion (sanitary survey), soils and engineering studies, and a survey of
124
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Table III-3
SMALL WASTE FLOW MANAGEMENT FUNCTIONS BY OPERATIONAL COMPONENT
AND BY BASIC AND SUPPLEMENTAL USAGE
Component
Basic Usage*
Supplemental Usage*
Administrative User charge system
Staffing
Enforcement
Engineering
Operations
Planning
Adopt design standards*
Review and approval of plans*
Evaluate Existing systems/
design rehabilitation
measures
Installation inspection*
On-site soils investigations*
Acceptance for public
management of privately
installed facilities
Routine inspection and
maintenance
Septage collection and
disposal
Groundwater monitoring
Grants administration
Service contracts supervision
Occupancy/operating permits
Interagency coordination
Property and right-of-way
acquisition
Performance bonding
requirements
Design and install facilities
for public ownership
Contractor training
Special designs for alternative
technologies
Pilot studies of alternative
technologies
Implementing flow reduction
techniques
Emergency inspection and
maintenance
Surface water monitoring
Land use planning
Public education
Designate areas sensitive
to soil-dependent systems
Establish environmental, land
use and economic criteria
for issuance or non-issuance
of permits
* Usage normally provided by local governments at present.
125
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available technologies likely to function adequately in the area. This
baseline information will provide the framework for the systems and
technologies appropriate to the district.
A program for monitoring groundwater should include sampling of
existing wells and possibly additional testing of the aquifer. Such
monitoring should be instituted early enough to provide data useful in
selecting and designing wastewater disposal systems. Concurrent with
the sampling of wells, the design and condition of wells should be
determined. Potential contamination sources should be identified.
The sanitary survey should include interviews with residents and
inspections of existing systems. A trained surveyor should record
information on lot size and location; age and use of dwelling; location,
age, and type of sewage disposal system; adequacy of the maintenance of
the existing system; water-using fixtures; and problems with the exist-
ing system. A preliminary sanitary survey of Otter Tail Lake shore
homes began in July 1979.
Detailed site analyses may be required to evaluate operation of the
effluent disposal fields and to determine the impacts of effluent dis-
posal upon local groundwater. These studies may include probing the
disposal area; boring soil samples; and the installation of shallow
groundwater observation shafts. Sampling of the water table downhill
from leach fields aids in evaluating the potential for transport of
nutrients and pathogens through the soil. Soil classifications near
selected leach fields may improve correlations between soils and leach
field failures. An examination of the reasons for the inadequate
functioning of existing wastewater systems may avoid such problems with
the rehabilitation or construction of new systems.
Design the Management Organization. Both the Facility Plan and the
EIS have recommended a Sanitary Sewer District as the agency best suited
to managing wastewater facilities in both unsewered and sewered areas of
the Study Area. The role of organizations such as the Department of
Health should be examined with respect to avoiding interagency conflicts
and duplication of effort and staffing.
Determination of the basic and supplementary management functions
to be provided will be influenced by the technologies appropriate to the
Study Area. In this respect, the questions raised earlier regarding
formulation of management policies must be resolved.
The product of these analyses should be an organizational design in
which staffing requirements, functions, interagency agreements, user
charge systems and procedural guidelines are defined.
Agency Start-Up. Once the structure and responsibilities of the
management agency have been defined, public review is advisable. Addi-
tional personnel required for construction and/or operation should be
provided. If necessary, contractual arrangements with private organiza-
tions should be developed. Acquisition of property should also be
initiated.
126
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Construction and Rehabilitation of Facilities. Site data collected
for the environmental and engineering data base should support selection
and design of appropriate technologies for individual residences. Once
construction and rehabilitation begin, site conditions may be revealed
that suggest technology or design changes. Since decentralized
technologies generally must be designed to operate within site
limitations instead of overcoming them, flexibility should be provided.
Personnel authorized to revise designs in the field would provide this
flexibility.
Operation of Facilities. The administrative planning, engineering,
and operations functions listed in Table III-3 are primarily applicable
to this phase. The role of the management agency would have been
determined in the organizational phase. Experience gained during agency
start-up and facilities construction may indicate that some lower or
higher level of effort will be necessary to insure long term reliability
of the decentralized facilities.
c. Financing
The financing of a small waste flows district is similar to that of
a centralized district. Such financing was discussed in Section
III.D.I.e.
d. User Charges
Although renovation and replacement costs for on-site systems owned
by permanent residents are eligible for Federal funding, such costs
incurred by seasonal, residents are not. The major difference in the
financing of the two systems arises from the question of seasonals'
ownership of on-site systems. With respect to the Study Area, where a
significant proportion of the users would be seasonal, the absence of
Federal funding would transfer a large fraction of the project costs to
the local users. This would be reflected in either 1) capital outlays
by the users for construction, 2) increased user charges covering
increased local costs or 3) both. The cost impact could however be
avoided by district ownership or easement access and control of on-site
treatment systems for dwellings occupied by seasonal residents. These
would then be eligible for Federal funding (EPA, Program Requirements
Memorandum 79-8; May 1979).
User charges and classes have been discussed in Section III.E.l.d.
The significance of decentralized districts lies in the creation of an
additional class of users. Since residents of such districts may be
differentiated in terms of centrally sewered areas and decentralized
areas, user charges may differ. As a result many different management
functions are conjoined. For example, permanent users on septic systems
may be charged less than those on central sewers. Seasonal users on
pressure sewers may have high annual costs associated with amortization
of capital expenses; permanent users of pressure sewers may be charged
less than seasonal users, because Federal funding reduced their share of
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the capital costs. Alternatively, the management agency may choose to
divide all costs equally among all users. For the analyses in this EIS,
public ownership of permanent and seasonal on-site systems has been
assumed.
Problems such as these have not been adequately addressed by the
historical sources of management information. Development of user
charges by small waste flows districts will undoubtedly be complicated
by the absence of such historical records. EPA is preparing an analysis
of equitable means for recovering costs from users in small waste flow
districts and combined sewer/small waste flow districts.
128
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CHAPTER IV
ALTERNATIVES
A. INTRODUCTION
1. APPROACH
The preceding section described options for the functional com-
ponents of wastewater management systems for the communities in the
Study Area. This section examines eight alternative courses of action
(including the Facility Plan Proposed Action and "No Action") for meet-
ing the wastewater management needs of the Proposed Service Area.
The Facility Plan Proposed Action provided for centralized collec-
tion and treatment of wastewater. In response to questions about need
for the expense of the Proposed Action, the development of EIS alter-
natives emphasizes decentralized and alternative or innovative
technologies: alternative collection systems, decentralized treatment
and land disposal of wastewaters. The EIS alternatives would manage
wastewaters in the same Service Area as the Facility Plan Proposed
Action, but five of the EIS alternatives use decentralized treatment to
varying degrees to minimize the costs of sewers.
Because of the high cost of collection in the Proposed Action, the
cost-effectiveness of pressure sewers, vacuum sewers, and small-diameter
gravity sewers was compared. Pressure sewers proved to be the most
cost-effective alternative method for collection of wastewater and were
used. A combination of pressure sewers and gravity sewer collector
systems proved cost-effective for all alternatives; this was also the
conclusion of the Facility Plan.
Where site conditions such as soils and topography are favorable,
land disposal of wastewater offers advantages over conventional biolo-
gical treatment systems that discharge to surface waters: the land is
used as a natural treatment facility system; reduced operation and
maintenance may result from relatively simple operations; and savings in
capital and operating costs are possible. The Facility Plan recommended
land treatment.
An analysis of site conditions indicated that decentralized treat-
ment technologies were a feasible alternative to sewering the entire
Otter Tail Lake shoreline for at least parts of the Proposed Service
Area. The Facility Plan had considered them, but did not have means to
sense the actual contributions of on-site systems.
2. ALTERNATIVES
The action proposed by the Facility Plan is compared with the
"do-nothing" (No Action) alternative, and 6 new alternatives developed
in this EIS, including a limited action alternative. The alternatives,
discussed below, are summarized in Table IV-I. Table IV-2 and a segment
129
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Table IV-1
ALTERNATIVES - SUMMARY OF MAJOR COMPONENTS
'ALTERNATIVE
Facility Plan
Proposed Action
Limited Action
Alternative
EIS
Alternative 1
EIS
Al t£fn3C i vc 2
CENTRALIZED
TREATMENT
Stabilization Ponds
(0.5 ogd)
Not Applicable
Stabilization Ponds
(0.12 mgd) serving
south shore of Otter
Tall Lake between
Lake Blanche and
Otter Tail Lake and
North shore of Lake
Blanche
Stabilization Ponds
south shore (0.12 mgd)
and west /northwest
TREATMENT PLANT
SITING
Northwest of
Lake In Atnor
(Section 32)
Otter Tail
Township
Not Applicable
South of Otter Tall Lake
In Ottei Tall
(Section 32)
Township
South of Otter Tall Lake
and northwest
Tail Lake in
of Otter
Amor Yownshlp
EFFLUENT
DISPOSAL
Land application by
spray irrigation with
recovery of renovated
wastewater and discharge
to Otter Tail River down-
stream of East Lost Lake
Not Applicable
Land application by:
A. Rapid Infiltration;
collection in recovery
wells; discharge to
Otter Tail Lake
or
B. Spray Irrigation
Land application by:
A Rapid infiltration*
collection in recovery
v-ells; two points of
ON LOT 4
CLUSTER SYSTEMS
No
On-lot systems serving all
residents. Grey water/black
with high groundwater Inflow.
On-site maintenance and up-
grade for the remaining shore-
line areas.
On-lot and cluster systems
serving remaining shoreline
areas
On-lot and cluster systems
and southeast shores
ALTERNATIVE
COLLECTION METHOD
Gravity sewers supplemented
by pressure sewers In low
lying areas
Not Applicable
Combination of gravity
sewers and pr< tire sewers
Combination of gravity
O
fl
r-l
Otter Tail River down-
stream of East Lost
Lake and the other to
Otter Tall Lake
EIS
Alternative 3
Alternative
-------
Table IV-2
DESIGN POPULATION AND FLOW (2000)
FOR SHORELINE AREAS
(I/I NOT INCLUDED)
Area
Southwest Shore
West /Northwest
Shore
Northwest Shore
East /Southeast
Segments
21-26
and
part of 20
1-4; 28-34
5-11 and
part of 12
13-19
and
part of 20
Total
Population
1,906
2,817
1,813
745
Winter
Population
396
594
457
188
Total Flow
(mgd)
0.12
0.18
0.11
0.043
Winter Flow
(mgd)
0.024
0.036
0.027
0.011
-------
map (see Figure IV-1) are included to facilitate the explanation of the
alternatives by showing the segments included in the northeast, south-
east, etc. sections of Otter Tail Lake. Table IV-3 ranks the alter-
natives for cost-effectiveness. Appendix K-l presents the assumptions
used in design and costing them.
a. No Action
As part of this EIS process, an evaluation must be made of the
consequences of not taking action. This No Action Alternative implies
that EPA would not provide funds to support new construction, upgrading,
or replacement of existing wastewater collection and treatment systems.
Presumably, then, no new facilities would be built and wastewater would
continue to be treated by existing on-site systems discussed in Section
II.C. The Otter Tail County Department of Land and Resources Management
would continue to regulate the use of on-site systems. Standards for
on-site systems, set forth in the Shoreland Management Ordinance, would
be enforced by this agency.
b. Facility Plan Proposed Action
The Facility Plan recommended treatment of all wastewater at a land
application site which would handle 0.56 mgd. Regional collection would
be accomplished through a system of gravity sewers supplemented with
pressure sewers utilizing grinder pumps in some low lying areas. Waste-
water would be conveyed to a site about one-third mile west of Otter
Tail Lake in Amor Township (Section 32). The wastewater would be
treated by stabilization ponds and chlorination and subsequently applied
to the land by spray irrigation. A center pivot distribution system was
incorporated into the design and costing of the alternative.
To maintain comparability of alternatives for purposes of cost
analysis, the Facility Plan Proposed Action was slightly modified for
consideration in this EIS. The following changes were included:
The design flow of 65 gpcd used in the Facility Plan was
reduced to 60 gpcd, not including infiltration and inflow;
The population projections for the year 2000 presented in this
EIS are slightly more (0.9%) than the Facility Plan projec-
tions and total flows were adjusted to accomodate the change
in population;
The net effect of these changes is a reduction in the total
flow by 12% from 0.56 mgd to 0.50 mgd; and
Grinder pumps were replaced with septic tank effluent pumps
(STEP) because of a slight cost advantage of the STEP system.
The Facility Plan Proposed Action was also costed with the incorporation
of flow reduction devices. The estimated flow is 0.38 mgd. The Facil-
ity Plan Proposed Action is briefly described in Chapter 1 and was
outlined in detail in Chapter 3 of the Facility Plan (Ulteig Engineers
1976). Figure IV-2 is a map of che Proposed Action. Appendix K-2 lists
major components of the alternative and the cost of these components.
132
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OTTER TAIL LAKE
SEGMENT LOCATION
MAP
OTTER TAIL RIVER
to
-------
TABLE IV-3
COST EFFECTIVE ANALYSIS OF ALTERNATIVES
LIMITED EIS 1 EIS 1 EIS 2 EIS 2
ACTION SPRAY RAPID SPRAY RAPID FACILITY PLAN
ALTERNATIVE IRRIGATION INFILTRATION IRRIGATION INFILTRATION ElS 3 EIS 4 EIS 5 PROPOSED ACTION
Present Project
Construction
Costs (x $1,000) 3,253.A 7.144.6 7,141.6 0,411.3 8,446.6 9,027.2 9.931.1 9.689.4 10,146.5
Future Project
Construction
Costs (x $l,000/yr) 228.3 129.9 129.9 107.9 107.9 85.8 82.7 39.0 39.0
Total Present
Worth (x $1,000) 7,152.2 9,306.8 9,296.4 10,202.8 10,168.9 10,539.6 11,336.0 10,245.7 10,358.6
Average Annual
Equivalent Costs
($) 655.9 852.5 851.6 934.6 931.5 965.4 1,038.4 938.5 948.8
-------
N
LEGEND
= FORCE MAIN
= GRAVITY SEWER
: PUMP STATION
NOTE: ALL GRAVITY LINE ARE
8"DIA. UNLESS NOTED.
NOT TO SCALE
SPRAY IRRIGATION: NO
STREAM DISCHARGE
LAND
APPLICATION
-ROUND LAKE
OTTER TAIL
VILLAGE
FIGURE IV-2 FACILITY PLAN PROPOSED ACTION
-------
c. Limited Action Alternative
This alternative would include decentralized systems for all parts
of the Proposed Service Area. Gray water/black water separation would
be used in those segments where groundwater contamination or shoreline
eutrophication could result from subsurface treatment of black water.
Gray water, generated from sinks, tubs, showers, and dishwashing
and clothes washing would be treated in a conventional septic tank/soil
absorption system. Black water or toilet wastes would be discharged to
holding tanks. Air compression, low flush toilets would be used to
reduce the hydraulic load to the holding tanks and the frequency of
pumping. Pumping of holding tanks would be required annually for
seasonal residents and twice a year for permanent residents. Composting
toilets may be installed as an alternative to the use of low flush
toilets and holding tanks. This option would considerably reduce the
user charges discussed in Section V.E.
Residences not served by gray water/black water separation would
use a single ST/SAS for both black waLer and gray water. This alter-
native would include a program of replacement and rehabilitation of
on-lot systems, where necessary, to alleviate existing water quality and
public health problems. This program would be generally similar to that
proposed in EIS Alternative 1.
Figure 1V-3 shows the Limited Action Alternative. Design and cost
assumptions are detailed in Appendix K-2. Please note that future
capital costs for new dwellings would be borne by the owner at time of
construction, just as they are today.
d. EIS Alternative I
EIS Alternative 1 would use decentralized treatment of wastewater
for most of the Proposed Service Area. Centralized collection would be
provided for a small area on the south shore of Otter Tail Lake, between
Lake Blanche and Otter Tail Lake. This area is characterized by high
groundwater conditions and was considered unsuitable for on-site treat-
ment. A flow of 0.12 mgd collected from this area would be conveyed by
a combination pressure and gravity collection system to a suitable site
approximately 2,000 feet from the shore of Otter Tail Lake in Otter Tail
Township. The wastewater would be treated in stabilization ponds and
applied to the land using either rapid infiltration or spray irrigation.
Effluent which would be disposed of by spray irrigation would be chlori-
nated prior to application for disinfection. With rapid infiltration
effluent would be collected in recovery wells and pumped to Otter Tail
Lake.
The remaining parts of the Service Area would be served by a com-
bination of cluster systems and on-site systems depending upon local
conditions. The distribution of these decentralized systems rests upon
the following assumptions:
136
-------
N
H
U>
-J
LEGEND
GRAY WATER/BLACK WATER
SEPARATION
] ON-SITE MAINTENENCE AND
UPGRADE
OTTER TAIL RIVER
OTTER TAIL
VILLAGE
OTTER TAIL TWP_
GIRARO TWP
-ROUND LAKE
FIGURE IV-3 LIMITED ACTION ALTERNATIVE
-------
N
LEGEND
Y//A -- ON SITE, ST-SAS
= CLUSTER SYSTEMS
- PRESSURE SEWER
= GRAVITY SEWER
- PUMP STATION
NOTE: ALL GRAVITY LINE ARE
8"DIA. UNLESS NOTED.
OTTER TAIL RIVER
NOT TO SCALE
OJTER TAIL
VILLAGE
oo
n
I. SHAY WJHiATJON; NO tTflf AM
WtCMAMi
l« RAPID INFILTRATION: Ol
or MCftow
TO OTTER TAIL LAKE
OTTER TAIL TWP
GIRARD TWP
ROUND LAKE
FIGURE IV-4 EIS ALTERNATIVE 1
-------
Cluster Systems. Cluster systems would be used for those parts of
the Proposed Service Area which are unsuitable for on-site treatment for
one or more of the following reasons:
small lot sizes;
shallow depth to groundwater level; or
location within an area having a high hydraulic head such that
groundwater (and septic leachate) flow rapidly towards Otter
Tail Lake.
It is estimated that approximately 670 residences would be provided
with cluster systems in 1980 and about 950 residences by the year 2000.
It was assumed that about 25% of the septic tanks for cluster systems
would need replacement.
On-Lot Systems. Residences not served by sewers or cluster systems
would use on-lot systems. This alternative would include a program of
replacement and rehabilitation of on-lot systems where necessary to
alleviate existing malfunctions.
The assumption that 50% of the on-site systems need replacement was
based upon an estimate by the Department of Land and Resources Manage-
ment (L. Krohn, Land and Resources Management Office, May 1978).
However, a detailed investigation of on-site systems has not been made
at this time. Site evaluations and selection of appropriate replacement
or rehabilitation technologies are likely to result in variation from
this assumption in both the number of systems affected and the mix of
technologies. The following assumptions were made regarding upgrading
and replacement of on-site systems.
80% of the on-site systems need some type of work and 2/3 of
these systems need replacement (L. Krohn, Land and Resources
Management Office).
Therefore, 50% of the on-site systems will be replaced with
conventional septic tank-soil absorption systems.
» 5% of the on-site systems will be replaced with mound systems.
2% will be provided with holding tanks because of unsuitable
site conditions.
25% of the existing systems will be given hydrogen peroxide
treatment.
EIS Alternative 1 is shown irt Figure IV-4 and design costs and assump-
tions are derailed in Appendix K-2.
e. EIS Alternative 2
EIS Alternative 2 resembles EIS Alternative 1 providing de-
centralized treatment for much of the Proposed Service Area, but
139
-------
LEGEND
ON SITE, ST-SAS
CLUSTER SYSTEMS
PRESSURE SEWER
FORCE MAIN
GRAVITY SEWER
PUMP STATION
NOTE: ALL GRAVITY LINE ARE
8"DIA. UNLESS NOTED.
OTTER TAIL RIVER
OTTER TAIL
r^\ VILLAGE
NOT TO SCALE
1. smwr'ftttfATION; NO STRUM !
2o
OK R«NQV«TW WAiTS
TO OTTti TAIL LAKI
LAND APPLICATION
./ LAKE
7 BLANCHE
4. SPRAY iftWe*Tte«l MO 8THCA*
D49CMAMK
t«. MP(OH*flkTIUTK>N:OtSCH
9t RC*0₯ATI0
DOWNSTREAM OP CAST LONt
LAKE
ROUND LAKE
FIGURE IV- 5 EIS ALTERNATIVE 2
-------
centralized collected and treatment for the south shore. However, the
number of on-site treatment systems has been reduced by sewering a small
area along the west/northwest shore of Otter Tail Lake. A wastewater
flow of 0.18 mgd from this area would be conveyed by a combination of
gravity and pressure sewers to a site on 2000 feet west of Otter Tail
Lake in Amor Township (site proposed in the Facility Plan). The waste-
water from both small flow areas would be treated in stabilization ponds
followed by either spray irrigation (after disinfection) or rapid infil-
tration. If wastewater is treated by rapid infiltration, 0.12 mgd of
renovated wastewater would be recovered and pumped to Otter Tail Lake
and 0.18 mgd would be recovered and discharged to the Otter Tail River
downstream of East Lost Lake.
The remainder of the Area would be served by on-site treatment
systems and cluster systems. The distribution of these decentralized
systems would be based upon site limitations for ST/SAS and the density
of developable lots. EIS Alternative 2 is illustrated in Figure IV-5.
Appendix K-2 lists design and cost assumptions used in developing this
alternative.
f. EIS Alternative 3
As with EIS Alternative 2, wastewater would be collected for treat-
ment at two separate land application sites. However, the collection
system proposed for the west/northwest shore would be extended to
include the entire north shore of Otter Tail Lake and the south shore of
Walker Lake and Long Lake. This alternative is illustrated in Figure
IV-6. The land application sites would be in the same place, but the
site located west of Otter Tail Lake expanded to handle a design flow of
0.3 mgd. EIS Alternative 3 uses only spray irrigation as the method of
land application.
The east shore and part of the southeast shore of Otter Tail Lake
would be served by on-site treatment systems or cluster systems. Homes
along the east/southeast shore are generally on larger lots well above
the groundwater table and consequently would need few cluster systems.
Appendix K-l presents design and costing assumptions used in developing
this alternative. Appendix K-2 lists major components of the alter-
native and their costs.
q. EIS Alternative 4
EIS Alternative 4 would centralize collection and treatment of
wastewater for the entire Service Area using two separate land appli-
cation treatment systems. Figure IV-7 shows how the Otter Tail shore-
line from Pelican Bay South to an area just beyond the north shore of
Lake Blanche would be collected and conveyed to one land application
site. The remaining segments would be collected and treated at the land
application site west of Otter Tail Lake. Both flows would be
treated in stabilization ponds, chlorinated and applied to the land by
spray irrigation. The same land application sites proposed for EIS
Alternatives 2 and 3 would be used.
141
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N
LEGEND
= ON SITE, ST-SAS
- CLUSTER SYSTEMS
5 PRESSURE SEWER
= FORCE MAIN
= GRAVITY SEWER
: PUMP STATION
NOTE: ALL GRAVITY LINE ARE
8"OIA. UNLESS NOTED.
OTTER TAIL RIVER
NOT TO SCALE
SPRAY IRRIGATION; NO
$THEAM
LAND
APPLICATION
OTTER TAIL
f^A VILLAGE
eg
FIGURE IV- 6 EIS ALTERNATIVE 3
-------
LEGEND
ON SITE, ST-SAS
CLUSTER SYSTEMS
PRESSURE SEWER
FORCE MAIN
GRAVITY SEWER
PUMP STATION
NOTE: ALL GRAVITY LINE ARE
8"DIA. UNLESS NOTED.
OTTER TAIL RIVER
LONG \% it
LAKE
SPRAY IRftl6ATlON;MO
LAND
APPLICATION
MNMV iftftHMTMW: H«
WHAM Ot*CMMItt
OTTER TAIL TWP
AMOR TWP
EVERTS TWP
OTTER TAIL
RIVER
OTTER TAIL
VILLAGE
V /
ROUND LAKE
FIGURE IV-7 EIS ALTERNATIVE A
-------
Appendix K-l lists design and costing assumptions used in develop-
ing this Alternative. Appendix K-2 lists major components of the
alternatives and their costs.
h. EIS Alternative 5
EIS Alternative 5 would centralize collection and treatment of
wastewater at a prefabricated contact stabilization plant. The package
plant, in Amor Township west of Otter Tail Lake, would be a modular
system capable of handling 0.5 mgd. The plant would incorporate
chemical addition for phosphorus removal and would discharge to the
Otter Tail River, downstream of East Lost Lake. Figure IV-8 shows the
proposed plant location. Appendix K-2 list the facilities included in
the design of the plant.
3. FLEXIBILITY OF ALTERNATIVES
a. No Action
The No Action Alternative maintains the existing conditions placing
no additional planning or design restrictions upon wastewater treatment.
Because no action is taken at present, the flexibility for future
planning is high compared to an alternative recommending an extensive
commitment of resources.
b. Facility Plan Proposed Action
A centralizing land treatment for all wastewater flows within the
Proposed Service Area reduces the flexibility for future planning and
design changes concerning wastewater treatment. This alternative
commits the entire Proposed Service Area to one treatment scheme
involving an extensive commitment of resources. However, expansion of a
land application facility is relatively simple as long as sufficient
environmentally suitable land is available adjacent to the existing
site.
c. Limited Action Alternative
Under the Limited Action Alternative, existing systems would be
repaired and upgraded. Residences located in areas with high groundwater
flow rates would be served by gray water/black water separation systems.
The main benefit of this alternative is that it would meet environmental
requirements while leaving maximum flexibility for future planning and
design changes.
d. EIS Alternative 1
Compared to the more centralized alternatives, the limited sewering
proposed in this alternative would result in greater flexibility for
future planning and design changes withir. the unsewered sections of the
Study Area. Also, the decentralized nature of tne alternative would
allow the flexibility to base future decisions concerning land use
development upon local conditions.
144
-------
N
LEGEND
= FORCE MAIN
= GRAVITY SEWER
= PUMP STATION
OTTER TAIL RIVER
NOT TO SCALE
NOTE: ALL GRAVITY LINE ARE
8"OIA. UNLESS NOTED.
r'
£-
Ln
PACKAGE
PLANT
NOTE: DISCHARGE OF PLANT EFFLUENT *i« l0'
~1 TO OTTEH TAIL RIVER DOWNSTREAM ,0"
| OF EAST LOST LAKE
i
t
ROUND LAKE
FIGURE IV- 8 EIS ALTERNATIVE 5
OTTER TAIL
VIL.LAGE
-------
e. EIS Alternatives 2, 3 and 4
EIS Alternatives 2, 3 and 4 differ only in the amount of Proposed
Service Area sewering. EIS Alternative 2 would have the least sewering
and consequently the greatest flexibility for future changes, while EIS
Alternative 4 would have the most sewer and the least flexibility. For
EIS Alternatives 2 and 3, not sewering the entire Proposed Service Area
would have a smaller immediate commitment of resources than the Proposed
Action in the Facility Plan. This would allow some ability for future
expansion and changes in localized planning. On the other hand, EIS
Alternative 4 would sewer the entire Proposed Service Area, offering
more opportunities for development of additional building sites.
f. EIS Alternative 5
Like the Facility Plan Proposed Action, this alternative would
commit the entire Proposed Service Area to one treatment approach. The
resulting commitment of resources and reduction in future planning and
design flexibility would be signficant. Although EIS Alternative 4 also
calls for sewering the entire Service Area, EIS Alternative 4 would have
two separate treatment sites, with slightly greater flexibility for
future changes than EIS Alternative 5.
146
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CHAPTER V
IMPACT EVALUATION
A. IMPACTS ON SURFACE WATER QUALITY
1. PRIMARY IMPACTS
a. Analysis of Eutrophication Potential
This section discusses the effects of the phosphorus loadings
associated with the different wastewater management alternatives. The
discussion centers on phosphorus because it is usually the controlling
nutrient in temperate lakes and is more easily controlled than nitrogen.
The major sources of phosphorus were identified in Chapter II as:
Tributaries and non-point sources;
Precipitation;
Immediate drainage; and
Septic tanks systems.
Future Phosphorus Loading Scenario. The relative contributions of
the major phosphorus sources to Otter Tail Lake and the small surround-
ing lakes were shown in Table II-6 for the existing conditions. In
this analysis, future phosphorus loading levels are projected to the
year 2000 for each alternative. These loadings are shown in Table V-I.
To show the change in phosphorus loads for each alternative, compared to
existing conditions, a percent change has been calculated. The results
of this analysis indicate that total phosphorus loads to Otter Tail
Lake, Deer Lake, Walker Lake, Long Lake and Lake Blanche would be mini-
mally effected by any alternative. This is because the load from septic
tanks is very small compared to that from precipitation and tributaries.
ST/SAS downslope of Lake Blanche, Long Lake and Walker Lake leach
towards Otter Tail Lake, rather than towards these smaller lakes, there-
by minimizing the loads. Although the ST/SAS do leach into the surface
waters of Otter Tail Lake, the total phosphorus loads from septic tanks
is still small compared to other sources; the drainage area of 1,140 mi2
for Otter Tail Lake represents a very significant source of uncontroll-
able nutrient input which reaches Otter Tail Lake as runoff through
tributaries.
Another factor contributing to the small change in nutrient loads
for the various alternatives is that none of the alternatives are anti-
cipated tc induce significant growth which would increase the non-point
source load.
In contrast, the phosphorus load to Round Lake could be increased
by as much as 100% over the planning period. Septic tanks contribute a
large percentage of the phosphorus load because non-point sources are
limited by the small watershed areas and by the land locked nature of
the lake.
147
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Table V-l
PHOSPHORUS LOADS BY ALTERNATIVE (KR/YR) AND PERCENT CHANCE COMPARED TO EXISTING CONDITIONS
ALTERNATIVE
Existing
Conditions
A
No Action
B
A
Limited Action
B
1 - Rapid
Infiltration
1 - Spray
Irrigation
2 - Rapid
Infiltration
2 - Spray
Irrigation
3
4, 5, Proposed
Action
OTTER TAIL LAKE
KG/YR
7,580
7,525
7,606
7,423
7,606
7,567
7,536
7,434
7,403
7,381
7.329
7,351
(Alt. 4)
CHANGE
-
Increase
Increase
-------
EIS Alternatives 2, 3, 4, 5 and Facility Plan Proposed Action
recommend centralized treatment for Round Lake. These alternatives
would significantly decrease phosphorus loads. The Limited Action
alternative would eliminate the major nutrient source from septic tanks
by eliminating black water* discharge.
As the surface water quality discussion in Chapter II indicated,
the nutrient load estimates were based on limited but best available
data. More complete sampling and land use data may modify phosphorus
load estimates, particularly for tributaries.
Future Trophic Conditions. Future trophic conditions will largely
be determined by the in-lake phosphorus concentration which is a func-
tion of the phosphorus load as well as of certain physical characteris-
tics of the lake basin. It is doubtful that the trophic status of Otter
Tail Lake, Lake Blanche, Walker Lake, Long Lake and Deer Lake will
change over the planning period since phosphorus loads will remain
fairly constant. The empiric Dillon model was used to determine the
trophic status of Otter Tail Lake for each wastewater alternative. The
model results, shown in Figure V-I indicate that Otter Tail Lake will
remain mesotrophic throughout the planning period no matter which waste-
water management alternative is implemented.
The Dillon model was also used to predict the trophic status of
Round Lake. Despite a large increase in phosphorus loads to Round Lake
with the No Action Alternative or EIS Alternative 1, the lake is antici-
pated to remain oligotrophic. The physical characteristics of Round
Lake allow the lake to assimilate much larger phosphorus loads without a
significant change in trophic status.
The conditions of Otter Tail River would probably not be changed by
the implementation of any of the wastewater management alternatives. If
effluent guidelines are met satisfactorily, some phosphorus and nitrogen
load would be added to the River, but this amount would be small in
relation to the load already being carried.
Shoreline Conditions. It is not expected that the shoreline condi-
tions(i.e.,algaegrowth) of Walker Lake, Long Lake or Lake Blanche
will be significantly effected by any of the wastewater management
alternatives. Since groundwater flow is towards Otter Tail Lake is is
unlikely that significant septic leachate would reach these smaller
lakes. However, the shoreline conditions of Otter Tail Lake, Round Lake
and Bser Lake may be impacted by the continued reliance on on-site
systems. A high correlation has been found between the location of
septic leachate plumes and shoreline algae growth in other oligotrophic
and mesotrophic lakes. Although algae growth is not a serious problem
along the shoreline of Deer Lake, Round Lake and Otter Tail Lake at the
present time, this condition will not necessarily remain constant
throughout the planning period as housing density and use of ST/SAS
increase.
The centralized alternatives would eliminate septic tanks as a
potential source for shoreline eutrophication. The Limited Action
Alternative would eliminate the major nutrient source by eliminating
149
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EUTROPHIC
OTTEK TAIL LAKE
8 NO ACTION
ALTERNATIVE 1.2,S; LIMITED ACTION
ALTERNATIVE 4,8; PROPOSED ACTION
ROUND LAKE
O NO ACTION
OLIGOTROPHIC
O ALTERNATIVE I
O LIMITED ACTION
I I I I I 1 I I
0.01
.006
.ALTERNATIVE 2,3,4,5;
PftOPOtEO ACTION
10.0
MEAN DEPTH (METERS)
100.0
LS AREAL PHOSPHORUS INPUT (g/m^yr)
R=PHOSPHORUS RETENTION COEFFICIENT
P= HYDRAULIC FLUSHING RATE (yr"1)
FIGURE v-i TROPHIC STATUS OF OTTER TAIL AND ROUND LAKES
UNDER VARIOUS ALTERNATIVES
150
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black water discharge which contains about 90% of the total nitrate load
from domestic wastewaters and a majority of the phosphorus load where a
detergent phosphorus ban exists.
b. Bacterial Contamination
Data indicate insignificant bacterial contamination of the lakes
within the Proposed Service Area under existing conditions (see Appendix
C-4). The probability that bacteriological contamination would occur
from EIS Alternatives 1 through 4, involving rapid infiltration and
discharge of recovered wastewater effluent to Otter Tail Lake or spray
irrigation is expected to be low. Land application of wastewater is an
effective way of eliminating or immobilizing sewage-borne pathogens
particularly if some pretreatment (stabilization pond) precedes the
application (Johnson et al.). Similarly, continued reliance on on-site
systems should not lead to bacterial contaminations, provided these
systems are maintained. Kerfoot found very low bacterial levels even
when samples were collected at the site of a leaching septic tank.
Bacterial pathogens undergo rapid dieback in the soil matrix. Studies
have shown the summer survival rate of fecal coliforms organisms to be
0.001% after a period of 35 days (Miller 1973). Although studies of the
groundwater flow rate have shown that septic tank leachate may reach the
surface water in a shorter time period, no evidence of widespread
bacterial contamination has been observed. The potential for bacterial
contamination of Otter Tail Lake in the Service Area should be more
specifically addressed following field sampling of the proposed waste-
water effluent.
c. Non-Point Source Loads
Primary impacts on surface water quality related to the construc-
tion of ST/SAS and the replacement of old systems are likely to result
in temporarily increased soil erosion. Similarly, installation of
sewers, especially those passing under the many small drainageways
leading to the lakes, would increase erosion.
Compliance with State and local soil erosion control requirements
could substantially reduce the erosion problem and the subsequent impact
on water quality.
2. SECONDARY IMPACTS
Growth in the Proposed Service Area is anticipated to concentrate
in the near-shore areas, in a single tier development pattern.
Some increased housing development is anticipated regardless of
which wastewater management alternative is selected. The centralized
alternatives may result in slightly higher shoreline development densi-
ties. Increased housing development along lake shores may increase
nutrient and sediment loads into the lake. This process may be further
accelerated with the centralized alternatives. L'iicre-.sed loads may
result from:
151
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Increased runoff from construction of impervious surfaces such
as rooftops and parking areas;
Lawn and garden fertilization creating unnaturally high
nutrient levels in the runoff; and
Soil disruption by human activities (i.e., housing construc-
tion, leveling of forested area, etc.).
Soil organic debris and dissolved materials mobilized and transported to
temporary runoff channels during storms are settled, filtered and ab-
sorbed on the land or in pools if the runoff channels are long or if
adequate storage areas, like wetlands, are present. Increasing housing
density normally accelerates storm runoff, thereby increasing not only
the amount of runoff but also its ability to erode soil and to transport
contaminants.
Although an increase in non-point source runoff is anticipated with
increased development, this increase would be small in comparison to the
total non-point source load increased development would occur in the
immediate watershed which represents only a small percentage of the
total 1,140 square mile watershed area. The major nutrient source to
Otter Tail Lake would continue to be the Otter Tail River.
3. MITIGATIVE MEASURES
The Shoreland Management Ordinance of Otter Tail County, Minnesota
(1 May 1973) protects shoreland alterations. The Ordinance suggests
several different methods to control runoff and erosion during grading
and filling operations. These measures will go far toward preventing
non-point sources of pollution from entering surface water bodies.
However, erosion and sediment control measures are concerned only with
construction processes, and limited to shoreland. As impervious surface
cover is developed, hydrologic head in runoff will increase, creating
flows capable of eroding and carrying considerably more sediment. In
order to address these closely related problems an overall runoff con-
trol program should be implemented.
As part of the Shoreland Management Ordinance, consideration should
be given to the feasibility of enacting a package of environmental
performance standards that would control stormwater, erosion, and sedi-
mentation. This approach would require that the amount of runoff from
any specific development does not exceed the carrying of the natural
drainage system. This would require runoff from development not to
exceed that which occurs under natural conditions.
The results of Kerfoot's study (April 1979) have shown that the
density and intensity of septic leachate plumes are influenced largely
by the direction of grouiidwater flow. Mitigative measures to reduce
septic leachate discharges include use of flow reduction devices, and
use of cluster systems which are set back from the shoreline.
152
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B. IMPACTS ON GROUNDWATER
Groundwater impacts fall into two categories: those affecting the
available quantity of the resource, and those affecting its quality.
1. GROUNDWATER QUANTITY IMPACTS
No significant primary or secondary impacts on groundwater quantity
are anticipated with any of the various alternatives; the wastewater
flows associated with the alternatives are relatively small, in compari-
son to the estimated groundwater supply and yield.
The conversion from sewage disposal practices based on individual
soil absorption systems to central collection and treatment systems
without land application of effluent can result in a loss of groundwater
recharge. The significance of this loss depends upon its relationship
to the recharge from all other sources, including downward infiltration
and percolation, and inflow from adjacent aquifers. The maximum possi-
ble wastewater recharge to the Study Area's aquifers in the design year
2000 is estimated to average 0.46 mgd for the No Action Alternative.
This is insignificant in relation to the estimated average recharge of
100 mgd to the aquifers by precipitation and to the 160 billion gallons
stored within the aquifer. Failure to return, to the aquifer ST/SAS
wastewater flows is therefore not expected to have a significant impact
upon groundwater quantity and availability within the Study Area.
2. GROUNDWATER QUALITY IMPACTS
Primary Impacts. Sedimentation and erosion may increase during
construction associated with the various alternatives. These impacts
are anticipated to be short lived and minor.
Secondary Impacts. Long term impacts on pollutants are mainly
associated with the following three types of pollutants: 1) bacteria,
organics and suspended solids, 2) phosphorus and 3) nitrogen in the form
of nitrates.
Bacteria and suspended organics are readily removed by downward
movement through approximately 5 feet of soil. These contaminants are
very unlikely to present problems in those parts of the Study Area where
the aquifer is overlain by loamy soils and depth to the water table
exceeds 5 feet. In areas where the water table is nearer to the surface
and soils are very sandy with high infiltration rates well water con-
tamination can occur with continued reliance on on-site systems.
However, available results from well water sampling show that bacterial
contamination is currently very localized. The use of grey water/black
water separation proposed in the Limited Action Alternative would
eliminate a major source of potential bacterial contamination by
eliminating subsurface treatment of blackwater. The use of cluster
systems (EIS Alternative 1 and 2) would reduce the potential for
bacterial contamination of well water by locating the absorption fields
away from high groundwater areas.
153
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The impact of phosphorus in groundwater is considered important
because of the potential for this nutrient to leach into surface waters
and cause algal growth.
Jones et al. (1977), in a comprehensive review of relevant studies
on this subject for the EPA concluded that:
...it is very unlikely that under most circumstances, sufficient
available phosphate would be transported from septic tank waste-
water disposal systems to significantly contribute to the excessive
aquatic plant growth problems in water courses recharged by these
waters.
This review has indicated that there are two primary factors in the
removal of phosphates applied to the land. The first is the tendency of
phosphorus to adsorb on small amounts of clay minerals, iron oxide, and
aluminum oxide in soil and aquifer materials. This reaction may not be
significant in some of the sandy soils along the lake shore. The second
is that hard waters precipitate phosphate, making it unavailable for
plant uptake. This second reaction is probably more significant in the
soils surrounding Otter Tail Lake.
Jones et al. (1977) have indicated several studies in areas similar
to the Study Area in which loamy soils overlie glacial outwash deposits
where the soil has essentially removed all phosphorus in septic tank
effluents. They also stated that in areas with hard water the "likeli-
hood of significant phosphate transport from septic tank wastewater
disposal system effluent to the surface waters is greatly reduced
because of the calcium carbonate present in the soil and subsoil
systems."
Despite Jones' finding, Kerfoot (1979) observed a high frequency of
phosphorus breakthrough in areas of high groundwater flow. He found
that most on-site systems along the shoreline of Otter Tail Lake were
leaching phosphorus into the surface waters. Complete quantification of
phosphorus loads were not available from this survey and the lake will
be resurveyed during the summer of 1979 for this purpose.
There is no evidence that under the existing conditions nutrient
levels are sustained in concentrations sufficient to cause excessive
shoreline algae growth or lake eutrophication.
Phosphorus leachate to surface water would be substantially reduced
by implementing the Limited Action Alternative since black water is a
major source of phosphorus from domestic wastewater. This reduction
would be greatest if a local phosphorus ban were enacted. The central-
ized alternatives would eliminate septic leachate as a source of phos-
phorus to Otter Tail Lake, Deer Lake and Round Lake.
High concentrations of nitrates in grounowauers are of concern
because methemoglobinertda* occurs in infants who consume foods prepared
with such waters. A limit of 10 mg/1 of nitrates expressed as nitrogen
(N03-N), has been set in the National Interim Drinking Water Regulations
(40 CFR 141) of the Sale Drinking Water Ace P.L. 93-523.
154
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Under the favorable moisture, temperature and oxygen conditions
that exist in the well drained soils, the nitrogen compounds of human
wastes are rapidly oxidized at or near land surface to soluble nitrates
which are not removed by passage through soils down to groundwaters. On
entry into groundwaters, nitrates are transported in the direction of
flow with consequent reduction in concentration as a result of dilution.
Where septic tank-soil absorption units are used, their density has
been stated as the most important parameter influencing pollution levels
of nitrates in groundwater. However, the same source has further indi-
cated that currently available "information has not been sufficiently
definitive nor quantitative to provide a basis for density criteria "
(Scalf et al. 1977).
The Shoreland Management Ordinance (1973) requires location of
septic tank systems at least 50 feet from any private water supply, such
as a well or spring. This distance usually provides enough travel time
for water within the aquifer to dilute and reduce initially excessive
nitrate concentrations (more than 10 mg/1 as NOs-N) to less than 2 mg/1.
Field studies in Minnesota by Schroepfer and Polta (1969) have shown a
reduction from 12.6 mg/1 to 1.7 mg/1 within 30 feet of travel at depths
of less than 15 feet in a water table aquifer. Most sanitary codes
reflect the general acceptance of a 50 foot separation of wells and
septic tank systems. A minimum lot size of 1/3 acre is usually adequate
to ensure the observance of the 50 foot separation of wells and
ST/SAS's (EPA 1977). However, some existing lots within the Proposed
Service Area are undersized and preliminary results of the sanitary
survey show that some septic tanks cannot meet the minimum setback
requirements from wells. Many of these same systems are poorly main-
tained and the potential exists for groundwater contamination under
existing conditions or with the No Action Alternative.
The partial use of grey water/black water separation, proposed in
the Limited Action Alternative would eliminate about 90% of the nitrogen
from domestic wastewater. This would greatly reduce the potential for
nitrate contamination of well water in areas using these systems.
The use of cluster systems is proposed for certain shoreline areas
to overcome the problem, but it would be subject to the findings of
detailed studies to be undertaken during the design phase of the proj-
ect.
Cluster system soil absorption fields are designed like septic tank
fields to ensure an adequate areal distribution of the effluent and
depth to groundwater for satisfactory treatment. Nitrate levels enter-
ing groundwater should be equivalent to those of leachate from ST/SAS's.
Locating the soil absorption fields of cluster systems at greater
distances from residential developments (500 feet adopted for EIS de-
sign) provides more thai; ample room for dilution of nitrate concentra-
tions below drinking water limits prior to interception by wells.
Cluster system alternatives should therefore produce no significant
groundwater nitrate impacts.
155
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Land application by spray irrigation can provide "sufficient nitro-
gen removals to produce a soil percolate below 10 mg/1 of NOa-N" (EPA
1977). If nitrogen input does not greatly exceed crop requirements for
nitrogen, crop uptake can effect 35 to 60% removals. Removals by
denitrification ranges from 15 to 70% depending upon the soil properties
and the application rate. Appropriate management of nitrogen loading
rates to minimize crop uptake and adjustment of application rates to
minimize denitrification, could possible to maintain groundwater quality
that meets drinking water standards for nitrates. Land application on
suitable loamy soils at a slow rate of 2.0 inches per week as proposed
in EIS Alternatives 1, 2, 3, and 4 should result in no adverse ground-
water impacts.
Land application by rapid infiltration achieves approximately 50%
nitrogen removal under field conditions (EPA 1977). This removal
efficiency is obtained by denitrification with low application rates and
appropriate flooding and drying cycles. The proposed application rate
of 12 inches per week should allow maximum denitrification. Well
recovery of the applied wastewater before it enters the aquifer would
further ensure compliance with the drinking water standard of 10 mg/1 of
NO,.-N. Alternatives using this effluent disposal method should there-
fore cause no significant adverse impacts on groundwater.
C. IMPACTS ON POPULATION AND LAND USE
Area capacity to support development varies with the degree to
which wastewater treatment facilities are site-related. On-lot systems
are extremely site-related and usable only where the soil is suitable.
Sewers allow development to be much more independent of site character-
istics because the soil, permeability, slope and drainage are not such
strong constraining factors. With centralized treatment, the major
development constraint is treatment system capacity. By providing
sewers, the developable land acreage can be increased as well as the
density to which it can be developed. The amount of additional growth
that will actually take place if sewers are provided depends not only
upon the development potential but also upon the demand for additional
residential development in the area. This demand reflects the attrac-
tiveness of the land for development compared to other areas and the
reduction in the cost of residential land when the supply of developable
land is increased.
This section evaluates, and Table V-2 summarizes, the probable
impacts of the various alternatives on population and land use. For
this purpose, the alternatives have been grouped into four categories,
depending upon the extent of sewering.
Decentralizec Treatment: Limited Action Alternative.
Completely Centralized Collection and Treatment System: Facility
Plan Proposed Action and EIS Alternatives 4 and 5.
156
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Table V-2
COMPARISON OF POPULATION AND LAND USE IMPACTS
ASSOCIATED WITH MAJOR SYSTEM ALTERNATIVES
Completely Centralized
Management Facilities
(EIS Alternatives 4, 5
and Facility Plan
Proposed Action)
Management Facilities
with an Intermediate
Extent of Centralization
(EIS Alternatives 2 & 3)
Least Centralized
Management Facility
(EIS Alternative 1)
Limited Action
Alternative
3g
S3-
U oJ
-------
Combination of Centralized, Cluster and On-site Systems; EIS Al-
ternatives 2 and 3.
Limited Centralized Collection and Treatment: EIS Alternative 1.
1. IMPACTS ON POPULATION
Population impacts are evaluated by comparing the baseline popu-
lation projections for the year 2000 (see Section II.E.I) with the
estimated population capacity supported by each wastewater management
alternative.
It was estimated that the total population of the Proposed Service
Area would increase by 19% by the year 2000 (baseline projections). All
but the Limited Action Alternative provide some sewering and allow some
increased growth above the baseline projections. Sewering eliminates
some natural constraints thereby allowing for additional growth. How-
ever, most land in the Proposed Service Area is already considered
developable and increases are not expected to be significant.
The No Action Alternative and the Limited Action Alternative would
result in population growth approximately equal to the baseline popula-
tion projections. Induced growth above baseline levels would increase
with degree of centralization. If the least centralized system (EIS
Alternative 1) were provided, total population in the Service Area would
be anticipated to increase 3% above the baseline projections by the year
2000. EIS Alternatives 2 and 3 would result in a population increase
about 6% above baseline projections. The most centralized alternatives,
the Facility Plan Proposed Action and EIS Alternatives A and 5, could
induce population growth up to 9% above the baseline projections.
Centralized treatment and collection is not expected to induce
significant population growth outside the Service Area. Second tier
(backlot) development is unlikely during the planning period because
more desirable lakeshore areas are available in the Proposed Service
Area and throughout the region. New development activity along current-
ly undeveloped portions of Deer, Round, Blanche, Walker, and Long Lakes
is also unlikely because more desirable building sites for seasonal
dwellings are available on the larger lakes in the region.
However, total demand in the region for seasonal residences will
ultimately determine the development pressure in the Proposed Service
Area for additional dwelling units beyond the baseline projections.
Currently, the demand for seasonal units appear to have stabilized and
is anticipated to decline slightly during the planning period.
2. LAND USE
a. Development Potential
To accommodate the population projected for the year 2000, approxi-
mately 400 to 500 acres of land would be developed. Only small incre-
mental increases in residential acreage are anticipated regardless of
the wastewater management alternative adopted. EIS Alternative 1 would
158
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result in development of an additional 15 to 20 acres above the 400 to
500 acres required for the baseline population. EIS Alternatives 2 and
3 would increase development by 25 to 30 acres, and the completely
centralized alternatives are anticipated to increase development by 50
acres.
The construction of new permanent dwelling units is expected to be low
because the rural Service Area is distant from employment centers and
urban amenities. Most of the additional permanent units projected for
the year 2000 are expected to result from the conversion of seasonal
units. The sizeable increase in seasonal units projected for the
Service Area baseline population (276 units) should satisfy the demand
for this type of unit.
b. Residential Land Use Patterns
The configuration of the wastewater treatment facilities often de-
termines the pattern of future land use; however, this is probably not
the case for the Proposed Service Area. It is expected that development
will occur in the same general areas (i.e., lakeshore lots) regardless
of which wastewater management alternative is adopted. Only minor
variations in land use patterns are expected to occur. The Facility
Plan Proposed Action and EIS Alternatives 4 and 5 would promote the
filling in of residential areas along the entire lakeshore of Otter Tail
Lake and the developing segments of Blanche, Round, Deer, Walker, and
Long Lakes which are in the Proposed Service Area. The change would
occur, but to a lesser extent, with EIS Alternatives 1, 2 and 3, depend-
ing upon the extent of sewering.
Residential densities throughout the Service Area are anticipated
to remain relatively low (1 to 2 dwellings per acre) and uniform. The
densities in the Service Area will be determined largely by the lot size
requirements specified in the Shoreland Management Ordinance.
c. Industrial, Service and Resort Land Use Impacts
The baseline population projections assume that the number of
non-residential facilities (commercial and service establishments) would
remain constant during the planning period. The population growth
projected, although substantial, is not likely to warrant the develop-
ment of additional commercial and service establishments in the Service
Area due to the high percentage of seasonal population. New commercial
and service establishments required to serve this increased population
would probably develop in the more urbanized areas such as Fergus Falls
where a larger year-round population exists to support the business.
The potential development of nursing homes, campgrounds, and trail-
er parks cannot be predicted at this time. Discussions with local
residents and officials of the Study Area indicated that no new develop-
ment of these kinds is currently planned. A telephone survey of resort
owners in the Service Area did, however, reveal a planned increase of
approximately 100 units during the planning period, mostly through
expansion of existing resorts. The potential provision of wastewater
management facilities apparently had no bearing on the expansion plans.
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3. CHANGES IN COMMUNITY COMPOSITION AND CHARACTER
The composition and character of the Otter Tail Lake area would be
moderately influenced by the provision of centralized wastewater facil-
ities. Additional costs of wastewater treatment would displace some
lower income permanent residents.
It is not likely that the conversion from seasonal to permanent
residences would be significantly stimulated by any wastewater manage-
ment alternative which is adopted, since the Study Area is not near
major employment centers or the amenities of urban areas. The baseline
projections assumed that retirement age homeowners might convert their
residences from seasonal to permanent use at a rate of 0.5% per year.
Centralized treatment facilities may increase this rate only slightly.
Land values should not be significantly influenced by the provision
of centralized and/or clustered wastewater management facilities. Most
vacant land in the Proposed Service Area is already developable under
existing conditions and desirable lakefront lots are available. As the
Service Area approaches a built-out condition near the end of the plan-
ning period, land values may increase with the demand for seasonal
units. However, the EIS Alternatives will impact land values only to
the extent that they neutralize areas with natural constraints.
D. ENCROACHMENT ON ENVIRONMENTALLY SENSITIVE AREAS
1. WETLANDS
a. Primary Impacts
Construction of a centralized collection systems might increase
sedimentation loads to some wetland areas and modify the water cir-
culation patterns in these areas during construction. Those wetland
areas include:
Wetland Alternative
Between Otter Tail River and Lake
Blanche (Segment 27) Facility Plan Proposed Action
Banks of the Otter Tail River near
the discharge from Otter Tail Lake 2, 3, 4, 5, Proposed Action
Between Otter Tail Lake and Lake Blanche 1, 2, 3, 4, 5, Proposed Action
Low lying areas west of Amor Park-North
Shore 2, 3, 4, 5, Proposed Action
Along the shoreline of Walker Lake 3, 4, 5, Proposed Action
Impacts during construction may be minimized by adhering to the
requirements of the Shcreland Management Ordinance regarding Shoreland
alterations.
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b. Secondary Impacts
Minnesota statutes require a permit for the alteration of cattail
wetlands (type III or IV wetland) of over 10 acres. The wetlands along
the southern shore of Otter Tail Lake between Otter Tail Lake and Lake
Blanche are shrub wetlands and would not have protected status from the
State. Another adjacent area of shrub wetlands, between the western
shore of Lake Blanche and the Otter Tail River outlet is protected by a
Federal easement which prevents it from being drained or filled. The
remaining wetland areas are composed primarily of cattail wetlands.
Considering the protection afforded under the Minnesota statutes
and the limited induced development anticipated under any of the waste-
water management alternatives evaluated, it appears that direct impacts
on wetlands would be very limited. Development pressures along the
southern shore of Otter Tail Lake would impact the wetlands in that
area, but these development pressures would exist under the No Action
Alternative as well as the other wastewater management alternatives
evaluated.
c. Mitigative Measures
Construction-related impacts can be minimized by restoring the
wetland areas to their original configuration as soon as possible.
Sediment traps such as diversions or terraces should be used where
possible to keep sediment from reaching wetland areas. The Land
Resources Administration should strictly enforce the Shoreland Man-
agement Ordinance with respect to shoreland alterations.
2. FLOODPLAINS
a. Primary Impacts
Construction of a centralized collection system would temporarily
impact flood-prone areas along the Otter Tail River and Pelican Bay.
Construction would result in some additional sediment loading which
would increase until new vegetation stabilizes the eroding sediments.
These impacts would be short-lived.
b. Secondary Impacts
The Shoreland Management Ordinance requires that any structure in
the 100-year floodplain be built 3 feet above the high water mark.
However, most houses were constructed before the Ordinance was adopted,
and relatively little remaining land in the Proposed Service Area is
undevelopable as a result of this restriction. The provision for off-
site wastewater management facilities would not significantly alter the
amount of developable land in the Proposed Service Area.
Areas of induced development along the shoreline areas of Lake
Blanche, Long Lake, Walker Lake, and Round Lake generally lie outside
flood-prone areas and would have little impact on the floodplain.
161
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c. Mitigative Measures
The provisions of the Shoreland Management Ordinance regarding con-
struction in the floodplain should be strictly enforced. Where resi-
dences already exist in flood-prone areas, drinking wells should be
floodproofed according to procedures established in statewide standards
and criteria for Management of Flood Plain Areas of Minnesota.
3. STEEP SLOPES
a. Primary Impacts
Steep slopes are rare along the developable areas of the Otter Tail
lakeshore and increased erosion and sedimentation resulting from con-
struction on steep slopes will be minimal. The only steep-sloped areas
that may be impacted by construction are located east of Amor Park on
the north shore and a small area along the southeast shore.
b. Secondary Impacts
There is at present only limited residential development in the
steep-sloped areas east of Amor Park on the north shore and along a
small area of the southeast shore. However, there are no local or state
regulations governing development in steep sloped areas, and residential
development in such areas along Otter Tail Lake is likely to continue
whether improved wastewater management facilities are provided or not.
The localized impacts from development in steep slope areas would in-
clude accelerated soil erosion and the resultant increases in turbidity
and non-point nutrient loads (primarily phosphorus).
c. Mitigative Measures
Municipalities should adopt performance standards with specific
slope/ density provisions and should limit growth in steep sloped areas
by zoning. Developers would then have to meet the performance standards
which bear proof that the sloped areas are not a hazard to development.
If cluster systems or septic tanks are placed in areas with steep
slopes, a series of drop boxes should be used. With this method no
hillside seepage should occur unless the sewage flow exceeds the design
capacity.
4. PRIME AGRICULTURAL LAND
No designation of prime agricultural lands has been made in Otter
Tail County as detailed soil mapping is not yet complete. The only
portions of the Study Area that are likely candidates for designation as
prime farmlands are located northwest and west of Otter Tail Lake.
These areas lie outside the Proposed Service Area and are not likely to
be affected by the construction of wastewater management facilities or
by development dependent on thsse facilities.
ic2
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5. FORESTS AND WOODLANDS
a. Primary Impacts
Coastruction of centralized collection systems would disrupt some
forested land but these impacts are not anticipated to be significant.
b. Secondary Impacts
Limited amounts of forest and woodland acreage would be converted
to developed land during the planning period. Generally, these areas
are located along Pelican Bay, the southeastern portion of Long Lake,
the northern portion of Round Lake, and the southern shore of Otter Tail
Lake. Most of this forested land would be converted to developed
acreage whether improved wastewater management facilities were provided
or not. However, the more centralized wastewater management alterna-
tives are likely to convert 15 to 25 more acres of forested land to
residential use.
6. ARCHAEOLOGICAL AND HISTORICAL SITES
Although the Minnesota Historical Society is conducting a compre-
hensive statewide survey of archaeological and historical sites, Otter
County has not yet been surveyed. It is known that artifacts and burial
sites are located in the Proposed Service Area, but their location is
confidential. Detailed site investigations will be performed by an
archaeologist after design specifications for the selected alternative
have been completed. The Morrison Mounds Historical Site and the Saint
Paul House are located within the Proposed Service Area; design specifi-
cations will be appropriately reviewed to resolve potential conflicts
between preservation of these sites and the selected EIS Alternative.
E. ECONOMIC IMPACTS
1. INTRODUCTION
The economic impacts of the proposed wastewater system alternatives
proposed for the Otter Tail Lake area are evaluated in this section.
These impacts include: financial burden on system users; financial
pressure causing residents to move away from the Study Area (displace-
ment pressure); and financial pressure to convert seasonal residences to
full-year residences (conversion pressure).
2. USER CHARGES
User charges are the costs periodically billed to customers of the
wastewater system. User charges consist of three parts: debt service
(repayment of principal and interest), operation and maintenance costs,
and a reserve fund allocation assumed to equal 20% of the debt service
amount. The reserve fund consists of depositing and investing a portion
of current revenues to accumulate adequate funds to finance future
needed capital improvements. Estimated user charges for each alterna-
tive are presented in Table V-3.
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Table V-3
ANNUAL USER CHARGES
ALTERNATIVE AVERAGE ANNUAL USER CHARGE
Facility Plan Proposed Action $350
Limited Action Alternative $165
EIS Alternative 1 $180
Spray Irrigation
EIS Alternative 1A $175
Rapid Infiltration
EIS Alternative 2 $210
Spray Irrigation
EIS Alternative 2A $210
Rapid Infiltration
EIS Alternative 3 $240
Spray Irrigation
EIS Alternative 4 $260
EIS Alternative 5 $375
a. Eligibility
Eligibility refers to that portion of wastewater facilities costs
determined by EPA to be eligible for a Federal wastewater facilities
construction grant. Capital costs of wastewater facilities are funded
under Section 201 of the 1972 Federal Water Pollution Control Act Amend-
ments and the Clean Water Act of 1977. The 1972 and 1977 Acts enable
EPA to fund 75% of total eligible capital costs of conventional systems
and 857o of the eligible capital costs of innovative and alternative
systems. Innovative and alternative systems considered in the EIS
include land treatment, pressure sewers, cluster systems, and septic
tank rehabilitation and replacement. The state of Minnesota funds 15%
of the capital costs of conventional treatment systems and 6% of the
capital cost of innovative/alternative systems. At the present time the
State does not fund collection systems whether they are conventional or
innovative/alternative. Operation and maintenance costs are not funded
by the Federal government and must be paid by the users of the facili-
ties.
The percentage of capital costs eligible for Federal and State
funding greatly affects the cost that local users must bear. Treatment
capital costs were assumed to be fully eligible for grant funding while
collection system capital costs were considered ineligible. The final
determination of grant eligibility will be prepared by the Minnesota
Pollution Control Agency.
321 E15 16A
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b. Calculation of User Charges
The user charges developed for the Otter Tail Lake alternative
systems consist of local capital costs, operation and maintenance costs,
and a reserve fund charge. The calculation of debt service was based on
Local costs being paid through the use of a 30-year bond at a 6-7/8%
interest. The user charges in Table V-3 are presented on an annual
charge per household basis.
Estimated annual user charges for the nine alternatives differ
significantly depending upon the extent of sewering. The user charges
range from $165 for the Limited Action Alternative to $375 for EIS
Alternative 5.
In addition to user charges, households connected to a gravity
sewer would have to pay the capital costs (approximately $970) of the
sewer connection. Pressure sewer connections are eligible for Federal
funding and do not represent a private cost to homeowners. Seasonal
homeowners also may have to pay the full price for the replacement or
rehabilitation of their on-site systems (septic tanks and soil absorp-
tion systems) if these systems are not made accessible to the local
wastewater management agency. Similarly residents would have to pay the
cost of purchase and installation of microphor toilets for the Limited
Action Alternative. These private costs would vary from household to
household due to differences in the distance to the gravity collector
sewer and the condition of on-site systems. Overall, the Limited Action
Alternative and EIS Alternative 1 would eliminate most or all of at
least $1,500,000 in provate costs. The user charges for the Limited
Action Alternative would be further reduced if composting toilet were
used instead of microphor toilet and holding tanks.
3. LOCAL COST BURDEN
a. Significant Financial Burden
High-cost wastewater facilities may place an excessive financial
burden on users of the system. Such burdens may cause families to alter
their spending patterns substantially. The Federal government has
developed criteria to identify high-cost wastewater projects (The White
House Rural Development Initiatives 1978). A project is identified as
high-cost when the annual user charges are:
1.5% of median household incomes less than $6,000;
2.0% of median household incomes between $6,000 and $10,000;
and
2.5% of median household incomes greater than $10,000.
The 1978 median household income for the Proposed Service Area has
been estimated to be $12,000 for permanent residents. (No dats. are
available for seasonal resident incc.-ne characteristics.) According to
the Federal criteria, annual user charges should not exceed 2.5% ($200)
165
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of the $12,000 median household income figure. Any alternative having
annual user charges exceeding $300 is identified as a high-cost alter-
native and is likely to place a financial burden on users of the system.
Both the Facility Plan Proposed Action and EIS Alternative 5 are classi-
fied as high-cost according to the Federal criteria.
Significant financial burden is determined by comparing annual user
charges with the distribution of household incomes. Families not facing
a significant financial burden would be the only families able to afford
the annual wastewater user charges. Table V-4 shows the percentage of
households estimated to face a significant financial burden under each
of the alternatives. The centralized alternatives would place a
financial burden on 60 to 70% of households in the Otter Tail Lake area,
while the Limited Action Alternative would financially impact about 35%
of the households. Only 30 to 40% of the area's households would be
able to afford the centralized systems while 62 to 70% of the residents
could afford the Limited Action Alternative and EIS Alternative 1.
b. Displacement Pressure
Displacement pressure is the stress placed upon families to move
away from the service area as a result of costly user charges. Dis-
placement pressure is measured by determining the percentage of house-
holds having annual user charges exceeding 5% of their annual income.
Table V-4 lists the displacement pressure induced by each alternative.
The centralized alternatives would be expected to place displacement
pressure on 30 to 40% of the households in the Otter Tail Lake area.
The Limited Action Alternative would displace only 8 to 12% of the
households and EIS Alternative 1 would displace 10 to 15%.
c. Conversion Pressure
Wastewater facilities costs are likely to encourage the trend
already underway of converting seasonal residences to permanent resi-
dences. The requirements would impose a relatively heavier cost burden
on seasonal residences than on permanent ones. These residences would
typically be used only three or four months during the year but would be
charged for capital costs throughout the year. This may place a
financial burden on seasonal residents who are maintaining a full-time
residence elsewhere in addition to their seasonal residence. The higher
cost burden of centralized alternatives will exert more conversion
pressure than the cost burden of the decentralized alternatives.
Because of the apparent high income of seasonal residents (based on
visual inspection of seasonal residences) the number of seasonal-to-
permanent residential conversions as a result of the wastewater user
charges is likely to be small in any case.
4. MITIGATIVE MEASURES
The significant financial burden and displacement pressure on users
in the unsewered areas may be mitigated by selection of a lower cost
decentralized alternative. The local wastewater management authority
may seek to obtain a loan or grant from the farmers Home Administration.
Such a loan would decrease annual user charges by spreading out the
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Table V-4
FINANCIAL BURDEN AND DISPLACEMENT PRESSURE
(BASED ON 0% ELIGIBILITY)
Alternative
Displacement
Pressure
Financial
Burden
Can
Afford
Facility Plan
Proposed Action
Limited Action
30-40%
8-12%
60-70%
33-38%
30-40%
62-67%
EIS Alternative #1
Spray Irrigation
10-15%
35-40%
65-70%
EIS Alternative #1A
Rapid Infiltration
10-15%
35-40%
65-70%
EIS Alternative #2
Spray Irrigation
10-15%
40-50%
50-60%
EIS Alternative #2A
Rapid Infiltration
10-15%
40-50%
50-60%
EIS Alternative #3
Spray Irrigation
EIS Alternative #4
EIS Alternative #5
20-30%
20-30%
30-40%
50-60%
50-60%
60-70%
40-50%
40-50%
30-40%
167
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payment of the local share over a longer period of time with a lower
interest rate. The impacts of the high costs to seasonal users may be
mitigated by not charging for operation and maintenance during the
months that seasonal residences are vacant. Farmers Home Administration
grants might also be available or installation of ultra-low-flow toilets
as part of the Limited Action Alternative.
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IMPACT MATRIX
IMPACT
CATEGORY
IMPACTED
AREA
Surface Water
Quality
Nutrient Loads
Non-Point Source
Runoff
IMPACT
TYPE & DEGREE
Primary;
Long-Term
Primary;
Short-Term
Secondary;
Long-Term
DESCRIPTION
OTTER LAKE. DEER LAKE, WALKER LAKE. LONG LAKE. AND LAKE BLANCHE
Ml Alternatives:
None of the alternatives will have a significant Impact on
phosphorus loading since a small percentage of the load comes
from on-slte systems as compared to non-point sources and tributaries.
The trophic status of all these lakes is anticipated to remain the
same.
ROUND LAKE
No Action Alternative, Alternative 1:
Phosphorus loads will significantly Increase over the planning
period but the increased load is not anticipated to change the
trophic status of Round Lake since the current nutrient load is
very low.
Limited Action Alternative:
Septic leachate to Round Lake would be minimized by collecting
black uater in holding tanks. This could eliminate 90t of the
nitrogen load and 75% of the phosphorus load under the phosphorus
ban (40% of the phosphorus load without).
Alternatives 2, 3, 4^_X and Facility Plan Proposed _Actlo_n:
Nutrient load would be substantially reduced by providing
centralized collection and treatment system, but the trophic
status of Round Lake would not change.
No Action Alternative^
This alternative would involve no construction and no corresponding
Increase in erosion and sedimentation.
Limited Action:
This alternative Involves little construction and consequently
Increased non-point source runoff will be minimal.
Alternatives 1. 2. 3, 4, 5, and Proposed Action:
A temporary increase in soil erosion and sedimentation may occur
as a result of sewering, with Increased loads being proportional to
the area sewered.
No Action and Limited Action:
Induced growth above the baseline projections is unlikely and
therefore little increase in non-point source runoff is anticipated.
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IMP AC T MATRIX
(Continued)
IMPACT
CATEGORY
IMPACTED
AREA
IMPACT
TYPE 4 DEGREE
DESCRIPTION
Shoreline
Eutrophlcation
Groundwater
Groundwatrr
Quantity
Primary;
Long-Tenn
Primary;
Long-Term
Secondary;
Long-Term
Alternatives &, 5, and Facility Plan Proposed Action:
Induced growth Is likely to be greatest with these alternatives
and growth will be concentrated in shoreline areas. This may
result in Increased non-point source runoff. The increase would
be small in relation to total non-point source loads from the
entire watershed.
Alternatives 1, 2, and 3:
Increase in non-point source loads are less with less extensive
sewering.
Ho Action:
Although algal growth is currently sparse along most shoreline
areas, growth could potentially increase over the planning period
as use of on-site systems increases. Algal growth from use of
ST/SAS is a subject of on-going study at Otter Tail Lake.
Limited Action:
The potential for shoreline eutrophicatIon Is substantially
reduced by eliminating black water discharge in areas with a
high groundwater flow rate.
Alternatives 1. 2, and 3:
Would reduce nutrient loads from septic tanks. However, some
on-site systems would continue to leach nutrients which could
contribute to algae growth (needs further investigation).
Alternatives A, 5. and Facility Plan Proposed Action:
Would have the greatest potential for minimizing lakeshore
eutrophlcatlon by eliminating septic tanks as a nutrient source.
Alternative 5:
Alternative 5 would eliminate groundwater recharge In the
Study Area but failure to return wastewater flows to groundwater
would result In negligible loss.
All Alternatives:
Increased use of aquifer would result In minimal depletion of
yield.
All Alternatives:
Loss of aquifer recharge areas as a result of development of
Impervious surface cover would be minimal.
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IMPACT MATRIX
(Continued)
IMPACT
CATEGORY
IMPACTED
AREA
IMPACT
TYPE & DECREE
Groundwater
Quality
Primary;
Long-Term
Environmentally
Sensitive
Areas
Wetlands
Primary;
Short-Term
or
Long-Term
DESCRIPTION
No Ac tIon:
This alternative has the greatest potential for groundvater
contamination with nitrates and for leaching of septic tank
nutrients to Otter Tail Lake.
Limited Action Alternative:
Alternatives 1, 2, and 3:
Continued leaching of phosphorus from ungewered areas would be a
potential nutrient source for localized algal growth. Potential
for groundwater contamination with nitrates also exists in unsewered
areas. On-site maintenance and upgrade would reduce the potential
for both Impacts.
Alternatives 1, 2, 3, and 6:
Potential for groundwater contamlnnt Inn Vty nttr.ites is minimal with
land application. Discharge of renovated wastewater from rapid
infiltration (Alternative 1 and 2 only) will not significantly
Increase nutrient load to Otter Tail Lake, but may lead to localized
algal growth.
Alternative 5:
Eliminates potential for groundwater contamination from domestic
wastewater.
No Action and Limited Action:
No wetland areas would be Impacted.
Alternative 1:
Wetlands along the south shore of Otter Tail Lake between Lake
Blanche and Otter Tail Lake would be Impacted by Increased
sedimentation and modified water circulation patterns during
construction of sewers.
Alternative 2:
In addition to wetlands Impacted by Alternative 1, wetland areas
along the banks of the Otter Tall River and In low lying areas
of Amor Park would be impacted.
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I M P A C_T MATRIX
(ConeInued)
IOTACT
CATEGORY
IMPACTED
AREA
IMPACT
TYPE & DEGREE
DESCRIPTION
Secondary;
Long-Term
Floodplains
Primary;
Short-Term
Steep Slopes
Primary;
Short-Term
Alternatives 3,
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IMPACT MATRIX
(ConeInued)
IMPACT
CATEGORY
IMPACTED
AREA
IMPACT
TYPE 4 DECREE
DESCRIPTION
Environmentally
Sensitive
Areas (Cont'ct).
Population
Prime Agricultural
Lands
Forest Land
Rate of Growth
Secondary;
Long-Term
Primary and
Secondary
Primary;
Short-Term
Secondary;
Long-Term
Secondary;
Long-Term
All Alternatives:
Development Is likely to continue on steep slopes, but these areas
are rare.
All Alternatives:
No impact on prime agricultural lands-
No Action and Limited Action Alternatives:
No Impact on forest land above that projected for baseline
population.
Alternatives 1, 2, 3. A, 5, and Proposed Action:
Collection systems will be constructed through forested areas but
these Impacts will be minimal.
No Action and Limited Action Alternatives:
No development of forest land above that projected for baseline
population.
Alternatives 1. 2, and 3:
Minimal development of forested land.
Alternatives <*, 5, and Facility Plan Proposed Action:
About 15 to 25 acres of forest land would be developed in addition
to acreage needed to accomodate the baseline population.
No Action and Limited Action Alternatives:
Growth is anticipated to be similar to baseline projections.
Alternative 1:
Growth anticipated to Increase 32 above baseline projections.
Alternatives 2 and 3:
Growth anticipated to increase 6% above baseline projections.
Alternatives 6, 5, and Facility Plan Proposed Action:
Anticipated to Induce up to 9Z additional growth above baseline
projec tIons.
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IMPACT MATRIX
(Continued)
IMPACT
CATEGORY
IMPACTED
AREA
IMPACT
TYPE 4 DEGREE
DESCRIPTION
Land Use
Developable
Acreage, Growth
Patterns
Local Economy
Community Composition
and Character
Financial Burden
Secondary;
Long-Term
Secondary;
Long-Terra
Secondary;
Long-Tenn
Ho Action and Limited Action Alternatives:
Land development is expected to be similar to that needed to
accomodate the baseline projection.
Alternative 1:
Development of residential land will be increased by 15 to ^9
above that needed to accomodate baseline population. Development
will continue in single tier pattern along shoreline areas.
Alternatives 2 and 3:
Development would be Increased by 25 to 30 acres. Higher density
shoreline development would result but little second tier
development is anticipated.
Alternatives 4, 5, and Facility Flan Proposed Action:
Land development would be Increased by about 50 acres. High density
shoreline development would result in some segments, but little
second tier development is likely.
No Action Alternative:
Community composition will remain as is.
Limited Action, Alternative 1. and 2:
Some loss of lower income population base due to displacement
pressure.
Alternatives 2, 3, 4, 5, and Proposed Action:
Moderate to severe change in community composition by loss of lower
income population.
No Action Alternative:
No increased financial burden for collection and treatment of
wastewater.
Limited Action Alternative, and Alternative 1:
Financial burden would be placed on 30-40% of permanent population.
Alternative 2:
40-50% of the population would feel a financial burden from local
costs.
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IMPACT MATRIX
(Continued)
IMPACT
CATEGORY
IMPACTED
AREA
IMPACT
TYPE & DEGREE
DESCRIPTION
Displacement
Pressure
Cultural Resources
Archaeological and
Historical Sites
Secondary;
Long-Term
Primary;
Short-Term
& Long-Term
Secondary;
Short-Term
& Long-Term
Alternatives 3 and 4;
Financial burden would be placed on 50-60% of the permanent
population.
Alternative 5 and Proposed Action:
The financial burden would impact the largest percentage of the
population with these alternatives. 60-702 of the population
would be financially impacted.
No Action Alternative;
No population would be displaced as a result of wastewater
collection and treatment costs.
Limited Action:
8-121 of the population would face displacement pressures.
Alternatives 1 and 2:
10-152 of the population would face displacement pressures.
Alternatives 3 and A:
20-302 of population would face displacement pressures.
Alternative 5 and Proposed Action:
30-40% of population may be displaced by the costs of these
alternatives.
No Action and Limited Action Alternatives:
These alternatives would not impact archaeological and historical
sites.
Alternatives 1» 2( 3, A, S, and Proposed Action:
All alternatives could possibly have an impact upon identified and
unidentified archaeological and historical sites. An archaeological
survey of the Study Area will take place upon the selection of the
wastewater management alternative. At that point, the primary and
secondary impacts of the project on these sites could be addressed
in more detail.
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CHAPTER VI
CONCLUSIONS AND RECOMMENDATIONS
A. INTRODUCTION
As discussed in Section I.D.I, EPA has several possible courses of
action based on this EIS's review of the Facility Plan Proposed Action.
The Agency may:
Approve the original grant application, possibly with recom-
mendations for design changes and/or measures to mitigate
impacts of the Facility Plan Proposed Action;
Return the application with recommendations for additional
Step I analysis;
With the applicant's and State's concurrence, approve Step II
funding for an alternative to the Facility Plan Proposed
Action; or
Reject the grant application.
The choice of one of the above options depends upon how the Alter-
natives in the EIS compare to the Facilities Plan Proposed Action.
B. SUMMARY OF EVALUATION
Four primary criteria were used in selecting the EIS Recommenda-
tion: costs, impact, reliability, and flexibility. Within each category
several factors were compared; cost factors for example, included
present worth, user charges, and total 1980 private costs. Impacts
which EPA considers to be decisive in selection of an alternative are
identified and considered. Alternatives reliability is measured against
centralized collection and treatment as the standard.
The relationship between the alternatives and the criteria used to
evaluate them are easily visualized in a matrix. A matrix relating
alternatives to environmental impacts is presented in Section V.F.
Table VI-1 presents a matrix summarizing the relationship between al-
ternatives and their costs, environmental impacts, reliability and
flexibility.
Table VI-1 also ranks the alternatives according to their total
present worth. This ranking has two purposes:
Costs are easily quantifiable, perhaps the least subjective
measure of value.
EPA Construction Grants regulations require selection of the
most cost-effective alternative, that is, the alternative
meeting project goals with the least total present worth and
with acceptable environmental and socioeconomic impacts.
177
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Table VI-]
ALTERNATIVE SELECTION MATRIX*
Alternative
EIS
Alternative 4
M
09
Present
Worth
(xl.OOO)
11,336.0
User
Charges
260
One Time
Household
Charge
Gravity
Severs ,
about
S1000/
Household
Surface
Mater Qual ity
Impacts
Decreased nutrient
load to Otter Tall
Lake resulting
from elimination
of septic tanks Is
not likely to have
a significant
effect on water
quality;
Significant de-
crenoe In nutrient
loac to Round Lake
but trophic status
Is not likely to
change;
Tributaries and
precipitation con-
tinue to be the
most significant
sources of nutri-
ents for all
lakes;
Potential for
shoreline eutro-
phlcatlon result-
ing In algae
growth Is sharply
decreased;
Land application
sites may dis-
charge low nutri-
ent loads to
surface waters.
Croundwater
Impacts
Significant reduction
of nitrate and phos-
phorus levels dis-
charging to surface
waters. Eliminates
septic tanks as a
potential source of
nutrients.
Environmental ly
Sensitive
Areas
Construction
impacts on
wetlands are
unavoidable;
Long- term
impacts are
minimal with
only a slight
increase in
development
of wetland
acreage .
Populat ion
Impacts
Population
Increase
of 91
above
basel Ine
projec-
tions
Land
Use
Increases
developable
acreage by
50 acres
above base-
line pro-
ject ions;
Slight In-
crease in
density of
shoreline
development
Financial
Burden
W-60T
THsplacement
Pressure
20-30*
Flexibility
High Commitment
limited flexib-
ility because of
existing sever-
ing. Two land
application
sites provide
for more flex-
ibility than
Facility Plar
Proposed Action.
Reliability
Vse of pressure
the reliability
of this alterna-
tive sonevhat
compared to
Facility Plan
Proposed Action
Reliability
better than
EIS 3-
*Alten.atlves are listed in order of present worth.
-------
Table VI-1 (Continued)
Alternative
EIS
Alternative 3
Facility Plan
,_,
-j
SC
EIS
Alternative 5
EIS
Alternative 2
Present
Worth
(xl.OOO)
10,539.6
10,358.6
10,245.7
10,202.8
User
Charges
240
350
375
210
One Time
Household
Charge
Gravity
Sewers,
about
$10007
Household
Gravity
about
S1000/
Household
Gravity
about
S1000/
Household
Gravity
Sewers,
about
SIOOO/
Household
Surface
Water Quality
Impacts
Same as Alternative
4 except the poten-
tial for shoreline
eutrophlcatlon Is
higher because sep-
tic tanks i-tlll
serve southeast
shore. Upgrade and
maintenance of on-
slte systems will
reduce shoreline
eutrophicat Ion
potential.
Similar to EIS 4
wr&nt tYia t rh*> In 1
application sice on
the south shore of
Otter Tail Lake
would be eliminated.
thereby eliminating
this source of
nutrients to Otter
Tail Lake.
Similar to Facility
PI an P n «pH
Ac t ion .
Continued reliance
on septic tanks on
the northwest and
southwest shores ;
Septic leachate
will continue to
discharge to Otter
Tall Lake along
these shorelines;
Increased poten-
tial for shoreline
eutrophlcation as
compared to EIS
Alternatives 3, 4,
5, and Proposed
Action .
Croundwater
Impacts
Greatly minimizes the
potential for ground -
water contamination
with nitrates, and
groundwater discharge
of phosphorus to sur-
face water, but does
not eliminate on-site
systems as a poten-
tial nutrient source.
Similar to EIS Altern-
. i .
wastewater would be
applied to one land
application site only.
Eliminates soil treat-
. , ,
tanks and land appli-
catlon) as a source of
grounduater contamina-
tion.
Potential exists for
nitrate contamination
of groundwater in un-
sewered areas , but
on-site maintenance &
upgrade will decrease
this potential Impact;
Groundwater continues
to discharge septic
leachate to Otter Tall
Lake in unsewered
areas .
Environmental ly
Sensic Ive
Areas
Con Ft ruction
impacts are
unavailable
but impact
less acreage
than Alterna-
tive /. .
Similar to EIS
V . . ,
except an addi-
tional wetland
area (Segment
27) would be
impacted.
S a me a s
A 1 * /
Similar to
Alternative 3
Populat Ion
Impacts
Populat ion
increase
of 6Z
above
basel Ine
projec-
tions.
Same as
. « .,
tlve 4
Same as
Air
tlve 4
Same as
Alterna-
five 3
I.nnd
Use
25-30 acres
less In-
crease In
shoreland
development
than Alterna-
tive 4.
Same as
. .
tlve 4
Same as
A 1
tlve A
Same as
Alterna-
tlve 3
Financial
Burden
50-602
60-702
60-70%
40-50Z
Displacement
Prpssuro
20-30?
30-402
30- /.or.
10-155!
Flexibility
HJjtJj flexibility
for future
change and
expansion .
Involves an
.
mitment of re-
sources; reduces
flexibility for
future planning;
Innd appl icat ion
site could bo
expanded east Iv
to accommoHa tc
add it lona 1 f low.
Ext ens I ve com-
. .
sources an«?n F.IS ?
and EIS '« bo-
cause of f ntor
mediate use of
central Ized
sewer ing.
Use of gravl ty
this the most
reliable alter?. -
at Ivc. Pump
stations d«?cre is«»
reliability so"'c-
wha t because o?
chance of fni V. re
Same -is Far i 1 1 r y
_
Act ton.
Reliability
Intermediate
between EIS
Alternatives 1
and 3.
-------
Table VI-1 (Continued)
Alternative
EIS
Alternative \
Limited Actlc-n
Alternative
Present
Worth
(xl ,000)
9,306.8
7,152.2
User
Charges
175
165
One Time
Household
Charge
Gravity
Sewers,
about
S1000/
Household
Surface
Water Quality
Impacts
Continued dis-
charge of aeptic
leachate along all
but southwest
shore of Otter
Tall;
Septic leachate
is unJJJteJv to
significantly
impact surface
water quality
since septic
leachate is a
small source of
total nutrient
load:
Continued dis-
charge o( septic
leachate to Round
Lake will substan-
tially Increase
the total nutrient
load but is not
likely to effect
trophic status.
By collecting black
water In holding
tanks, the major
source of nitrogen
and the major source
of phosphorus (pro-
vided the phosphorus
ban Is In effect)
would be elinlnated
from septic leachate.
Groundwater
Impacts
Potential exists for
grounivater contam-
ination In unsewered
areas but on-slte
maintenance and up-
grade would sharply
decrease this poten^
tlal;
Groundwater contin-
ues rp discharge
septic leachate to
Otter Tall Lake,
Bound Lake, and
Deer Lake.
Collecting black water
In holding tanks would
minimize the potential
for groundwater con-
tamination by nitrates
and would minimize
leaching of phosphorus
from septic tanks to
surface water.
Environmentally
Sensitive
Areas
Construction
Impacts only
on wetlands
between Otter
Tall Lake and
Lake Blanche.
Wetlands would
be minimally
impacted.
Population
Impacts
Population
Increase
of 3Z
above
baseline.
Population
similar to
hasel Ine
projec-
t ions
Land
Use
15-20 acres
minim] In-
crease in
development
density.
Development
similar to
baseline
projections.
Financial
Burden
35-40X
33-387
Displacement
Pressure
10-I5X
8-12*
Flexibility
High flexibility
for future plan-
ning and design
changes.
High flexibility
for future plan-
ning and design
changes.
Reliability
Extensive use of
cluster systems
and on-slte sys-
tems, together
vlth pressure
sewers gives
this alternative
low reliability.
On-sltc portion
has good reli-
ability In case
of civil or
energy emergency.
o
CO
Complete decen-
tralization
using grey
water/black
t ion and con-
ventional ST/
SAS gives this
alternative lower
reliability than
any of those
listed- Greatest
reliability of
any alternative
or energy
*iraergenc;' -
-------
Selection of the cost-effective alternative requires identification
of trade-offs between costs and other criteria. The evaluation factors
included with total present worth in Table VI-1 are those EPA has deter-
mined to be most important in identifying trade-offs for this project.
C. CONCLUSIONS
Information gathered during the preparation of this EIS has pro-
vided the following insights regarding the status of existing systems:
There was nearly a one-to-one relationship between permanent
residences and septic leachate plumes discharging to Otter
Tail Lake during an April 1979 survey.
Groundwater and the septic tank leachate which it carries
discharge into Otter Tail Lake along all but the western
shore. Groundwater (and septic tank leachate) flow is par-
ticularly rapid along the Otter Tail shoreline adjacent to
Walker Lake, Long Lake, Lake Blanche and the Otter Tail River.
Consequently nutrient breakthrough to the surface waters is
strongest along the shorelines of the small surrounding lakes.
Despite the large number of on-site systems discharging to
Otter Tail Lake, the total nutrient contribution from this
source is small in comparision to nutrient loads from tribu-
taries and precipitation.
Localized well water contamination has been observed in wells
sampled along the northeast and southeast shores. Contamina-
tion is neither widespread nor directly attributable to the
operation of existing on-site systems; it does not fit any
pattern of system problems or location.
Surface malfunctions of three septic systems were observed in
the Proposed Service Area by field verification of aerial
photographs.
Most of the on-site systems in use within the Proposed Service Area are
poorly maintained and many are inadequately designed based upon criteria
established by the Shoreland Management Ordinance for design of on-site
systems. A sanitary survey is currently underway to determine the
extent of non-compliance with the sanitary code and whether or not such
violations have resulted in problems with on-site systems.
While existing on-site systems do not degrade water quality of the
whole lake, localized water quality impacts may be occurring. Localized
impacts of greatest concern are elevated nitrate concentrations in
groundwater used for drinking water anil near-shore aquatic plant growth
stimulated by excessive breakthrough of phosphorus. Neither the Facili-
ty Plan nor field work conducted to date for the EIS have conclusively
documented the magnitude or locations of near shore aquatic plant
growth. Well water samples taken to date show localized contamination
but this survey is not yat complete. Final selection of a recommended
181
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alternative is, therefore, contingent upon the results of field studies
planned for July through September 1979.
A comparison of the impacts of the various alternatives provides a
basis for the following conclusions considered in selecting an alterna-
tive.
The population in the Proposed Service Area would increase by a
maximum of 9% with the most centralized EIS alternatives. The more
centralized wastewater treatment systems will allow for higher density
development along some shoreline segments but much of the shoreline is
already considered developable without provisions for centralized treat-
ment. Second tier development is not anticipated because more attrac-
tive shoreline sites are available along nearby lakes.
The surface water quality and trophic status of all lakes in the
Proposed Service Area is not anticipated to change as the result of
implementing any wastewater alternative. Limited benefits to water
quality result with the centralized alternatives because of the small
contribution of septic tanks to the total nutrient load.
Centralized wastewater treatment would eliminate septic tanks as a
source of u oundwater pollution. The extent to which existing on-site
systems are contributing to groundwater pollution, is the subject of an
ongoing survey which will be completed by September 1979. Groundwater
contamination could be minimized by implementing the Limited Action
Alternative as up to 90% of the nitrogen could be eliminated from sub-
surface disposal under this alternative.
The decentralized Limited Action Alternative has a total present
worth 31% less than that of the Facility Plan Proposed Action. EIS
Alternative 1 which provides sewers for only a small segment of the
south shore, has a total present worth 10% less than the Facility Plan
Proposed Action.
The difference in user charges between the Facility Plan Proposed
Action and the Limited Action or EIS Alternative 1 is even more signifi-
cant. EIS Alternative 1 would have an annual user charge half that of
the Facility Plan Proposed Action, ami the Limited Action Alternative
would have even lower user charges (47°/0 of the Facility Plan Proposed
Action). The significance of the difference in the annual user charges
can be easily understood by determining the financial burden and dis-
placement pressure of the various alternatives. These determinations
are shown in Table Vl-1. In addition both the Limited Action Alter-
native and EIS Alternative 1 would totally or largely eliminate
individual private costs for sewer hookup.
The No Action Alternative is not recommended for the following
reasons:
There are some problems with on-site systems in the remainder
of the Proposed EIS Service Area which should be addressed
through monitoring, improved maintenance of the existing and
future systems, residential water conservation, and renovation
or replacement of existing systems.
182
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Improved surveillance and regulation of on-site systems in the
Proposed Service Area is justified to maintain its unique
scenic and recreational values.
The Limited Action Alternative, as well as the partially decentralized
EIS Alternatives 1, 2, and 3 would require that the problems with
on-site systems be corrected through a program to upgrade and repair
on-site systems.
D. DRAFT EIS RECOMMENDATION
The Limited Action Alternative is the Recommended Action of this
Draft EIS. The recommendation is tentative and requires verification of
preliminary findings by studies which will be completed during the
summer of 1979. The Limited Action Alternative was selected on the
basis of its cost-effectiveness and as the result of the following
preliminary findings and assumptions:
Septic leachate discharges to Otter Tail Lake were observed
with high frequency in areas with high groundwater flow rates.
Elimination of subsurface disposal of black water in these
areas would significantly increase the nutrient load from
on-site systems.
On-site systems are not known at this time to be contributing
to widespread alage growth, or well water contamination or to
lake eutrophication and the need for centralized collection
and treatment has not been demonstrated.
Because of new or unforeseen information that could be turned up
during the additional water quality studies or the detailed Step II
design work, EIS Alternative 1 should be retained as a contingent
"backup" alternative. Its environmental impacts, its local costs, and
its on-site upgrading proposals are virtually identical with the Limited
Action Alternative. It is also important to note that grey water/black
water separation achieves a high phosphorus reduction rate only where a
detergent phosphorus ban is in effect or where washing machines are not
used.
In order to verify or modify this recommendation, EPA will conduct
additional field studies including:
Resident interviews, lot surveys and well inspections for a
representative sample of dwellings in the Proposed Service
Area.
Resurvey of the lakes for septic leachate discharge using
continuous scanning techniques under summer conditions.
Detailed analysis of nutrient transport and aquatic plant
growth for selected shoreline sites.
Based on these studies the Limited Action Alternative or some degree of
off-site treatment like that included in EIS Alternative 1, may be found
necessary.
183
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E. IMPLEMENTATION
While the additional studies are being completed in August timely
action by Otter Tail County can ensure quick processing of the Step II
application. It is recommended that the County establish a small waste
flows district encompassing at least the Proposed Service Area.
Guidance for development of this district is included in Section
III.E.2. Specific aspects of implementing the Draft EIS Recommended
Action are discussed below.
1. COMPLETION OF STEP I (FACILITIES PLANNING) REQUIREMENTS
FOR THE SMALL WASTE FLOWS DISTRICT
For timely releast of Step 2 funds for any decentralized Alter-
native, the applicant would first need to:
Certify that construction of the project and the operation and
maintenance program will meet local, State and Federal re-
quirements. Because many existing systems do not conform with
the Shoreland Management Ordinance, the variance procedures
outlined in the Ordinance may have to be utilized for certain
systems. The environmental, engineering and economic basis
L^^ granting variances should be developed with State input,
probably on an ad hoc basis during Step II site analysis and
design. In regard to non-conforming on-site systems, notice
of intent to develop local guidance for granting variances
will be sufficient for Step I certification (see also Section
VI.E.3 below.)
Obtain assurance of unlimited access to each individual system
at all reasonable times for such purposes as inspections,
monitoring, construction, maintenance, operations, rehabili-
tation and replacement.
Plan for a comprehensive program of regulation and inspection
for individual systems.
2. SCOPE OF STEP II FOR THE SMALL WASTE FLOWS DISTRICT
A five step program for wastewater management in small waste flows
districts was suggested in Section III.E.2. The first three would
appropriately be completed in Step II. These are:
Develop a site-specific environmental and engineering data
base;
Design the Management Organization; and
Agency start-up.
EPA will assist the applicant in defining specific objectives and
tasks for Step II work.
184
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3. COMPLIANCE WITH STATE AND LOCAL STANDARDS IN THE SMALL
WASTE FLOWS DISTRICT
As discussed in Section II.C. many existing on-site systems do not
conform to current design standards for site, design or distance from
wells or surface waters. For some systems, such as those with under-
sized septic tanks, non-conformance c;m be remedied relatively easily
and inexpensively. In other cases the remedy may be disruptive and
expensive and should be undertaken only where the need is clearly
identified. Data on the effects of existing systems indicate that many
existing non-conforming systems, and future repairs that still may not
conform to design standards, may operate satisfactorily. Where com-
pliance with design standards is 1) unfeasible or too expensive and 2)
site monitoring of ground and surface waters shows that acceptable
impacts are attainable, then a variance procedure to allow renovation
and continued use of non-conforming system is recommended. Decisions to
grant variances should be based on site-specific data or on a substan-
tial history of similar sites in the area.
This does not mean that state or county standards should simply be
discarded. All decentralized alternatives project a substantial level
of on-site system repair and upgrading. The variance procedures might
be appropriate for the residents of systems that either (a) cannot be
upgraded to compliance with state or local standards and (b) are not
causing any discernable water quality problems.
Local and State decisions on variance procedures would likely be
influenced by the degree of authority vested in the small waste flows
district. If the district has the authority and sufficient financial
means to correct errors, plus the trained personnel to minimize errors
in granting variances, variance procedures may be more liberal than
where financial and professional resources are limited. Higher local
costs, caused by unnecessary repairs or abandonment of systems would be
expected to result from very conservative or no variance guidelines.
Conversely, ill-conceived or improperly implemented variance procedures
would cause frequent water quality problems and demands for more expen-
sive off-site technologies.
4. OWNERSHIP OF ON-SITE SYSTEMS SERVING SEASONAL RESIDENCES
Construction Grants regulations allow Federal funding for 1) reno-
vation and replacement of publicly owned on-site systems serving
permanent or seasonally occupied residences, and 2) of privately owned
on-site systems serving permanent residences. Privately owned systems
serving seasonally occupied residences are not eligible for Federally
funded renovation and replacement.
Depending upon the extent and costs of renovation and replacement
necessary for seasonal residences, the municipalities or a small waste
flows district may elect to accept ownership of the on-site systems.
Rehabilitation of these systems would then be eligible for Federal
assistance, and local costs for seasonal residents would be dramatically
reduced.
185
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Under EPA Program Requirements Memorandum 79-8, however, an
easement giving the District access to an control of on-site systems
would be considered tantamount to public ownership --without an actual
transfer of property.
186
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CHAPTER VII
THE RELATIONSHIP BETWEEN SHORT-TERM USE
AND LONG-TERM PRODUCTIVITY
A. SHORT-TERM USE OF THE STUDY AREA
Otter Tail Lake has been and will continue to be used as a
residential/recreational area. Disturbance of the site by routine
residential/recreational activities will continue regardless of which
alternative is implemented.
B. IMPACT UPON LONG-TERM PRODUCTIVITY
1. COMMITMENT OF NON-RENEWABLE RESOURCES
The pressure for development in the Proposed Service Area would
increase slightly as the result of implementing the Facility Plan
Proposed Action, or the other centralized alternatives. Filling-in of
available shoreline areas would occur to a lesser extent under the
Recommended Alternative of this EIS.
Non-renewable resources associated with any of the wastewater
treatment scenarios would include concrete for construction. Con-
sumption of electric power by pumps would be associated to varying
degrees with all actions except the Recommended Alternative of this EIS.
Manpower would also be committed to the construction, operation and
management of new or rehabilitated facilities.
2. LIMITATIONS ON THE BENEFICIAL USE OF THE
ENVIRONMENT
Neither the Proposed Action nor the Recommended Action will have
any significant effect on beneficial use of the environment. The
implementation of a centralized wastewater management plan may increase
the current level of recreational activity slightly through induced
near-shore development, but most of the shoreline would be developable
even under the No Action Alternative.
187
-------
188
-------
Chapter VIII
IRREVERSIBLE AND IRRETRIEVABLE COMMITMENT OF RESOURCES
Those resources associated with construction and maintenance of
wastewater systems would be committed. These were discussed in Section
VI.B.I.
In addition the growth expected in the Study Area would require a
commitment of resources to the construction of new dwellings,
construction or improvement of roads, and facilities associated with
water sports. Besides construction materials, such as lumber, steel,
concrete and glass, electricity and manpower would also be committed to
new development.
Human resources would include construction personnel and, perhaps
infrastructural personnel to service the added community needs.
189
-------
190
-------
CHAPTER IX
PROBABLE ADVERSE IMPACTS WHICH CANNOT BE AVOIDED
If the action proposed by the Facilities Plan were implemented,
some destruction of terrestrial habitat would result from construction
of new dwellings. The Recommended Action would not induce significant
development above that projected to accommodate the baseline population.
Construction of sewage lagoons or new sewer lines would disturb the
soil, resulting in sediment runoff. This runoff would cause a temporary
increase in siltation in both streams and offshore areas. This type of
runoff can also be caused by the extensive excavation required during
upgrade or rennovation of on-site septic systems and off-site cluster
systems.
191
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192
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GLOSSARY
ACTIVATED SLUDGE PROCESS. A method of secondary wastewater treatment in
which a suspended microbiological culture is maintained inside an
aerated treatment basin. The microbial organisms oxidize the com-
plex organic matter in the wastewater to simpler materials, and
energy.
ADVANCED WASTE TREATMENT. Wastewater treatment beyond the secondary or
biological stage which includes removal of nutrients such as phos-
phorus and nitrogen and a high percentage of suspended solids.
Advanced waste treatment, also known as tertiary treatment, is the
"polishing stage" of wastewater treatment and produces a high
quality of effluent.
AEROBIC. Refers to life or processes that occur only in the presence of
oxygen.
ALGAL BLOOM. A proliferation of algae on the surface of lakes, streams
or ponds. Algal blooms are stimulated by phosphate enrichment.
ALKALINE. Having the qualities of a base, with a pH of more than 7.
ALLUVIAL. Pertaining to material that has been carried by a stream.
ALTERNATIVE TECHNOLOGY. Alternative waste treatment processes and
techniques are proven methods which provide for the reclaiming and
reuse of water, productively recycle waste water constituents or
otherwise eliminate the discharge of pollutants, or recover energy.
Alternative technologies may not be variants of conventional bio-
logical or physical/ chemical treatment.
AMBIENT AIR. The unconfined portion of the atmosphere; the outside air.
ANAEROBIC. Refers to life or processes that occur in the absence of
oxygen.
AQUATIC PLANTS. Plants that grow in water, either floating on the
surface, or rooted emergent or submergent.
AQUIFER. A geologic stratum or unit that contains water and will allow
it to pass through. The water may reside in and travel through
innumerable spaces between cock grains in a sand or gravel aquifer,
small or cavernous openings formed by solution in a limestone
aquifer, or fissures, cracks, and rubble in such harder rocks as
shale.
ARTESIAN AQUIFER. A water-filled layer that is sufficiently compressed
between less permeable layers to cause the water to rise above the
top of the aquifer. If the water pressure is great, water will
flow freely from artesian wells.
193
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ARTESIAN WELL. A well in which, flow is sustained by the hydrostatic
pressure of the aquifer. See Artesian Aquifer.
BACTERIA. Any of a large group of microscopic plants living in soil,
water or organic matter, important to man because of their chemical
effects as in nitrogen fixation, putrefaction or fermentation, or
as pathogens.
BAR SCREEN. In wastewater treatment, a screen that removes large float-
ing and suspended solids.
BASE FLOW. The rate of movement of water in a stream channel which
occurs typically during rainless periods when stream flow is main-
tained largely or entirely by discharges of groundwater.
BASIC USAGE. Those functions that small waste flow districts would be
required to perform in order to comply with EPA Construction Grants
regulations governing individual on-site wastewater systems.
BEDROCK. The solid rock luneath the soil and subsoil.
BIOCHEMICAL OXYGEN DEMAND (BOD). A measure of the amount of oxygen
consumed in the biological processes that decompose organic matter
in Wetter. Large amounts of organic waste use up large amounts of
dissolved oxygen; thus, the greater the degree of pollution, the
greater the BOD.
BIOMASS. The weight of living matter in a specified unit of environ-
ment. Or, an expression of the total mass or weight of a given
population of plants or animals.
BIOTA. The plants and animals of an area.
BOD-. See "Biochemical Oxygen Demand." Standard measurement is made
for 5 days at 20°C.
BOG. Wet, spongy land; usually poorly drained, and rich in plant
residue, ultimately producing highly acid peat.
CAPITAL COSTS. All costs associated with installation (as opposed to
operation) of a project.
CAPITAL EXPENDITURES. See Capital Costs.
CHLORINATION. The application of chlorine to drinking water, sewage or
industrial waste for disinfection or oxidation of undesirable
compounds.
COARSE FISH. See Rough Fish.
COLIFORM BACTERIA. Members of a large group of bacteria that flourish
in the feces and/or intestines of warm-blooded animals, including
man. Fecal coliform bacteria, particularly Escherichia coli (E.
coli), enter water mostly in fecal matter, such as sewage or feed-
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lot runoff. Coliform bacteria apparently do not cause serious
human diseases, but these organisms are abundant in polluted waters
and they are fairly easy to detect. The abundance of coliform
bacteria in water, therefore, is used as an index to the proba-
bility of the occurrence of such diease-producing bodies (patho-
gens) as Salmonella, Shigella, and enteric viruses. These path-
ogens are relatively difficult to detect.
COLIFORM ORGANISM. Any of a number of organisms common to the intes-
tinal tract of man and animals whose presence in wastewater is an
indicator of pollution and of potentially dangerous bacterial
contamination.
CQMMINUTQR. A. machine that breaks up wastewater solids.
CONNECTION FEE. Fee charged by municipality to hook up house connection
to lateral sewer.
CUBIC FEET PER SECOND (cfs). A measure of the amount of water passing a
given point.
CULTURAL EUTROPHICATION. Acceleration by man of the natural aging
process of bodies of water.
DECIDUOUS. The term describing a plant that periodically loses all of
its leaves, usually in the autumn. Most broadleaf trees in North
America and a few conifers, such as larch and cypress, are decid-
uous.
DECOMPOSITION. Reduction of the net energy level and change in chemical
composition of organic matter by 'action of aerobic or anaerobic
microorganisms. The breakdown of complex material into simpler
substances by chemical or biological means.
DETENTION TIME. Average time required for water to flow through a
basin. Also called retention time. Or, the time required for
natural processes to replace the entire volume of a lake's water,
assuming complete mixing.
DETRITUS. (1) The heavier mineral debris moved by natural watercourses
(or in wastewater) usually in bed-load form. (2) The sand, grit,
and other coarse material removed by differential sedimentation in
a relatively short period of detention. (3) Debris from the decom-
position of plants and animals.
DISINFECTION. Effective killing by chemical or physical processes of
all organisms capable of causing infectious disease. Chlorination
is the disinfection method commonly employed in sewage treatment
processes.
DISSOLVED OXYGEN (DO). The oxygen gas (Oj dissolved in water or sew-
age. Adequate oxygen is necessary for maintenance of fish and
other aquatic organisms. Low dissolved oxygen concentrations
sometimes are due to presence, in inadequately treated wastewater,
of high levels of organic compounds.
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DRAINAGE BASIN. (1) An area from which, surface runoff is carried away
by a single drainage system. Also called catchment area, water-
shed, drainage area. (2) The largest natural drainage area sub-
division of a continent. The United States has been divided at one
time or another, for various administrative purposes, into some 12
to 18 drainage basins.
DRAINAGEWAYS. Man-made passageways, usually lined with grass or rock,
that carry runoff of surface water.
DRYWELL. A device for small installations, comprising one or more pits
extending into porous strata and lined with open-jointed stone,
concrete block, precast concrete or similar walls, capped, and
provided with a means of access, such as a manhole cover. It
serves to introduce into the ground, by seepage, the partly treated
effluent of a water-carriage wastewater disposal system.
EFFLUENT. Wastewater or other liquid, partially or completely treated,
or in its natural state, flowing out of a reservoir, basin, treat-
ment plant, or industrial plant, or part thereof.
EFFLUENT LIMITED. Any stream segment for which it is known that water
quality will meet applicable water quality standards after com-
liance with effluent discharge standards.
ELEVATED MOUND. A mound, generally constructed of sand, to which
settled wastewater is applied. Usually used in areas where con-
ventional on-site treatment is inadequate.
ENDANGERED SPECIES (FEDERAL CLASSIFICATION). Any species of animal or
plant declared to be in known danger of extinction throughout all
or a significant part of its range. Protected under Public Law
93-205 as amended.
ENDANGERED SPECIES (STATE CLASSIFICATION). Michigan's list includes
those species on the Federal list that are resident for any part of
their life cycle in Michigan. Also includes indigenous species the
State believes are uncommon and in need of study.
ENDECO. Type 2100 Septic Leachate Detector. See "Septic Snooper".
ENVIRONMENT. The conditions external to a particular object, but
generally limited to those conditions which have a direct and
measurable effect on the object. Usually considered to be the
conditions which surround and influence a particular living
organism, population, or community. The physical environment
includes light, heat, moisture, and other principally abiotic
components. The components of the biotic environment are other
living organisms and tfoeir products.
ENVIRONMENTAL IMPACT STATEMENT. A document required by the National
Environmental Policy Act (PL 91-190, 1969) when a Federal action
would significantly affect the quality of the human environment.
Used in the decision-making process to evaluate the anticipated
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effects (impacts) of the proposed action on the human, biological
and physical environment.
EPILLMINION. The upper layer of generally warm, circulating water in
lakes.
EROSION. The process by which an object is eroded, or worn away, by the
action of wind, water, glacial ice, or combinations of these
agents. Sometimes used to refer to results of chemical actions or
temperature changes. Erosion may be accelerated by human activ-
ities .
EUTROPHIC. Waters with a high concentration of nutrients and hence a
large production of vegetation and frequent die-offs of plants and
animals.
EUTROPHIC LAKES. Shallow lakes, weed-choked at the edges and very rich
in nutrients. The water is characterized by large quantities of
algae, low water transparency, low dissolved oxygen and high BOD.
EUTROPHICATION. The normally slow aging process by which a lake evolves
into a bog or marsh, ultimately assumes a completely terrestrial
state and disappears. During eutrophication the lake becomes so
rich in nutritive compounds, especially nitrogen and phosphorus,
that algae and plant life become superabundant, thereby "choking"
the lake and causing it eventually to dry up. Eutrophication may
be accelerated by human activities. In the process, a once oligo-
trophic lake becomes mesotrophic and then eutrophic.
EVAPOTRANSPIRATION. A process by which water is evaporated and/or
transpired from water, soil, and pl'ant surfaces.
FECAL COLIFORM BACTERIA. See Coliform Bacteria.
FLOE. A sheet of floating ice.
FORCE MAIN. Pipe designed to carry wastewater under pressure.
GLACIAL DEPOSIT. A landform of rock, soil, and earth material deposited
by a melting glacier. Such material was originally picked up by
the glacier and carried along its path; it usually varies in
texture from very fine rock flour to large boulders. Named
according to their location and shape.
GLACIAL DRIFT. Material which has been deposited by a glacier or in
connection with glacial processes. It consists of rock flour,
sand, pebbles, cobbles, and boulders. It may occur in a heter-
ogeneous mass or be more or less well-sorted, according to its
manner of deposition.
GRAVITY SYSTEM. A system of conduits (open or closed) in which no
liquid pumping is required.
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GROUNDWATER. Water that is below the water table.
GROUNDWATER RUNOFF. Groundwater that is discharged iato a stream
channel as spring or seepage water.
HABITAT. The specific place or the general kind of site in which a
plant or animal normally lives during all or part of its life
cycle. An area in which the requirements of a specific plant or
animal are met.
HOLDING TANK. Enclosed tank, usually of fiberglass or concrete, for the
storage of wastewater prior to removal or disposal at another
location.
HYDROPONIC. Refers to growth of plants in a nutrient solution, perhaps
with the mechanical support of an inert medium such as sand.
HYPOLIMNION. Deep, cold and relatively undisturbed water separated from
the surface layer in the lakes of temperate and arctic regions.
IGNEOUS. Rock formed by the solidification of magma (hot molten
material).
INFILTRATION. The flow of a fluid into a substance through pores or
small openings. Commonly used in hydrology to denote the flow of
water into soil material.
INFILTRATION/INFLOW. Total quantity of water entering a sewer system.
Infiltration means entry through such sources as defective pipes,
pipe joints, connections, or manhole walls. Inflow signifies dis-
charge into the sewer system through service connections from such
sources as area or foundation drainage, springs and swamps, storm
waters, street wash waters, or sewers.
INNOVATIVE TECHNOLOGIES. Technologies whose use has not been widely
documented by experience. They may not be variants of conventional
biological or physical/chemical treatment but offer promise as
methods for conservation of energy or wastewater constituents, or
contribute to the elimination of discharge of pollutants.
INTERCEPTOR SEWERS. Sewers used to collect the flows from main and
trunk sewers and carry them to a central point for treatment and
discharge. In a combined sewer system, where street runoff from
rains is allowed to enter the system along with the sewage,
interceptor sewers allow some of the sewage to flow untreated
directly into the receiving stream to prevent the treatment plant
from being overloaded.
LAGOON. In wastewater treatment, a shallow pond, usually man-made, in
which sunlight, algal and bacterial action and oxygen interact to
restore the wastewater to a reasonable state of purity.
LAND TREATMENT. A method of treatment in which soil, air, vegetation,
bacteria, and/or fungi are employed to remove pollutants from
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wastewater. In its simplest form, the method includes three steps:
(1) pretreatment to screen out large solids; (2) secondary treat-
ment and chlorination; and (3) application to cropland, pasture, or
natural vegetation to allow plants and soil microorganisms to
remove additional pollutants. Some of the applied wastewater
evaporates, and the remainder may be allowed to percolate to the
water table, discharged through drain tiles, or reclaimed by wells.
LEACHATE. Solution formed when water percolates through solid wastes,
soil or other materials and extracts soluble or suspendable sub-
stances from the material.
LIMITING FACTOR. A factor whose absence, or excessive concentration,
exerts some restraining influence upon a population of plants,
animals or humans.
LOAM. The textural class name for soil having a moderate amount of
sand, silt, and clay. Loam soils contain 7 to 27% of clay, 28 to
50% of silt, and less than 52% of sand.
LOESS. Soil of wind-blown origin, predominantly silt and fine sand.
MACROPHYTE. A large (not microscopic) plant, usually in an aquatic
habitat.
MELT WATER. Water which is formed from the melting of snow, rime, or
ice.
MESOTROPHIC. Waters with a moderate supply of nutrients and, compared
to eutrophic waters, having less production of organic matter.
MESOTROPHIC LAKE. Lakes of characteristics intermediate between oligo-
trophic and eutrophic, with a moderate supply of nutrients and
plant life.
METHEMOGLOBINEMIA. The presence of methemoglobin in the blood. Methe-
moglobin is the oxidized form of hemoglobin and it is unable to
combine reversibly with oxygen.
MICROSTRAINER. A device for screening suspended solids that are not
removed by sedimentation.
MILLIGRAM PER LITER (mg/1). A concentration of 1/1000 gram of a sub-
stance in 1 liter of water. Because 1 liter of pure water weighs
1,000 grams, the concentration also can be stated as 1 ppm (part
per million, by weight). Used to measure and report the concen-
trations of most substances that commonly occur in natural and
polluted waters.
MORPHOLOGICAL. Pertaining to Morphology.
MORPHOLOGY. The form or structure of a plant or animal, or of a feature
of the earth, such as a stream, a lake, or the land in general.
Also, the science that is concerned with the study of form and
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structure of living organisms. Geomorphology deals with the form
and structure of the earth.
NON-POINT SOURCE. A general source of pollution. Surface water runoff
is an example as it does not originate from a single source and is
not easily controlled.
NUTRIENT BUDGET. The amount of nutrients entering and leaving a body of
water on an annual basis.
NUTRIENTS. Elements or compounds essential as raw materials for the
growth and development of organisms, especially carbon, oxygen,
nitrogen and phosphorus.
OLIGOTROPHIC. Surface waters with good water quality, relatively low
concentrations of nutrients, and modest production of vegetation.
OLIGOTROPHIC LAKES. Lakes with highly transparent water of good
quality, high DO levels, and modest production of aquatic vegeta-
tion.
ORDINANCE. A municipal or county regulation.
OUTWASH. Drift carried by melt water from a glacier and deposited
beyond the marginal moraine.
OUTWASH PLAIN. A plain formed by material deposited by melt water from
a glacier flowing over a more or less flat surface of large area.
Deposits of this origin are usually distinguishable from ordinary
river deposits by the fact that they often grade into moraines and
their constituents bear evidence of glacial origin. Also called
frontal apron.
PARAMETER. Any of a set of physical properties whose values determine
characteristics or behavior.
PERCOLATION. The downward movement of water through pore spaces or
larger voids in soil or rock.
PERMEABILITY. The property or capacity of porous rock, sediment, or soil
to transmit a fluid, usually water, or air; it is a measure of the
relative ease of flow under unequal pressures. Terms used to
describe the permeability of soil are: slow, less than 0.2 inch
per hour; moderately slow, 0.2 to 0.63 inch; moderate, 0.63 to 2.0
inches; moderately rapid. 2.0 to 6.3 inches; and rapid, more than
6.3 inches per hour. A very slow class and a very rapid class also
may be recognized.
PETROGLYPH. An ancient or prehistoric carving or inscription on a rock.
PHOSPHORUS LIMITED. Of all the primary nutrients necessary to support
algal growth, phosphorus is in the shortest supply. Phosphorus can
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limit additional algal growth, or if abundant, can stimulate growth.
of algae.
PHYTOPLANKTON. Floating plants, microsopic in size, that supply small
animals with food and give polluted water its green color and bad
taste.
POINT SOURCE. A stationary source of a large individual emission. This
is a general definition; point source is legally and precisely
defined in Federal regulations.
POVERTY LEVEL. An index providing a range of poverty income cutoffs
adjusted by such factors as family size, sex of family head, number
of children under 18 years of age, and farm or non-farm residence.
PREHISTORIC. A term which describes the period of human development
that occurred before the advent of written records. More
generally, any period in geologic time before written history.
PRESENT WORTH. The sum of money that must be set aside at the beginning
of the planning period in order to amortize the costs of a project
over the planning period.
PRESSURE SEWER SYSTEM. A wastewater collection system in which house-
hold wastes are collected in the building drain and conveyed
therein to the pretreatment and/or pressurization facility. The
system consists of two major elements, the on-site or pressuri-
zation facility, and the primary conductor pressurized sewer main.
PRIMARY PRODUCTION. Growth of green plants resulting from solar energy
being fixed as sugar during photosynthesis.
PRIMARY TREATMENT. The first stage in wastewater treatment in which
nearly all floating or settleable solids are mechanically removed
by screening and sedimentation.
RAPID INFILTRATION. A form of land treatment where wastewater is placed
into spreading basins and applied to the land to percolate into the
soil.
RAPID INFILTRATION BASIN. Unlined wastewater lagoons designed so that
all or part of the wastewater percolates into the underlying soil.
RARE SPECIES. A species not Endangered or Threatened but uncommon and
deserving of further study and monitoring. Peripheral species, not
listed as threatened, may be included in this category along with
those species that were once "threatened" or "endangered" but now
have increasing or protected, stable populations. Used as official
classification by some states.
RECHARGE. The process by which water is added to an aquifer. Used also
to indicate the water that is added. Natural recharge occurs when
water from rainfall or a stream enters the ground and percolates to
the water table. Artificial recharge by spreading water on absorp-
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tive ground over an aquifer or by injecting water through wells is
used to store water and to protect groundwater against the intru-
sion of sea water.
RETENTION TIME. See Detention Time.
ROTATING BIOLOGICAL CONTACTOR (RBC). A device, consisting of plastic
disks that rotate alternately through wastewater and air, used for
secondary treatment of wastewater.
ROUGH FISH. Those fish species considered to be of low sport value when
taken on tackle, or of poor eating quality; e.g. gar, suckers.
Rough fish are more tolerant of widely changing environmental
conditions than are game fish. Also called coarse fish.
RUNOFF. Surface runoff is the water from rainfall, melted snow or
irrigation water that flows over the surface of the land. Ground-
water runoff, or seepage flow from groundwater, is the water that
enters the ground and reappears as surface water. Hydraulic runoff
is groundwater runoff plus the surface runoff that flows to stream
channels, and represents that part of the precipitation on a drainage
basin that is discharged from the basin as streamflow. Runoff can
pick up pollutants from the air or the land and carry them to the
receiving waters.
SANITARY SEWERS. Sewers that transport only domestic or commercial
sewage. Storm water runoff is carried in a separate system. See
sewer.
SANITARY SURVEY. (1) A study of conditions related to the collection,
treatment, and disposal of liquid, solid, or airborne wastes to
determine the potential hazards contributed from these sources to
the environment. (2) A study of the effect of wastewater dis-
charges on sources of water supply, on bathing or other recrea-
tional waters, on shellfish culture, and other related environ-
ments .
SCENIC EASEMENT. A partial transfer of land rights to preserve the
aesthetic attractiveness of the land by restricting activities such
as the removal of trees, placement of billboards, or development
incompatible with the scenic qualities of the land. Just compensa-
tion is given to owners for rights lost. The right of legal tres-
pass is generally not included as part of this easement.
SECCHI DISK. A round plate, 30 cm (1 foot) in diameter, that is used to
measure the transparency of water. The disk is lowered into the
water until it no longer can be seen from the surface. The depth
at which the disk becomes invisible is a measure of transparency.
SECONDARY TREATMENT. The second stage in the treatment of ..-astewater in
which bacteria are utilized to decompose the organic matter in
sewage. This step is accomplished by using such processes as a
trickling filter or activated slugde. Effective secondary treat-
ment processes remove virtually all floating solids and settleable
solids as well as 90% of BOD and suspended solids. Disinfection of
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the effluent by chlorination customarily is the last step in this
process.
SEPTIC SNOOPER. Trademark for the ENDECO (Environmental Devices Corpor-
ation) Type 2100 Septic Leachate Detector. This instrument con-
sists of an underwater probe, a water intake system, an analyzer
control unit and a graphic recorder. Water drawn through the
instrument is continuously analyzed for specific fluorescence and
conductivity. When calibrated against typical effluents, the
instrument can detect and profile effluent-like substances and
thereby locate septic tank leachate or other sources of domestic
sewage entering lakes and streams.
SEPTIC TANK, An underground tank used for the collection of domestic
wastes. Bacteria in the wastes decompose the organic matter, and
the sludge settles to the bottom. The effluent flows through
drains into the ground. Sludge is pumped out at regular intervals.
SEPTIC TANK EFFLUENT PUMP (STEP). Pump designed to transfer settled
wastewater from a septic tank to a sewer.
SEPTIC TANK SOIL ABSORPTION SYSTEM (ST/SAS). A system of wastewater
disposal in which large solids are retained in a tank; fine solids
and liquids are dispersed into the surrounding soil by a system of
pipes.
SEWER, COMBINED. A sewer, or system of sewers, that collects and con-
ducts both sanitary sewage and storm-water runoff. During rainless
periods, most or all of the flow in a combined sewer is composed of
sanitary sewage. During a storm, runoff increases the rate of flow
and may overload the sewage treatment plant to which the sewer
connects. At such times, it is common to divert some of the flow,
without treatment, into the receiving water.
SEWER, INTERCEPTOR. See Interceptor Sewer.
SEWER, LATERAL. A sewer designed and installed to collect sewage from a
limited number of individual properties and conduct it to a trunk
sewer. Also known as a street sewer or collecting sewer.
SEWER, SANITARY. See Sanitary Sewer.
SEWER, STORM. A conduit that collects and transports storm-water run-
off. In many sewerage systems, storm sewers are separate from
those carrying sanitary or industrial wastewater.
SEWER, TRUNK. A sewer designed and installed to collect sewage from a
number of lateral sewers and conduct it to an interceptor sewer or,
in some cases, to a sewage treatment plant.
SHOALING. The bottom effect that influences the height of waves moving
from deep to shallow water.
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SINKING FUND. A fund established by periodic installments to provide
for the retirement of the principal of term bonds.
SLOPE. The incline of the surface of the land. It is usually expressed
as a percent (%) of slope that equals the number of feet of fall
per 100 feet in horizontal distance.
SOIL ASSOCIATION. General term used to describe a pattern of occurrence
of soil types in a geographic area.
SOIL TEXTURAL CLASS. The classification of soil material according to
the proportions of sand, silt, and clay. The principal textural
classes in soil, in increasing order of the amount of silt and
clay, are as follows: sand, loamy sand, sandy loam, loam, silt
loam, sandy clay loam, clay loam, silty clay loam, sandy clay,
silty clay, and clay. These class names are modified to indicate
the size of the sand fraction or the presence of gravel, sandy
loam, gravelly loam, stony clay, and cobbly loam, and are used on
detailed soil maps. These terms apply only to individual soil
horizons or to the surface layer of a soil type.
STATE EQUALIZED VALUATION (SEV). A measure employed within a State to
adjust assessed valuation upward to approximate true market value.
In this way it is possible to relate debt burden to the full value
of taxable property in each community within that State.
STRATIFICATION. The condition of a lake, ocean, or other body of water
when the water column is divided into a relatively cold bottom
layer and a relatively warm surface layer, with a thin boundary
layer (thermocline) between them. Stratification generally occurs
during the summer and during periods of ice cover in the winter.
Overturns, or periods of mixing, occur in the spring and autumn.
Stratification is most common in middle latitudes and is related to
weather conditions, basin morphology, and altitude.
STUB FEE. See Connection Fee.
SUBSTRATE. (1) The surface on which organisms may live; generally the
soil, the bottom of the ocean, of a lake, a stream, or other body
of water, or the face of a rock, piling, or other natural or man-
made structure. (2) The substances used by organisms in liquid
suspension. (3) The liquor in which activated sludge or other
matter is kept in suspension.
SUCCESSION. A gradual sequence of changes or phases in vegetation (or
animals) over a period of time, even if the climate remains un-
altered; hence plant succession. This will proceed until some
situation of equilibrium is attained, and a climax community is
established.
SUPPLEMENTAL USAGE. Those functions that small waste flow districts are
not required to perform in order to comply with EPA Construction
Grants regulations governing individual, on-site wastewater sys-
tems. These functions may, however, be necessary to achieve
administrative or environmental objectives.
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SUSPENDED SOLIDS (SS). Uadissolved particles that are suspended in
water, wastewater or other Liquid, and that contribute to tur-
bidity. The examination of suspended solids plus the BOD test
constitute the two main determinations for water quality performed
at wastewater treatment facilities.
TERTIARY TREATMENT. See Advanced Waste Treatment.
THREATENED SPECIES (FEDERAL CLASSIFICATION). Any species of animal or
plant that is likely to become an Endangered species within the
foreseeable future throughout all or a significant part of its
range. Protected under Public Law 93-205, as amended.
TILL. Deposits of glacial drift laid down in place as the glacier
melts. These deposits are neither sorted nor stratified and con-
sist of a heterogeneous mass of rock flow, sand, pebbles, cobbles,
and boulders.
TOPOGRAPHY. The configuration of a surface area including its relief,
or relative evaluations, and the position of its natural and man-
made features.
TRICKLING FILTER PROCESS. A method of secondary wastewater treatment in
which biological growth is attached to a fixed medium, such as a
bed of rocks, over which wastewater is sprayed. The filter organ-
isms biochemically oxidize the complex organic matter in the waste-
water to simpler materials and energy.
TROPHIC LEVEL. Any of the feeding levels through which the passage of
energy through an ecosystem proceeds. In simplest form, trophic
levels are: primary producers (green plants) herbivores, omni-
vores, predators, scavengers, and decomposers.
TURBIDITY. (1) A condition in water or wastewater caused by the pres-
ence of suspended matter, resulting in the scattering and absorp-
tion of light rays. (2) A measure of fine suspended matter in
liquids. (3) An analytical quantity usually reported in arbitrary
turbidity units determined by measurements of light diffraction.
WATER QUALITY. The relative condition of a body of water as judged by a
comparison between contemporary values and certain more or less
objective standard values for biological, chemical, and/or physical
parameters. The standard values usually are based on a specific
series of intended uses, and may vary as the intended uses vary.
WATER TABLE. The upper level of groundwater that is not confined by an
upper impermeable layer and is under atmospheric pressure. The
upper surface of the substrate that is wholly saturated with ground-
water. This level varies seasonally with the amount of percola-
tion. Where it intersects the ground surface, springs, seepages,
marshes or lakes may occur. Also known as the groundwater level.
WATERSHED. The land area drained by a stream, or by an entire river
system.
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WELL LOG. A chronological record of the soil and rock formations en-
countered in the operation of sinking a well, with either their
thickness or the elevation of the top and bottom of each formation
given. It also usually includes statements about the lithologic
composition and water-bearing characteristics of each formation,
static and pumping water levels, and well yield.
ZONING. The regulation by governmental action (invested by the State to
cities, townships, or counties) of the use of the land, the height
of buildings, and/or the proportion of the land surface that can be
covered by structures.
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BIBLIOGRAPHY
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BIBLIOGRAPHY
Arneman, H. F. 1969. Soils of Minnesota. University of Minnesota.
Department of Soil Science.
Arthur Beard Engineers, Inc. 1978. Seven Lakes Project. EPA-Contract
No. 68-01-4612. Otter Tail Lake, Minnesota.
Bailey, J. R. , R. J. Benoit, J. L. Doclson, J. M. Robb, and H. Wallman.
1969. Study of flow reduction and treatment of wastewater from
households. Cincinnati, OH. US Government Printing Office (GPO).
Cohen, S., and H. Wallman. 1974. Demonstration of waste flow reduction
from households. Environmental Protection Agency, National Envi-
ronmental Research Center, Cincinnati, OH.
Cooper, I. A., and J. W. Rezek. 1977. Septage treatment and disposal.
For EPA, Technology Transfer.
Council on Environmental Quality. 1973. Preparation of environmental
impact statements: Guidelines. 1 August 1973.
Dearth, K. H. 1979. Current costs of conventional approaches. Pre-
sented at EPA National Conference on Less Costly Wastewater Treat-
ment Systems for Small Communities. 12-14 April 1977. Reston, VA.
Environmental Protection Agency, Environmental Photographic Interpreta-
tion Center. 1978.
EPA. January 1978a. Construction costs for municipal wastewater treat-
ment plants, 1973-1977. MCD 37.
EPA. May 1978b. Analysis of O&M costs for municipal wastewater treat-
ment systems. MCD 39.
EPA. May 1978c. Construction cost for municipal conveyance syste,s
1973-1977. MCD 38.
EPA. 1977. National interim primary drinking water regulations of the
Safe Drinking Water Act. 40 CRF 141.
EPA. October 1977. Process design manual for land treatment for land
treatment of minicipal wastewater. EPA 625/1-77-008.
EPA. June 1976. Small community wastewater treatment facilities.
EPA. June 1975. Cost of wastewater treatment by land application.
EPA. July 1974. Manual for preparation of environmental impact state-
ments for wastewater treatment works, facilities plans, and 208
areawide waste treatment management plants.
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Federal Water Pollution Control Act Amendments of 1972, Public Law
9-500.
Fergus Falls Daily Journal. 28 February 1979.
Fergus Falls Health Department. 1969-1976. Bacterial Data from Otter
Tail Lake Outlet.
Gates, Larry F. , and Howard F. Krosch. 1975- Water quality monitoring
program on representative fish lakes, 1974. Special Publication
No. 111. Minnesota Dept. of Natural Resources, Division of Fish
and Wildlife.
Jones, R. A. and G. F. Lee. 1977. Septic Tank disposal systems as
phosphorus sources for surface waters. EPA-600/3-77-129. Robert
S. Kerr Environmental Research Laboratory.
Hickok-RCM International. 1974. Load allocation study for the
Minnesota Pollution Control Agency: Otter Tail River segment.
Wayzata MN.
Kerfoot, W. 1978. Investigation of septic leachate discharges into
Otter Tail Lake, Deer Lake, Lake Blanche, Walker Lake, and Round
Lake. K-V Associates, Inc., Falmouth, MA.
Krohn, Larry. 1977. Land and Resource Management County of Otter Tail.
Fergus Falls Minnesota.
McLaughlin, E. R. 1968. A recycle system for conservation of water in
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