United States
Environmental Protection
Agency
Region VIII
1860 Lincoln St
Denver, Colorado 80295
EPA 908/5-80-002 B
April 1981
^EPA Environmental Final
Impact Statement
Spearfish
Sewerage Needs
Lawrence County near Spearfish, S.D.
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EPA - 908/5-80-002B
FINAL ENVIRONMENTAL IMPACT STATEMENT
SPEARFISH SEWERAGE NEEDS
Lawrence County near Spearfish, South Dakota
Prepared by
U.S. Environmental Protection Agency
Region VIII
1860 Lincoln Street
Denver, Colorado 80295
Approved
Administrator
Date:
APn 1 0 15$ 7
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ACKNOWLEDGEMENTS
Because of the magnitude of the effort required to produce this
environmental impact statement, it is an impossible task to acknowledge
all of the people and agencies who contributed to the final product.
A heart-felt thanks is extended to the individuals who have contributed
and assisted in the completion of this monumental effort. A special-
thanks is offered to all of the secretaries without whose patience and
long hours the project could not have been competed.
DISCLAIMER
This report has been reviewed by the EPA, Region VIII, Water
Division and approved for publication. Mention of trade names
or commercial products does not constitute endorsement or recommendation
for use.
DOCUMENT AVAILABILITY
This document is available in limited quantities through the
U. S. Environmental Protection Agency, Environmental Evaluation
Branch, 1860 Lincoln St., Denver, Colorado 80295. This document
is also available to the public through the National Technical
Information Service, Springfield, Virginia 22161.
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SUMMARY SHEET
'FINAL ENVIRONMENTAL IMPACT STATEMENT
SPEARFISH SEWERAGE NEEDS
LAWRENCE COUNTY NEAR SPEARFISH, SOUTH DAKOTA
Prepared by the U.S. Environmental Protection Agency, Rocky Mountain Prairie
Region, Region VIII, Denver, Colorado, with assistance from Engineering-
Science, Inc., Denver, Colorado
A. Type of Action: ( ) Draft EIS
(X) Final EIS
B. Brief Description of the Proposal
The Region VIII Administrator of tne U.S. Environmental Protection
Agency (EPA) intends to approve Federal matching funds for construction
grant eligible wastewater treatment facilities for unincorporated areas
around Spear fish, South Dakota. The funds will be provided through Title II
of the Federal Water Pollution Control Act Amendments of 1972 (PL 92-500),
as amended in the Clean Water Act of 1977 (PL 95-217). Eligibility
requirements and procedures necessary to qualify for a grant are set forth
in 40 CFR, Part 35, Construction Grants for Wastewater Treatment Works. The
Federal share shall be 75 percent of the total cost found to be eligible.
The purpose of this environmental impact statement is to present an
evaluation of the environmental consequences associated with various
alternatives for wastewater management in areas outlying the City of
Spear fish. The primary issues include: the feasibility or continued use of
on-site wastewater disposal methods, nonpoint source controls, floodplains,
and development.
In July 1978, a Wastewater Facilities Plan for Spearfish, South Dakota
was submitted to EPA and the South Dakota Department of Environmental
Protection for approval. The plan requested Federal funding assistance for
the construction of over 10 miles of interceptors to collect and convey
wastewater from the outlying areas of Spearfish. Tne plan left unanswered
critical questions concerning the effects the interceptors would have on
development in the area. EPA decided to prepare this environmental impact
statement in order to re-evaluate the original facilities plan alternatives
and concurrently has requested the City of Spearfish to update the
facilities plan to include amended alternatives analysis presented in this
impact statement.
C. Lead Agency, Project Officer Contact and Address
The U.S Environmental Protection Agency is the lead agency in a
joint effort with the State of South Dakota and the City of Spearfish,
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South Dakota, to approve plans, necessary permits, and finance or award
grants in order to implement this proposal. Mr. Weston Wilson, U.S.
Environmental Protection Agency, Region VIII is the designated project
o fficer.
Requests for free copies of this document should be addressed to:
Mr. Weston W. Wilson, Project Officer
U.S. Environmental Protection Agency
Region VIII
1860 Lincoln Street
Denver, Colorado 80295
or call (303) 837-4831.
D. Abstract of the Proposed Action
Surface and groundwater pollution problems have been identified in
Spear fish Creek, Higgins Gulch, Christensen Drive, and the Belle Fourche
infiltration gallery. Surface water quality problems have been demonstrated
to be associated with nonpoint source pollution; while groundwater pollution
in Christensen Drive and at the Belle Fourche infiltration gallery have been
influenced by septic tank systems located in the alluvial bottoms of streams
and by nonpoint sources.
In order to correct the water quality problems of the area it is
recommended that nonpoint source control strategies be implemented and two
new interceptor sewer3 be constructed: 1) a 5300 foot, 8 inch gravity
sewer line up Christensen Drive, and 2) a 4000 foot, 8 inch sewer line with
a 2050 foot force main to the West Subdivision in the lower Spearfish
Valley. Based on local and state requirements, these interceptor sewer
lines can only be funded if these unincorporated areas are incorporated into
the City of Spearfish or into the Spearfish Valley Sanitation District. The
West Subdivision has now been annexed into the Spearfish Valley Sanitation
District. The City of Spearfish has yet to take action to annex the Christenser
Drive area. The estimated capital cost of the Christensen Drive interceptor
is $89,398 and the West interceptor is $109,870.
Public health hazards were also identified with two failing septic
tank systems and 12 suspected seasonal failures. The two failing systems
are to be corrected under the direction of the Northern Hills Sanitarian and
the suspected seasonal failures will be monitored. Should failures occur,
corrective action is to be taken.
E. Date filed with EPA and listed in the Federal Register: J\pft j q jggj
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DISTRIBUTION LIST
Farmers Home Administration
U.S. Forest Service
U.S. Department of Interior
National Park Service
Advisory Council on Historic Preservation
U.S. Fish and Wildlife Service
U.S. Heritage Conservation and Recreation Service
U.S. Department of Housing and Urban Development
U.S. Department of Energy
U.S. Department of Health and Human Services
U.S. Department of Agriculture
U.S. Army Corps of Engineers
U.S. Soil Conservation Service
U.S. Geological Survey
U.S. Water and Power Resources Service
U.S. Senate
U.S. House of Representatives
South Dakota Department of Education and Cultural Affairs
South Dakota Department of Wildlife, Parks and Forestry
South Dakota Game and Fish Department
South Dakota Conservation District
South Dakota Geological Society
South Dakota Department of Water and Natural Resources
Black Hills Conservancy District
Meade County
Lawrence County
Butte County
Rapid City
Town of Spearfish
Town of Belle Fourche
Northern Hills Health Department
Black Hills Energy Coalition
South Dakota Stock Growers
South Dakota School of Mines
Black Hills Teachers College
South Dakota Sheep Growers
South Dakota Engineering Society
Butte-Lawrence County Water Quality Association
Trout Unlimited
Homestake Mining Company
Rapid City Journal
Queen City Mail
Scott Engineering
Brady Consultants, Inc.
Woodward Clyde Consultants
Culp/Wessner/Culp, Inc.
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TABLE OF CONTENTS
Page
Chapter 1
Summary and EPA Decision 1
Water Pollution Problems 1
Amended Facility Plan 6
Conclusions 6
EPA Decision 7
Chapter 2
Purpose and Need 11
Chapter 3
Alternatives 17
Introduction 17
Original Alternatives 17
Spearfish Creek Alluvial Valley 18
Upper Higgins Gulch 22
Mountain Plains 22
Christensen Drive 25
No Action 25
Initial Recommendation 25
Alternatives Update 30
Spearfish Creek Alluvial Valley 30
Upgrading Existing Septic Tanks 31
Chapter 4
Affected Environment ; 35
Population and Land Use 35
Spearfish Creek Alluvial Valley 36
Upper Higgins Gulch 37
Mountain Plains 38
Christensen Drive 38
Climate 38
Geology 38
Soils 41
Spearfish Creek Alluvial Valley 42
Weiss-West 42
Upper Higgins Gulch 42
Hardy 42
MacKaben No. 1 43
MacKaben No. 2 43
Deberg-Fuller 44
GrandView Acres 44
Westfield 45
Old Tinton Road 45
Mountain Plains 45
Christensen Drive 46
Vater Quality Criteria and Stream Classification 46
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Page
Water Quality 47
Floodplain 57
Floodplain Management 59
Cultural Resources 60
Chapter 5
Environmental Consequences of the Alternatives 65
Impact Assessment Criteria 65
Costs 65
Reliability ' 65
Flexibility 66
Energy 66
Water Quality 66
Cultural Resources 66
Foreclosure of Future Options 66
Funding 67
System Manageability 67
Alternative Impact Assessment 67
Spearfish Creek Alluvial Valley 67
No Action 67
Holding Tanks 68
Evapotranspiration 68
Gravity Collection/Pressure- Interceptor .... 69
Pressure Effluent System 70
Gravity Collection/Package Plant 70
Upper Higgins Gulch 71
No Action 71
Evapotranspiration 74
Gravity Collection/Interceptor 74
Mountain Plains 75
No Action 75
Evapotranspiration 78
Gravity Collection/Interceptor 78
Christensen Drive 79
No Action 79
Evapotranspiration 82
Gravity Collection/Interceptor 82
Costs 83
Funding 92
Alternative Methods for Financing Alternatives . . .92
General Obligation Bonds 92
Revenue Bonds 92
Special Assessments 92
Bank Loans 93
Contributions 93
Connection Fees 93
Annexation Fees 93
Federal and State Loans and Grants 93
Current Course of Action 96
Financial Options 96
Nonpoint Sources 97
Controlling Nonpoint Sources of Pollution 98
Urban Stormwater Runoff 99
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Agricultural 100
Livestock Confinement/ Concentration Area . . . 100
Dryland/Rangeland 101
Irrigation 104
Construction Management Practices 106
Construction Management Practices 107
Surface Roughening 107
Interception and Diversion Practices 108
Vegetation Stabilization 108
Non-Vegetative Soil Stabilization 108
Vegetative Practices x 108
Structural Control Practices 108
Specialized Sediment Techniques 108
Solid Waste, Construction Chemicals,
Petroleum Products, Other Pollutants . . . .108
Septic Tank Systems 108
Silviculture (Forestry) 108
Mining 110
Nonpoint Source Management Agencies 110
Floodplain/Hazard Identification 112
Introduction H2
Identification of Floodplains 113
Definition 113
Delineation 113
Floodplain Priorities 114
Priority 1 115
Priority 2 115
Priority 3 115
Land Use Controls for Floodplain Development 115
Model Floodplain Ordinance 115
Floodplain Mapping Assistance 116
Chapter 6
Public Participation and Coordination 119
Chapter 7
List of Preparers 123
Chapter 8
References 127
Chapter 9
Index 131
APPENDIX
Appendix A - Comments and Responses A-l
Appendix B - Summary of Water Quality Studies.- B-l
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LIST OF TABLES
No. Title Page
3-1 Cost Summary Interceptor Sewer and Individual
Treatment Alternatives West Development 21
3-2 Cost Summary Interceptor Sewer and Individual
Treatment Alternatives Upper Higgins Gulch 24
3-3 Cost Summary Interceptor Sewer and Individual
Treatment Alternatives Mountain Plains 27
3-4 Cost Summary Interceptor Sewer and Individual
Treatment Alternatives Christensen Drive 29
4-1 1970 Family Income Distribution Spearfish,
South Dakota 36
4-2 Precipitation and Selected Water Quality Data
(June 1978) 51
4-3 Precipitation and Selected Water Quality Data
(July 1978) 52
4-4 Precioitation and Selected Water Quality Data
(August 1978) 53
4-5 Precipitation and Selected Water Quality Data
(September 1978) 54
4-6 Precipitation and Selected Water Quality Data
(October 1978) 55
4-7 Discharge Values for Spearfish Creek 59
5-1 Impact Evaluation Matrix Spearfish Creek
Alluvial Valley 72
5-2 Impact Evaluation Matrix Upper Higgins Gulch 76
5-3 Impact Evaluation Matrix Mountain Plains 80
5-4 Impact Evaluation Matrix Christensen Drive 84
5-5 Failing or Suspected Seasonal Failures of Leach
Fields Throughout the Study Area 86
5-6 Land Treatment Measures and Costs, 1977 Data 103
5-7 Alternative Best Management Practices for
Controlling Construction Erosion 109
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LIST OF TABLES (continued)
No. Tide Page
5-8 Cost Data for Implementation of Soil Erosion
and Sedimentation Control Alternates
(1976 Dollars) 109
LIST OF FIGURES
No. Title Paige
1-1 Regional Area of Interest 2
1-2 EIS Study Area 3
3-1 EIS Study Area 19
3-2 Spearfish Creek Alluvial Valley 20
3-3 Upper Higgins Gulch 23
3-4 Mountain Plains 26
3-5 Christensen Drive 28-
4-1 Generalized Geologic Cross-Section 40
4-2 Water Quality Monitoring Stations 50
4-3 Flood Hazard Boundary Map 58
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SUMMARY AND EPA DECISION
CHAPTER 1
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CHAPTER 1
SUMMARY AND EPA DECISION
The draft Environmental Impact Statement (EIS) issued October 10,
1980, evaluated the environmental consequences of alternative methods of
wastewater disposal in the outlying areas of Spearfish, South Dakota. The
need for wastewater treatment for the City of Spearfish is evaluated in
a separate document. The environmental assessment, which evaluates treat-
ment alternatives for Spearfish, was released April 17, 1980. The EIS
process began in response to documented groundwater and surface water
pollution problems in the outlying areas of Spearfish (see Figure 1-1).
This is the final EIS which responds to comments received on the draft
and specifies EPA's decision. Surface and groundwater pollution was sus-
pected to be originating from septic tank systems. Wastewater was con-
sidered to be:
. The source of sporadic groundwater contamination at and
around the Belle Fourche infiltration gallery.
. The cause of surface water contamination in Higgins Gulch
and Spearfish Creek.
. The cause of groundwater contamination in the Higgins Gulch
area, Mountain Plains area and Christensen Drive area.
A Wastewater Facilities Plan, prepared in 1978, recommended that
nearly ten miles of interceptors be built to sewer outlying areas to
solve these problems because septic tanks were believed unsuitable as a
means of sewage disposal. However, EPA was not sure this was the best
approach given the undesirable growth related environmental effects which
may result. Consequently, an ammended Facility Plan was prepared, supported
by special environmental studies conducted for the draft EIS, which exam-
ined methods of solving water quality and wastewater treatment problems in
greater detail.
WATER POLLUTION PROBLEMS
In order to identify the specific needs a comprehensive understanding
of the extent and causes of the water pollution problems is necessary.
This first step was essential because the specific source of the pollution
was not known. To facilitate this analysis the study area is segregated
by developing areas in the outlying areas of Spearfish (see Figure 1-2).
The City of Belle Fourche has stated that the contamination of their
infiltration gallery has been caused by septic tank effluent entering
surface and groundwater where concentrated development has occurred
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REGIONAL AREA
OF INTEREST
LAWRENCE CO.
BELLE FOURCHE
BUTTE CO.
Redwatsr
; 1~/\
B
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FIGURE 1-2
El S STUDY AREA
Spearf ish
Creek
Alluvial '
Valley J
O'i
Belle Fourche
Infiltration —
Gallery
Developing Areas In
Study Area
Interstate 90
1/4
1/2
miles
Klggins
Gulch
Mountain-
Chnslensen \
Drive I
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(specifically, adjacent to Higgins Gulch). Water sampling at the infil-
tration gallery indicated relatively good quality until the summer of 1977.
In 1977 samples began to show high levels of coliform bacteria, an indi-
cator of disease risk. This condition persisted until 1979. Water sampled
during 1979 and 1980 have not indicated contamination.
During the period of contamination several studies were conducted
around the gallery, in the areas of Higgins Gulch, and Spearfish Creek.
These studies included surface and groundwater monitoring, depth to
groundwater, and aerial imagery and interpretation. The aerial imagery
was utilized to identify and locate individual on-site sewage disposal
systems exhibiting surface failures in areas outside the Spearfish city
limits.
Through aerial imagery interpretation fifty-nine suspected septic
system malfunctions were identified and located. Through field inspection,
suspected failing septic tanks were categorized as follows:
verified failures - two systems,
seasonal failures, during periods of heavy use and/or
moderate to heavy rainfall - twelve systems,
changes in vegetation but no public health hazard -
thirty-three systems
false indications, not associated with septic tanks -
twelve systems (such as artesian wells or roof drains).
Surface and groundwater quality data were evaluated to identify
types, sources of pollution and hydraulic features of Higgins Gulch and
Spearfish Creek as they relate to the infiltration gallery. It was
demonstrated that groundwater at the gallery is recharged by water from
both Higgins Gulch and Spearfish Creek and that groundwater movement
from Higgins Gulch is in a northeasterly direction. This condition is
a result of the groundwater from Higgins Gulch moving through the alluvial
material in its stream bed then entering the Spearfish Creek alluvium.
Sewage disposal by septic tanks and absorption field is practiced
at residential developments which are within a few hundred feet of the
infiltration gallery. Spearfish Creek is in the same alluvial deposits
as the Belle Fourche infiltration gallery. The next closest concentration
of developments using septic systems are in the Higgins Gulch area, about
three miles from the gallery. These developments are located on the
Spearfish Creek bench areas.
Soils in the bench area, according to U.S. Soil Conservation Service
(SCS) are clay-loam and because of their slow permeabilities, not suited
for septic tank absorption fields unless special design features are
incorporated. The tight soil conditions were likely responsible for the
high number of indications of surface failure identified in the aerial
imagery. It has been found that septic tank leach fields located near
the surface function as evapotranspiration systems. This coupled with
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undersized leach fields result in the effluent being taken up by the
cover vegetation and creating a lusher, healthier vegetation than the
surrounding area. Under these circumstances effluent does not appear
to move downward toward the groundwater table.
Because most of the developed area in Higgins Gulch is on these
clay-loam soils, it is concluded that septic tank leach field effluent
is not causing bacterial contamination of the groundwater. Furthermore,
septic systems which are deeper are not suspected of bacterial pollution
of the groundwater because it has been demonstrated that coliform bacteria
are usually filtered by the soil after approximately four feet of vertical
percolation.
With respect to fecal coliform contamination near the Belle Fourche
infiltration gallery, there is no consistent pattern of surface or ground-
water contamination. It has been demonstrated that there is some corre-
lation between rainfall events and groundwater pollution. The analysis
indicates that coliform contamination of the surface waters of Higgins
Gulch and Spearfish Creek below Spearfish is likely caused primarily by
nonpoint discharge sources. Nonpoint discharges are also contributing
to groundwater contamination in the Spearfish Creek-Higgins Gulch alluvium
in the vicinity of the Belle Fourche infiltration gallery where naturally
high groundwater conditions exist. Furthermore, high surface water flows
during storm events increase groundwater elevations in and around the
alluvium of the gallery which cause short-circuiting of septic tank
absorption fields associated with West development on the alluvium, thus
aggrevating coliform contamination of the groundwater.
Additional data have recently (1979) been collected on groundwater
levels in the Spearfish Valley north and west of Spearfish (1). These
data indicate that houses in the upper Higgins Gulch area are not in
violation of septic tank codes relative to groundwater because the ground-
water level is over fifteen feet deep. However, the water table is quite
shallow in the alluvial area around the infiltration gallery and septic
systems in this area could contribute to contamination of the gallery.
Another source of contamination is manure from a livestock confinement
area at the mouth of Higgins Gulch which may be contacting Higgins Gulch
water where it sinks into the alluvium. It should be noted that in 1979
the spring and early summer precipitation was below average. Under average
conditions, the seasonal high water table may be higher than the 1979 data
indicate.
One large septic system serving a campground (Chris1 Campground) lo-
cated along Christensen Drive was found,, using aerial imagery, to fail on
a seasonal basis. During summer months, wastewater loads are excessive,
causing an overloading of the leach field. It appears that the septic
tank/leach field is underdesigned for the number of people using the
system.
An intermittent stream drains the area of Christensen Drive south-
east of the City of Spearfish. Test results indicate abnormal fecal
coliform counts in the stream at a spring. Additional samples taken from
a well at the Miller Ranch (located at the mouth of Christensen Drive)
confirmed groundwater contamination in the drainage area.
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AMENDED FACILITY PLAN
The purpose of the Amended Facility Plan is to develop correctional
measures for identified pollution problems within the Study Area. Cor-
rection measures are necessary to assure adequate control of surface and
groundwater pollution, and protection of public water supplies.
The alternatives evaluated include:
No Federal Action - upgrade verified failing septic tank
systems by individual owners.
Holding tanks.
Evapotranspiration systems.
Sewer interceptors connected to the proposed upgraded
Spearfish wastewater treatment plant.
CONCLUSIONS
Evaluation of data relative to groundwater depth and movement,
ground and surface water quality, rainfall events, soils, geology, and
contamination of the Belle Fourche water supply resulted in EPA con-
cluding:
Surface water pollution in Higgins Gulch and Spearfish
Creek is a consequence of nonpoint source pollution
originating from livestock confinement and pasturing areas,
urban areas, and undeveloped areas.
Sporadic groundwater contamination of the Belle Fourche
infiltration gallery is the result of nonpoint sources
entering Higgins Gulch and Spearfish Creek and septic
tank systems in the area of the West development in the
Spearfish Creek Alluvial Valley.
Septic tank systems in the Upper Higgins Gulch area, on
the Spearfish Creek bench are not contributing to the
sporadic contamination of the Belle Fourche infiltration
gallery.
Surface and groundwater in Christensen Drive has been con-
taminated by septic tank systems in the alluvial valley,
and Chris' Campground.
Septic tank systems are an acceptable means of wastewater
treatment and disposal in the Upper Higgins Gulch area but
are not acceptable in the Spearfish Creek Alluvial Valley
particularly near the Belle Fourche infiltration gallery.
Furthermore, septic tank systems are not desirable for waste-
water treatment where site specific conditions do not conform
to South Dakota regulations. When site specific conditions
are not adequate for conventional septic tank systems
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(Mountain Plains) specially designed systems which overcome
problems may be acceptable.
Water quality and wastewater treatment was not demonstrated
to be a problem in the Mountain Plains area at this time.
However, future problems could develop if wastewater man-
agement is not closely monitored as development occurs. A
worst case analysis by EPA shows that if all lots in Mountain
Plains had failing septic systems, ammonia concentrations in
Spearfish Creek could exceed standards during low stream flows.
A survey of the 12 suspected seasonal failing septic tanks
indicates that leach fields are not adequately designed
according to South Dakota regulations. Two confirmed septic
tank failures have been identified.
EPA DECISION
EPA proposes the following decision:
a) To approve for grant eligibility under the Clean Water Act
75 percent funding for two new sewer interceptors: 1) a 5300 foot
8 inch gravity sewer line up Christensen Drive and 2) a 4000 foot
8 inch sewer line and a 2050 foot force main and pump station to the
West Subdivision in lower Spearfish Valley. Such new sewer interceptors
can only be funded if these unincorporated areas are incorporated into
the City of Spearfish (Christensen Drive) or into the Spearfish Valley
Sanitation District (West Subdivision). The West Subdivision has now
been annexed into the Spearfish Valley Sanitation District while the City
of Spearfish has yet to take action to annex the Christensen Drive area.
The estimated capital cost of the Christensen Drive interceptor is
$89,320 and of the West interceptor is $109,870.
b) EPA requests that the South Dakota Department of Water and Natural
Resources(DWNR), when possible, work closely with the local and county
zoning and health officials in insuring enforcement of the state approved
septic tank codes with respect to new and existing residential con-
struction near the City of Spearfish. The Northern Hills Sanitarian has
ordered conversion of two residences identified as having definite surface
failures. EPA requests that the State Department of Water and Natural Resources
and the Northern Hills Sanitarian continue to monitor the 12 residences
identified as having suspected seasonal failures.
Should surface failures occur that in the opinion of DWNR represent
public health nuisances they should advise the Northern Hills Sanitarian
to take corrective actions. As most homes are on half-acre lots, over
20,000 square feet, it is EPA's opinion that there is sufficient space
for leach field expansion in order to comply with the state codes. This
corrective action should be done at the owner's expense.
c) When the draft EIS was published EPA proposed to restrict grants
to the City of Spearfish and/or the Spearfish Valley Sanitation District
such that no new sewer connections would be allowed within the designated
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100-year floodplain of these two jurisdictions as of the date of the grant
award unless a variance was obtained from EPA.
The proposed grant condition was: "The grantee and local jurisdictions
in the Spearfish Service Area shall not accept a sewerage connection to any
interceptor funded by this grant, from any residential, commercial or in-
dustrial structure receiving a local building permit after the date of this
grant, if the structure is located within a designated 100-year floodplain.
The grantee and local jurisdictions are permitted to accept a sewerage
connection from any residential, commercial or industrial structure located
within a designated 100-year floodplain, if the structure is in existence
or was issued a local building permit prior to the date of award of the
Step 2 grant."
A variance of this condition will be considered by EPA if the grantee,
in conjunction with each local jurisdiction in the Spearfish Service Area
submits site-specific documentation (including detailed maps of specific
plats recommended for variances) that there is no practicable alternative
to development within the 100-year floodplain. A minimum requirement for a
variance to be granted is a demonstration that the procedures outlined in
Floodplain Management Guidelines dated February 10, 1978 have been followed.
If such a variance is granted, the proposed structures must comply with the
floodplain management standards of the National Flood Insurance Program,
and the proposed floodplain development will not alter the 100-year flood-
plain so as to increase the risk of flooding to upstream or downstream
property. Under no circumstances, will a variance be granted for develop-
ment located in the floodway as defined by the National Flood Insurance
Program and identified on HUD Flood Boundary Maps. The grantee should
refer to Federal Executive Order 11988 dated May 24, 1977, pertaining to
Floodplain Management and EPA's Statement of Procedure for Floodplain
Management and Wetlands Protection, dated January 5, 1979 (44 CFR 1455)".
EPA has now changed its policy with respect to this floodplain require-
ment to give local governments more flexibility in developing a local
floodplain management program and to relieve EPA of the administrative
burden of processing individual variances. However, the basic requirement
remains, that is to limit development within the 100-year floodplain unless
there is no practical alternative in order to comply with Federal Executive
Order 11988 on protecting natural floodplains.
The best way to achieve this is for each federal grant recipient to
develop an effective program or ordinance to control development within the
designated 100-year floodplain and administer such ordinances at the local
level. Therefore, EPA now will require the following floodplain grant
condition:
"The grantee, in conjunction with the other local jurisdictions
in the service area for this project, shall provide EPA with
documentation that each local jurisdiction in the service area
has developed an effective program to control development within
the designated 100-year floodplain. At a minimum, an effective
program must comply with the floodplain management standards of
the National Flood Insurance Program, including designation
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and regulation of the floodway. The grantee should refer to Federal
Executive Order 11988 dated May 24, 1977, pertaining to Floodplain
Management and EPA's Statement of Procedure for Floodplain Management
and Wetlands Protection, dated January 5, 1979, (44 CFR 1455)".
This condition must be met prior to award of the Step 3 construction
grant. For the Christensen Drive area (if annexed by the City) the
condition will apply to the City of Spearfish which would be the grantee.
For the West Subdivision area, Lawrence County will have to show compliance
with this floodplain grant condition since only the County administers
land use policy within the single purpose sanitation district.
d) The draft EIS also stated that Spearfish and Lawrence County
should pursue nonpoint source control measures as identified in the Black
Hills 208 plan and the EIS, whereby an adopted and approved erosion and
sediment control ordinance is enacted. EPA will require as a grant
condition that the City of Spearfish and Lawrence County show good faith
efforts to adopt nonpoint source control measures, including an erosion
and sediment control ordinance.
e) Because many of these problems have resulted from improper or
unrestricted development in the Study Area, EPA advises Lawrence County
to:
1) Enforce strict adherence to South Dakota codes on
individual disposal systems especially determination of the
seasonal high groundwater level. EPA recommends that Lawrence
County Board of Supervisors continue to approve properly
designed septic systems in the Higgins Gulch and bench area,
but that they should develop a policy of excluding septic
tank installation from areas within the Spearfish Valley
alluvium that have groundwater within ten (10) feet of the
surface.
2) Implement a floodplain program similar to the one
EPA proposed for the City of Spearfish and the Spearfish Valley
Sanitation District for the entire county whereby all residential
development is restricted within the designated 100-year flood-
plain to the minimal standards defined in the National Flood
Insurance Program.
3) Pursue and develop community acceptable nonpoint
source controls as identified in the Black Hills 208 plan and
this EIS whereby sources of stream pollution such as improper
irrigation practices, excessive concentration of cattle and solid
waste dumping in streams is controlled by the county.
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f) In addition, the City of Belle Fourche is responsible for the
quality of water that it serves to its consumers. Since there is no
longer an opportunity to protect the entire watershed, the city must rely
on protecting as much of the area around the gallery as possible and conduct
vigilant monitoring of water quality. EPA has notified Belle Fourche (by
letter of February 27, 1981) that this system is considered a surface water
source and as such certain additional monitoring will be required. It is
further suggested that Belle Fourche provide additional physical control
of the gallery area by adding fencing improvements. Unfortunately, the
City of Belle Fourche can anticipate a decline in water quality unless
nonpoint sources are controlled upstream and may need to provide further
treatment or find another source of water.
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PURPOSE AND NEED
CHAPTER 2 X
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CHAPTER 2
PURPOSE AND NEED
The existing wastewater treatment facility of the City and the
Sanitation District is a two-stage stabilization pond (lagoon) that was
constructed in 1972. Shortly after the discharge of wastewater into the
ponds, excessive exfiltration occurred and untreated wastewater began
flowing into the Spring Creek drainage (See Figure 1-1). The remaining
areas of the study area use on-site wastewater facilities.
On August 10, 1978, a 201 Wastewater Facilities Plan for Spearfish,
South Dakota was submitted to the South Dakota Department of Environmental
Protection (DEP) and the U.S. Environmental Protection Agency (EPA) for
approval (2). The facilities plan addressed the wastewater treatment and
management needs of the designated 201 study area. In addition to the
City of Spearfish, the study area includes the Spearfish Valley Sanitation
District and four development areas.
• Christensen Drive
' Mountain Plains
• Higgins Gulch
• Weiss-West Developments
These features, as well as other cultural features of the area, are
illustrated on Figure 1-2.
The facilities plan recommended the construction of a new wastewater
treatment plant with a capacity of 0.8 million gallons per day (MGD) to
serve the 1990 estimated population of 10,300 people. The plan also
recommends construction of approximately 10 miles of interceptor sewers
into presently unsewered areas to eliminate suspected groundwater con-
tamination.
The recommendation of the facility plan for extensive sewer interceptors
and a new wastewater treatment facility were developed based on the following
conclusions:
Excessive exfiltration from the stabilization ponds is contaminating
the groundwater and surface water of the Spring Creek drainage and
is a severe threat to health.
The geologic strata within the study area poses a risk of potential
groundwater contamination by wastewaters treated or stored in
stabilization or holding ponds.
13
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Septic tank - leach field individual treatment systems are con-
taminating the groundwaters and potable drinking waters in the
Spearfish Creek and Higgins Gulch alluvial drainages.
Development within the study area is haphazard with no planning
as to location of development in relation to floodplain or with
regards to proper wastewater treatment and disposal.
Infiltration into portions of the sewer collection system is
excessive and requires additional investigation.
A wastewater treatment facility that produces a high quality
effluent must be provided to meet the stream water quality
standards of Spearfish Creek and to maintain the aesthetic and
environmental quality of the Study Area.
Because of the severe pollution and public health hazards associated
with the failing sewage lagoons, work is proceeding with the development
of alternatives for a new plant. This new plant will be sized for an
initial staging period of ten years. A staged approach is selected so
that the immediate needs for wastewater treatment can be met while additi-
onal evaluation is conducted of sewerage needs in unsewered areas. (See
EPA's Final Environmental Assessment dated April 17, 1980, for a description
of the problems of wastewater treatment and site selection for the City
of Spearfish.) The South Dakota Department of Water and Natural Resources and EPA
have prepared a revised environmental assessment which recommends approval
of an oxidation ditch system with filters near the existing lagoons followed
by a discharge to lower Spring Creek.
EPA determined that adverse environmental .impacts, including induced
development in floodplains may result from construction of the recommended
interceptors into outlying areas. The City of Spearfish was required to
re-evaluate alternatives for wastewater management in the outlying areas
to determine the most environmentally sound and cost-effective management
strategy. This action is predicated on the fact that surface and ground-
water in the Study Area has experienced pollution above acceptable limits
and that contamination of the Belle Fourche water supply has resulted as
a consequence of this pollution.
14
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ALTERNATIVES
CHAPTER 3
2>.
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CHAPTER 3
ALTERNATIVES
INTRODUCTION
The City of Spearfish has proceeded with the development of alter-
natives for wastewater treatment to correct problems associated with their
failing lagoons. The City has also retained the engineering firm of
Scott Engineering to reevaluate wastewater management alternatives for the
unsewered area outside the City limits and the Spearfish Valley Sanitation
District. This environmental impact statement is being prepared in con-
junction with the update of the 201 Facility Plan for these outlying areas.
In recent years there has been an increase in septic tank-leach
field systems in outlying areas as a consequence of increased residential
development. Concern has been expressed that these on-site systems are
potentially contaminating groundwater and the Belle Fourche water supply.
ORIGINAL ALTERNATIVES
The original Facilities Plan, prepared by Brady Engineers in 1978,
recommends that developments in outlying areas abandon their on-site
systems and connect to the City's sanitary sewerage system. This
selected action was predicated on the suspicion that these systems were
potentially contaminating groundwater in the area.
Several wastewater treatment alternative systems were considered in
the original Facilities Plan as feasible for development in the outlying
areas. These alternatives include:
interceptor sewers connected to the City system
holding tanks
evapotranspiration systems
Operation and maintenance of the interceptor sewers would be the
responsibility of the City. Holding tanks require pumping on a regular
schedule with primary responsibility with the homeowner. The evapo-
transpiration system would require pumping during the winter when the
rate of evapotranspiration is reduced, to prevent system overflow.
The homeowner would have the primary responsibility for maintenance
of the evaportranspiration system. Pumpage from the holding tanks
and evapotranspiration systems would be treated in the City treatment
plant.
17
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Each of these alternative treatment systems is evaluated in terms
of their applicability to the unsewered outlying developments. These
developments are separated into the following areas:
• Spearfish Creek Alluvial Valley
• Upper Higgins Gulch
• Mountain Plains
' Christensen Drive
These developments are illustrated on Figure 3-1.
Spearfish Creek Alluvial Valley
Two developments are located in the Spearfish Creek Alluvial Valley,
the Hope Weiss Development (Brookview Acres) and the West Subdivision
(Hubbard Development), along with scattered residential and agricultural
developments, (See Figure 3-2).
The Hope Weiss Development, except for one dwelling, is connected
to the City of Spearfish's sewer system via a privately owned transmission
line. This line is preceded by a small package-type wastewater treatment
plant. The remaining developments in the area are on individual disposal
systems.
The original Facility Plan states that the City must allow the West
Subdivision to connect to the existing interceptor sewer. This is to
eliminate the threat to local groundwaters and the Belle Fourche water
supply of being contaminated.
The original Facility Plan identified six trailer homes with a
potential occupancy of 35 homes on the existing lots. Twenty-year
population projection for the development is 105. Design peak flow would
be 16,000 gallons per day (gpd).
Original cost estimates were developed for the three wastewater
treatment alternatives. The interceptor sewer alternative would consist
of an eight-inch interceptor with a lift station and a four-inch pressure
line to the existing 18-inch interceptor from the City of Spearfish. A
summary of the original cost estimates of the alternatives is presented
in Table 3-1.
18
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FIGURE 3-1
El S STUDY AREA
Spearf Ish
Creek
Alluvial '
Valley/
o-;
Belle Fourche
Infiltration —
Gallery
Developing Areas In
Study Area
Interstate 90
1/4
1/2
' Hlgglns
Gulch
19
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1/2
miles
FIGURE 3-2
SPEARFISH CREEK ALLUVIAL VALLEY
Developing Areas
Balls Fourche
' Infiltration Gallery
?
spring
20
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TABLE 3-1
COST SUMMARY
ORIGINAL 1978 INTERCEPTOR SEWER AND INDIVIDUAL TREATMENT ALTERNATIVES
WEST DEVELOPMENT
A1 ternative
Interceptor Sewer
Holding Tank
InJ tlal
Design
Capital
Cost
$117,935
18,000
105,000
Life
Years
AO
20
20
Evapotranspiration System
InLtial 36,000 20
Design 210,000 20
Salvage * Bond
Va]ue Requirements
Total Project
$58,960 $10,810
0
0
0
0
1,650
9,530
3,300
19,250
0 & M
Cost
$ 3,000
11,580
67,550
4,020
23,450
Total Annual
Cost
$13,810
13,230
77,080
7,320
42,700
Monthly Cost
per tap
$ 44.25
183.75
183.75
101.70
101.70
** Interceptor Sewer 30,735 40
Holding Tank
Initial 2,700 20
Design 15,750 20
*** Evapotranspiration System
Initial 5,400 20
Design 31,500 20
Loca] Share
15,370
0
0
0
0
2,820
250
1,440
4 95
2,890
3,000
11,580
67,550
4,020
23,450
5,820
11,830
68,990
4,515
26,340
18.65
164.30
164.30
62. 70
62. 70
* (6-5/8% - 20 years)
** 75% Federal Share
*** 85% Federal Share
SOURCE: Brady Engineers. Wastewater Facilities Plan. Spearfish, South Dakota. 1978
Updated costs from amended facilities plan are shown in Table 5-1.
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Upper Higgins Gulch
Residential developments included in Upper Higgins Gulch consist
of the following subdivisions:
MacKaben No. 1
MacKaben No. 2
DeBerg
Grand View Acres
Deer Meadows
• Westfield
Hardy
Fuller
Old Tinton Road
These developments are shown on Figure 3-3.
Development in these areas has been at a rapid rate in recent years.
All of the residences have on-site sewage disposal systems. The original
Facility Plan states that these systems constitutes a threat to the
quality of groundwater within the drainage area.
Several of the subdivisions have been located within or immediately
adjacent to drainageways. This creates a potential hazard to dwellings
and wastewater treatment systems during high runoff events. The potentially
effected developments include: Deer Meadows No. 1 which is in the Higgins
Gulch drainage, Westfield is located in the Johnston Gulch drainage, and
DeBerg, Fuller, and MacKaben No. 1 are adjacent to drainages.
There are currently 88 homes in the developments in the Higgins
Gulch drainage west of the City of Spearfish. The 20-year projected number
of homes in the drainage is 370. The existing population of the subdivisions
within the Higgins Gulch drainage area is 160 contributing approximately
16,000 gpd to the septic tank systems. A projected 20-year population for
the drainage area is 1,100 people. Twenty-year design peak flow from the
area is 165,000 gpd. It is estimated that an eight-inch interceptor sewer
line would be adequate to convey the future wastewater flows from this area
to the City system.
Original cost estimates of the three wastewater conveyance/treatment
alternatives for Upper Higgins Gulch are summarized in Table 3-2. The
original cost estimates did not include service for Grand View Acres,
Hardy, or Old Tinton Road developments.
Mountain Plains
The Mountain Plains subdivision is adjacent to the southern border of
the City of Spearfish. There are approximately ten homes in the development,
all on individual disposal systems. There are currently 62 lots in the
development. An additional filing on an additional 600 acres consisting
22
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1/4
1/2
miles
Hardy
Subdivision
Hwy 14
MacKaben
No. 1
FIGURE 3-3
UPPER HIGGINS GULCH
Over Meadows
No. 2
Developing
Areas
Westfield
Homestake Rd
Old Tinton Road
•c
23
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TABLE 3-2
COST SUMMARY
ORIGINAL 1978 INTERCEPTOR SEWER AND INDIVIDUAL TREATMENT ALTERNATIVES
UPPER HIGGINS GULCH
Capital
Alternative Cost
Interceptor Sewer $ 494,400
Holding Tanks
Initial 264,000
Design 1,110,000
Evapotranspiration System
Initial 528,000
Design 2,220,000
Life Salvage * Bond O & M
Years Value Requirements Cost
20
20
20
20
Total Project
40 $247,200 $ 45,330
0
0
0
0
24,200
101,780
48,410
203,550
$ 5,000
169,840
714,100
58,960
247,900
Total Annual Monthly Cost
Cost per tap
$ 50,330 $ 18.35
194,040
815,880
107,370
451,450
183.75
183.75
101.70
101.70
** Interceptor Sewer 138,600
*** Holding Tanks
Initial 39,600
Design 166,500
Evapotranspiration System
Initial 79,200
Design 333,000
40
20
20
20
20
Local Share
69,000
0
0
0
0
12,710
3,630
15,270
7,260
30,535
5,000
169,840
714,100
58,960
247,900
17,710
173,470
729,370
66,220
278,435
6.45
164.30
164.30
62.70
62.70
* (6-5/8% - 20 years)
** 75% Federal Share
*** 85% Federal Share
SOURCE: Brady Engineers. Wastewater Facilities Plan. Spearfish, South Dakota. 1978
Updated costs from amended facilities plan are shown in Table 5-2.
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of approximately 119 lots has been made. The subdivision lies on the
Minnekahta Limestone formation. Seepage from individual wastewater
treatment into the underlying groundwater may occur because Minnekahta
Limestone is severely fractured. The subdivision lies above, the Spear-
fish Creek drainage. Effluent from the individual wastewater treatment
facilities within the development could reach the surface water of Spear-
fish Creek by traveling through fractures in the limestone formation.
(See Figure 3-4).
Twenty-year population projection is 280 people. Twenty-year design
peak flow is 42,000 gpd. An eight-inch interceptor would be of adequate
size to service the area for the interceptor sewer alternative.
Original cost estimates for the interceptor and on-site treatement
alternatives are presented in Table 3-3.
Christensen Drive
The Christensen Drive Subdivision is located southeast of the City of
Speavfish. The development consists of 28 residential units and two large
campgrounds. The campgrounds (Chris* and Mountain View)support a summer-
time population of 250 people. Sewage disposal is accomplished by individ-
ual, on-site systems.
Septic tank systems used for wastewater treatment appear to be over-
loaded during the summer months. Contamination of the groundwater within
the drainage area has been documented (2) by test results of water from
a domestic water well at the Miller Ranch. (See Figure 3-5).
Based on a design peak flow of 25,000 gpd during the peak summertime
loads an eight-inch sewer line would handle sewage flow.
Presented in Table 3-4 is a summary of the original cost estimates
for the conveyance/treatment alternatives the facilities plan considered
for Christensen Drive.
No Action
The no action alternative for the outlying areas was summarily dis-
missed in the 1978 facilities plan because of the potential contamination
of groundwater which could create a risk of disease transmission associated
with the use of shallow domestic water wells.
Initial Recommendation
The original facilities plan, after evaluating the economic, environ-
mental, and social implications of a comprehensive wastewater treatment
disposal plan makes the following recommendations for the outlying areas:
25
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FIGURE 3-4
MOUNTAIN PLAINS
Mountain Plain* No,?
Developing
Areas
miles
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TABLE 3-3
COST SUMMARY
ORIGINAL 1978 INTERCEPTOR SEWER AND INDIVIDUAL TREATMENT ALTERNATIVES
MOUNTAIN PLAINS
Alternat ive
Interceptor Sewer
Holding Tanks
Initial
Design
Evapotranspiration System
Initial
Design
** Interceptor Sewer
*** Holding Tanks
Init ial
Design
*** Evapotranspiration System
Initial
Des ign
Capital Life Salvage * Bond 0 & M
Cost Years Value Requirements Cost
$274,820 40
60,000
285,000
120,000
570,000
9,000
42,750
18,000
85,500
20
20
20
20
68,710 40
20
20
20
20
Total Project
$137,410 $25,200
0
0
0
0
Local Share
0
0
0
0
5,500
26,130
11,000
52,260
6,300
830
3,920
1,650
7,840
$ 2,500
38,600
183,350
13,400
63,650
2,500
38,600
183,350
13,400
63,650
Total Annual
Cost
$ 27,700
44.100
209,480
24,400
115,910
8,800
39,430
187,270
15,050
71,490
Monthly Cost
per tap
$ 42.00
183.75
183.75
101.70
101.70
13.35
164.30
164.30
62.70
62.70
* (6-5/8% - 20 years)
** 75% Federal Share
*** 85% Federal Share
SOURCE: Brady Engineers. Wastewater Facilities Plan. Spearfish, South Dakota. 1978
Updated costs from amended facilities plan are shown in Table 5-3.
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FIGURE 3-5
CHRISTENSEN DRIVE
'Chris' Campground
"/Mountain View
. Campground
miles
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TABLE 3-4
COST SUMMARY
ORIGINAL 1978 INTERCEPTOR SEWER AND INDIVIDUAL TREATMENT ALTERNATIVES
CHRISTENSEN DRIVE
Alternat ive
Capital
Cost
Life
Years
Salvage
Value
* Bond
Requirements
0 & M Total Annual
Cost Cost
Monthly Cost
per tap
Interceptor Sewer
$57,220
Total Project
40 $28,600 $ 5,250
$ 1,000 $ 6,250
$ 13.50
Holding Tanks
Initial
Design
81,000
150,000
20
20
0
0
7,430
13,750
52,380
97,000
59,810
110,750
184.60
184.60
EvapotranspiraLion System
Initial 162,000 20
Design 300,000 20
0
0
14,050
27,510
18,230
33,750
33,080
61,260
102.10
102.10
vO
** Interceptor Sewer
*** Holding Tanks
Initial
Design
$ 14,305
12,150
22,500
40
20
on
*** Evapotranspiration System
initial 24,300 20
Design 45,000 20
Local Share
$ 7,150 $ 1,315
0
0
0
0
1,115
2,065
2,230
4,130
$ 1,000
52,380
97,000
18,230
33,750
$ 2,315
53,495
99,065
20,460
37,880
$ 5.10
165.10
165.10
63.15
63.15
* (6-5/8% - 20 yrs.)
**¦ 75% Federal Share
k** 85% Federal Share
SOURCE: Brady Engineers. Wastewater Facilities Plan. Spearfish, South Dakota. 1978.
Updated costs from amended facilities plan are shown in Table 5-4.
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Interceptor sewers be constructed to service all of the major
developments in the outlying areas that are threatening the
quality of the local groundwater by discharges from septic
tank - leach field systems.
No septic tank-leach field treatment systems be allowed within
the Planning Area. Isolated homes that cannot be economically
connected to the sewer collection system must install self-contained
treatment sytems approved by a registered professional engineer.
A Spearfish Sanitation District be established to include the
thirty-one square mile Planning Area. The prime responsibilities
of this governing body would be to manage the existing wastewater
collection and treatment facilities, to establish regulations for
construction of new treatment facilities, to collect sewer use
charges and/or taxes, and enforce the established regulations.
Additional staffing be provided to the offices of the Northern
Hills Sanitarian and Lawrence County Planning and Zoning to
provide more scrutiny in the issuing of building permits and
in the construction of individual wastewater treatment facilities
within the Planning Area.
ALTERNATIVES UPDATE
The original Facilities Plan concludes that septic tank - leach
fields are a source of contamination to groundwaters and potable drinking
waters in the Spearfish Creek and Higgins Gulch alluvial drainage and
that development in the Study Area has been haphazard with no planning
as to location of development in relation to floodplains or with regard
to proper wastewater treatment and disposal.
The update of the Facilities Plan and this EIS focus on wastewater
disposal, potential groundwater and surface water contamination, and
development policies. This analysis is based on the information collected,
analyzed, and presented in the document, Existing Data-Base Evaluation,
Spearfish, South Dakota, which was distributed for review to the Citizens
Advisory Committee, the City of Spearfish, the City of Belle Fourche,
Lawrence County and the South Dakota Department of Water and Natural Resources
in August 1979.
Spearfish Creek Alluvial Valley
Septic tanks in the Spearfish Creek Alluvial Valley are believed to
be a contributor (along with nonpoint sources) to the contamination of the
Belle Fourche water supply. Because of the high groundwater levels and
potential flood hazards associated with this area, the following alter-
natives are identified as suited for wastewater collection and disposal:
_30
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Gravity collection and pressure interceptor line to the City of
Spearfish system.
Pressure effluent collection system from septic tanks connected
to the Hope Weiss treatment plant and pumped to the City's system.
Gravity collection conveyed to the Hope Weiss treatment plant.
Upgrading Existing Septic Tanks
Two failing septic tank systems have been identified through the use
of aerial imagery. One system had no leach field and was discharging
effluent directly to Higgins Gulch. A leach field in conformance with
South Dakota regulations has recently been installed for this system. The
second system is exhibiting surfacing of effluent. Available information
on the system indicates the leach field is undersized for a two bedroom
home and local soil conditions. It is estimated that an additional 250
square feet (80 linear feet) of leach field is required. Assuming an
average cost of $6 a linear foot for leach field piping, the upgrading
costs will be about $480.
Twelve septic tank systems have been identified as suspected of being
seasonal failures. During periods of heavy rainfall saturation of heavy
clay soils in the bench area of Upper Higgins Gulch may cause septic tank
effluent surfacing. The 12 suspected failures are located throughout the
Study Area, all on impermeable clay soils. It is recommended that these
systems be monitored during spring and summer rainfall periods by the
Northern Hills Sanitarian to verify any failures. Those systems not
failing are functioning as evapotranspiration systems. Those systems
found to be failing are to be upgraded under the direction of the Northern
Hills Sanitarian or by the Department of Water and Natural Resources to
eliminate the health hazards associated with surfacing effluent.
A survey conducted by Scott Engineers showed that all 12 of the
leach fields of the suspected failing systems are underdesigned. In
the event that all 12 systems are verified as failing it is possible that
complete replacement of the leach fields will be required at the owner's
expense.
There were an additional 45 septic tank systems identified using
aerial imagery as suspected failures. Field inspection of these systems
concluded that thirty-three are functioning as evapotranspiration systems
and not creating a public health hazard and 12 are false indications,
not associated with the on-site disposal systems (artesian wells or roof
drains.)
31
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AFFECTED ENVIRONMENT
CHAPTER 4
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CHAPTER 4
AFFECTED ENVIRONMENT
Spearfish, South Dakota is located on the northern edge of the Black
Hills in Lawrence County. The proximity to the Black Hills and the Spear-
fish Creek Valley offers a year round focal point for recreational
activities. Along with the recreational opportunities Spearfish is an
area which is experiencing energy related growth. These two features
of the area will continue to contribute to the growth and development
of the area.
The Study Area is approximately 31 square miles and includes the
City of Spearfish and the surrounding environs. The Study Area has been
divided into the following subareas.
Spearfish Creek Alluvial Valley
Upper Higgins Gulch
Mountain Plains
Christensen Drive
These four areas represent the outlying areas and exclude the City
of Spearfish and the Spearfish Valley Sanitation District.
POPULATION AND LAND USE
The 1977 population estimate for the outlying area is estimated to
be 700 people (2) and the 1998 projection is 3,230. According to the
Lawrence County Planning and Zoning Administrator (3) there will be
approximately 2950 homesites needed by 1998 for the entire Study Area.
The housing market in the Study Area is expected to be oriented toward
small acreages and not land efficient development. This type of develop-
ment in outlying areas will tend to encourage the use of on-site waste-
water treatment systems.
Assuming that a 1970 family income of $10,000 or more is considered
in the upper income group, 30 percent of the families in Spearfish would
have an upper level income (See Table 4-1). Projecting this percentage
to future populations there is expected to be about 880 upper level in-
come families in the area or 880 upper level income homesites required.
Virtually all of the homesites available in the outlying areas are
large lots which will require upper level income earnings to finance the
land and home construction.
35
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TABLE 4-1
1970 FAMILY INCOME DISTRIBUTION
SPEARFISH, SOUTH DAKOTA
Income, $ Families Percent of Total
Less than 3,000
119
12.0
3,000 to 4,999
159
16.0
5,000 to 6,999
163
16.4
7,000 to 9,999
247
24.9
10,000 to 14,999
191
19.3
15,000 to 24,999
105
10.6
25,000 or more
8
0.8
There are currently between 300 and 350 available homesites in the
outlying areas, excluding the Spearfish Valley Sanitation District. These
homesites are roughly distributed as follows:
Spearfish Creek Alluvial Valley 30 sites
Upper Higgins Gulch 110 sites
Mountain Plains 160 sites
Christensen Drive 40 sites
It is expected that these available homesites will be developed
during the next twenty years. Based on the assumed need for 880 home-
sites there will be a shortage of about 540 homesites.
At this time it is not possible to project the distribution of
these additional 540 homesites in the outlying areas.
The dominate land use of the outlying area is agricultural (grazing).
Land use has been identified by the South Dakota State Planning Bureau
in cooperation with the Sixth District Council of Governments. (5)
The Spearfish Creek Alluvial Valley
There are two developments in the Spearfish Creek Alluvial Valley,
the West development and Hope Weiss development, with some scattered
development. The West-Weiss development consists of single family dwellings.
36
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With the exception of one dwelling, the Hope Weiss development is
connected to the City of Spearfish's sewer system via a privately owned sewer
line which is preceded by a small wastewater treatment plant. The remaining
developments in the area are on individual sewage disposal systems.
Upper Hjogins Gulch
Residential development in this area consists of the following sub-
divisions :
MacKaben No. 1
MacKaben No. 2
DeBerg
Grand View Acres
Deer Meadows
Westfield
Hardy
• Fuller
Old Tinton Road
MacKaben No. 1 and MacKaben No. 2 have 25 and 12 residences, respectively.
In the Deberg and Fuller developments there are about 20 homes. Grand View
Acres currently has 12 homes, Deer Meadows has 15 to 20 homes, and Westfield
has about 15 homes. All of these residences have on-site sewage disposal
systems.
Not all of the lots in Upper Higgins Gulch have been developed, thus
maximum density has not yet occurred. It is anticipated that this area
will continue to develop as demonstrated by a recent filing of an additional
80 acres for Deer Meadows No. 2.
In the Deberg development platted lots range in size from 1.92 acres
to 0.51 acre. Four of the lots are 0.78 acre, two are 0.51 acre, ana one
is 0.63 acre. In the Fuller addition, 12 plotted lots range in size from
2.57 acres to 0.61 acre. Of these lots, four are 0.61 acre, four are 0.62
acre, and three are 0.95, 0.74, and 0.70.
Platted lots in the existing Deer Meadows development and Grand View
Acres are all larger than 1.0 acre. The Westfield development has 35
platted lots which vary in size from 0.46 acre to 0.60 acre.
Data on the remaining subdivisions lot size were not available.
Those areas which are not currently developed are used for livestock
grazing and are expected to continue under this use until development
is deemed feasible by the land owner.
37
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Mountain Plains
The Mountain Plains subdivision is adjacent to the southern border
of the City of Spearfish. There are about 10 homes in the development,
all on individual disposal systems. There are currently 62 lots in the
development and an additional filing on an additional 600 acres has been
made. This area is expected to develop into larger lots of several acres.
Development is likely to be slow due to the much higher costs of development.
Christensen Drive
The Christensen Drive development is located southeast of the City of
Spearfish. The development consists of 28 residential units and two large
campgrounds. Sewage disposal is accomplished by individual, on-site
systems.
CLIMATE
The Study Area has a continental climate, experiencing extreme
fluctuations in temperature in both summer and winter. The summer and
winter annual average temperature is 46.5 F and 35.8 F, respectively.
Winds in the area are generally from the north-northwest at an average
velocity of 10 to 12 miles per hour. Spring and summer winds frequently
blow from the south-southeast with velocities up to 75 miles per hour.
The average annual precipitation is 20.2 inches. The highest monthly
precipitation occurs during April, May, June, and July. Most of the
seasonal precipitation occurs as short duration, high intensity thunder-
storms .
GEOLOGY
Nine geologic formations have been identified within the Study Area. (2)
The identified formations consist of recent alluvial deposits, old terrace
deposits, the Spearfish Formation, Morrison Shale, the Sundance Formation,
the Minnelusa Formation, Opeche Shale, Minnekahta Limestone and the Brule
Clay.
i
The recent alluvial deposits are found in the Spearfish Creek and
Higgins Gulch bottom lands. The alluvial material consists of silt,
sand, gravel, and cobbles. These deposits have a high permeability,
partially a consequence of their unconsolidated nature and also as a
result of historic stream channels. The old stream channels meandering
through the subsurface alluvium are confined to the broad bottom lands
of Spearfish Creek. It is within these recent alluvial deposits that
the City of Belle Fourche has located its water supply infiltration gallery.
Old terrace deposits occur as isolated outcrops along the edge of
the benches of the bottom lands. These deposits are of a similar material
as the recent alluvial deposits but are older. Because of the location
of these old terrace deposits relative to the Spearfish formation it is
thought that these areas may contain perched water tables which would
not be contiguous with other groundwater m the area.
38
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The Spearfish Formation underlies the alluvial deposits of the
major drainages of the Study Area. This formation is found to be the
dominant formation of the benches above the bottomland areas. The
Spearfish Formation is predominately a red siltstone, consisting of
red sandy or silty shale. Massive gypsum beds and stringers occur
throughout the formation and limestone outcrops are also found. There
are also areas of gravel and unconsolidated sand which may be remnants
of old terrace deposits. The Spearfish Formation is considered to be
a very impermeable material, having a low water yielding capacity.
The Morrison Shale is found on the uppermost areas of the Lookout
Peak area east of Spearfish. This formation has little significance
in this study because of its location.
The Sundance formation separates the Spearfish Formation and the
Morrison Shale in the eastern mountains of the Study Area. This is a
shale which has some sand beds within the formation.
The Minnelusa Formation consists of pink and white granular sand-
stones with limestone lenses and layers. Red shales, white sandstone
and interbedded limestone occur near the base. In some areas a thick
permeable sand is found at the top of the formation. This formation
surfaces in tne mountains south and southwest in the Study Area. This
material is permeable and where it outcrops serves as an area for ground-
water recharge. Groundwater of the Minnelusa is significant to the area
because of its good quality, its artesian characteristics and high yield.
The Opecne Formation is composed of red siltv and sandy shales and
may contain streaks of gypsum. The formation is found in the western
areas of the Study Area.
The Mmnekahta Formation is a massive gray and pink laminated lime-
stone. Solution caverns and sinks occur in the formation. This sedimentarv
layer is founa primarily in the southwest areas of the Study Area, under-
lies the Spearfish formation, and is more permeable than the Spearfish.
The Brule Clay is a remnant formation that is considered to be in-
significant to this study. The formation occurs in the southeast corner
of the Study Area.
The general dip of the geologic formations is northeast and varies
from one to three degrees. A generalized geologic cross-section is
illustrated on Figure £-1. An idealized stratigraphic section of these
formations is also indicated on Figure 4-1.
In the context of water quality management and tne use of absorption
fields for seDtic tanks, key geologic considerations include the aepth
to bedrock, the potential for groundwater recharge, and soil type.
39
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I I ALLUVIUM
I' 1 ALLUVIUM-faHAVEL
KWWXWVj olo rtHHACt oteoaiT
ffflmilD SUHOAHCt
^ 7 /I SPtANMSH
fl < l> MIN NEti All IA
f\\"\*Vj OKtCHt
» \ MINNtLUiA
ITOuj
XJUul
FIGURE 4-1
GENERALIZED GEOLOGIC CROSS - SECTI ON
SOUTH QU AftrEM SECTIONS J.4.3.C. T CM , H 2E.
Q3xj3s
SECT ION 4
1
SECTION J
-------
The following summarizes the location of subdivisions as they relate
to the identified geologic formation.
Spearfish Creek Alluvial Valley
Weiss-West developments - recent alluvial deposits
Upper Higgms Gulch
Hardy - recent alluvial deposits
MacKaben No. 1 - recent alluvial deposits ana the Spearfish
formation
MacKaben No. 2 - older terrace deposits and the Spearfish
formation
Deer Meadows - recent alluvial deposits and the Spearfish
formation
Deberg-Fuller - recent alluvial deposits and the Spearfish
formation
Grandview Acres - older terrace deposits and the Spearfisn
formation
Westfield - older terrace deposits
Old Tmton Road - Minnekanta Limestone
Mountain Plains - Minnekahta Limestone
Chnstensen Drive - Spearfish Formation
SOILS
The U. S. Soil Conservation Service (SCS) has completed the survey
program necessary to map and interpret the soils of Lawrence County. (6)
Within the Study Area a total of 36 soils have been identified. The soils
map and the soils descriptions are currently unpublisned. However, the
unpublished soils maps and interpretations were made available from the
South Dakota State Planning Bureau (SDSPB). The detailed soils data
contain several variables relative to land development and use including
water management, soil ana water features (surface and groundwater),
suitability for sanitary facilities, building site development, physical
and chemcial properties of soil, soil use as a construction material,
crop and pasture production, recreational development, engineering
properties, windbreaks and environmental plantings, woodland management
and productivicy, and wildlife habitat potentials. For the purpose of
this Study those variables pertinent to urban/suburoan development and
associated wastewater disposal were evaluated and presented in Appendix A
of the Draft EIS.
41
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Land development oucside the City limits of Spearfish has been pre-
dominately north and northwest, with some development west and southwest.
The developments have occurred on many different types of soils, some
suitable to residential use and some having suitability constraints.
The following is a summary of soils that occur in the various sub-
areas .
Spearfish Creek Alluvial Vallev
Weiss-West
The Weiss-West developments are located in an area which consists of
four major soils:
Barnum silt loam
Barnum silt loam, channeled
Swint silt loam
' St. Onge loam
All four soils are susceptible to occasional flooding and have been
determined to have severe limitations for septic tanks, sewage lagoons,
and building site development.
Upper Higgins Gulch
Hardy
The Hardy development is located on the transition area from trie
eastern edge of Section 32. It is situated on the following four soils:
Vale silt loam, 0 to 2 percent slopes
Vale silt loam, 2 to 6 percent slopes
Tilford silt loam, 6 to 9 percent slopes
Nevee silt loam, 6 to 9 percent slopes
The Hardy development is located on the transition area from bottom-
lands to the bench area. The Nevee soils have low strength and buildings
may require foundations and footings designed to deal with potential
problems to prevent structure damage. The remaining soils are well suited
for building. Slow percolation of the Vale, and Nevee soils may require
that septic tank absorption fields be enlarged. Absorption fields in the
Nevee soil may not be feasible m places due to a shallow depth to Dearoctc
(40 to 60 inches) which can outcrop in this transitional area between the
alluvium and the bench area.
42
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MacKaben No. 1
The MacKaben No. 1 subdivision is located on Che southside of Inter-
state 90 in the southeast quarter of Section 32. The subdivision is in
the Higgins Gulch drainage and Higgms Gulch crosses through the northern
edge of the subdivision. There are four soil types in the subdivision,
these include:
Winetti cobbly loam
Tilford silt loam, 2 to 6 percent slopes
Tilford silt loam 6 to 9 percent slopes
Vale silt loam, 2 to 6 percent slopes
The Tilford soils found in the MacKaben subdivision are well suited
for both building sites and septic tank leach fields. The Vale soil is
suited for building but it is suggested by SCS that septic tank leach
fields be enlarged due to slow percolation rates. The Winetti soil is
identified as unsuited for building sites and sanitary facilities because
of the potential for flooding and seepage problems.
MacKaben No. 2
The MacKaben No. 2 subdivision is located in the southwest quarter of
Section .. and part of the southeast quarter of Section 6. There are 15
to 20 residential units in the subdivision. There are 6 soil types found
in the subdivision:
Barnum silt loam
Rekop-Gypnevee-Rock outcrop complex, 15 to 50 percent slopes
Nevee-Soearfish-Rock outcroo complex, 9 to 40 percent slopes
Swmt silt loam
Vale silt loam, 2 to 6 percent slopes
Nevee silt loam, 2 to 6 percent slopes
The Barnum soil is generally not suited for building sites and
sanitary facilities due to the potential for occasional flooding. The
snallow depch to bedrocs, low strength, and presence of soluble gypsum
nake the Rekop-Gynevee-Rock outcrop complex undesirable for building sites
and septic tank leach fields. Building sites and sanitary facilities
should be located on the lower slopes of the Nevee-Spearfish-Rock outcrop
complex. If buildings are constructed on this unit proper design of
foundations and footings snould occur to help prevent structure damage
43
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caused by the low strength of these soils. Septic tank absorption fields
should be located on the Nevee soils if possible. Enlarging the filter
fields helps overcome the slow percolation rate. The potential for
occasional flooding may render the Swint soil undesirable for both build-
ing sites and septic tanks, while the Vale soil is well suited for build-
ing sites but enlargement of septic tank leach fields may be required to
overcome the slow percolation rate. The low strength of the Nevee soil,
slow percolation rate and depth to bedrock may limit development on the
soil.
Deberg-Fuller
The Deberg-Fuller subdivision is located in the southeast quarter of
Section 5. There are 20 residences in the subdivision. The four soil
types found in the subdivision include:
Nevee-Spearfish-Rock outcrop complex, 9 to 40 percent slopes
Tilford silt loam, 2 to 6 percent slopes
Tilford silt loam, 6 to 9 percent slopes
Vale silt loam, 0 to 2 percent slopes
The Nevee-Spearfish-Rock outcrop complex is best suited for develop-
ment and septic tanks on the lower slopes of the unit. Proper design of
foundation and footings helps prevent structure damage caused by the
low strength of these soils. Septic tank absorption fields should be
located on the Nevee soils where possible. Enlarging the filter field
helps overcome the slow percolation rate. The Tilford soils are well
suited for both building sites and septic tank absorption fields. The
Vale soil is well suited for building sites but septic tank absorption
fields may require enlarging to overcome slow percolation rates.
GrandView Acres
The GrandView Acres subdivision is located in the northwest quarter
of Section 5 and contains 12 residential units. An unnamed intermittent
creek runs through the center of the subdivision. The principal soil types
which occur within the subdivision are:
Nevee-Spearfish-Rock outcrop complex
Tilford silt loam, 2 to 6 percent slopes
Tilford silt loam, 6 to 9 percent slopes
Vale silt loam, 0 to 2 percent slopes
Vale silt loam, 2 to 6 percent slopes
Nevee silt loam, 2 to 6 percent slopes
44
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Residential development on the Nevee-Spearfish-Rock outcrop complex
should be located on the lower slopes in this unit. Proper design of
foundations and footings helps prevent structure damage caused by low
strength of these soils. Septic tank absorption fields should be located
on the Nevee soils and the fields should be enlarged due to slow percola-
tion rates. The Tilford soils have no constraints for development. The
Vale soils are well suited for development but for septic tanks it is
recommended that enlarged absorption fields be built to offset slow
percolation rates. Nevee soils are not well suited for building due
to the low strength of the soils, slow percolation rates, and depth to
bedrock.
Westfield
Located in the northeast quarter of Section 8, the Westfield develop-
ment consists of 15 units. There are three soil types in the subdivision.
These soils are:
Winetti cobbly loam
Tilford silt loam, 2 to 6 percent slopes
Tilford silt loam, 6 to 9 percent slopes
The Winetti soil is not suited to building sites or septic tanks
because of the potential for flooding and seepage. However, the Tilford
soils are suitable for both building sites and septic tanks.
Old Tinton Road
The Old Tinton Road, west of Spearfish, has undergone limited develop-
ment. There are currently 10 to 12 residential units in this area. These
units are constructed on the following soil types:
Vale silt loam
Paunsaugunt-Rock outcrop
The major constraints for development on these soils include slow
percolation rate and potential shallow depth to bedrock for septic tank
absorption fields. Enlarging the size of the absorption field helps
overcome slow percolation.
Mountain Plains
The Mountain Plains subdivision is located in the southern part of
Section 22. There are about 10 residences in the development. There
are three major soil types in the area and include the following:
Paunsaugunt-Rock outcrop complex
Vanocker-Citadel association
Citadel association
45
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Steep slopes, stoniness and shallow depth to bedrock make the
Paunsaugunt-Rock outcrop complex unsuited for building sites and septic
tanks. Steep slopes, and an associated potential for soil slippage
makes the Vanocker-Citadel association unsuited for development. The
Citadel association can be built on if measures are taken to overcome
the potential for shrinking and swelling of this soil. Enlarging the
septic tank absorption field helps overcome slow percolation. SCS
suggests that if buildings and septic tanks are constructed, they should
be located in the lower part of the landscape where slopes are less
steep.
Christensen Drive
There are few homes in the Christensen Drive development and two
campgrounds. These developments have occurred on the following soils:
Nevee-Spearfish-Rock outcrop complex
St. Onge, loam
Vale, silt loam, 2 to 6 percent slopes
Vale, silt loam, 6 to 9 percent slopes
The Vale silt loams are well suited as a site for building with
the following precaution; septic tank absorption fields may need to
be enlarged to help overcome the slow percolation rate. Residential
development on the Nevee-Spearfish-Rock outcrop complex should be
located on the lower slopes of this unit. Proper design of founda-
tions and footings helps prevent structure damage caused by low strength
of these soils. Septic tank absorption fields should be located on the
Nevee soils and the leach fields should be enlarged due to slow perco-
lation rates. The St. Onge loam is susceptible to occasional flooding
and has been determined to have severe limitations for septic tanks,
sewage lagoons, and building site development.
WATER QUALITY CRITERIA AND STREAM CLASSIFICATION
The State of South Dakota has promulgated surface water quality
standards pursuant to the Clean Water Act. Numeric criteria have been
established for 28 parameters/constituents to result in achieving 12
beneficial uses. Beneficial uses of all streams in South Dakota are
designed for irrigation and wildlife propagation and stock watering.
Within the Study Area only Spearfish Creek and Higgins Gulch are designated
for additional beneficial uses. Spearfish Creek from the Redwater River
to the Homstake Hydroelectric Plant discharge is designated for domestic
water supply, cold water permanent fish life propagation, Immersion
recreation water, and limited contact recreation waters. Above the
Homestake Hydroelectric Plant to the Study Area boundary Spearfish Creek
is designed for cold water marginal fish life propagation and limited
contact recreation. Higgins Gulch from its confluence with Spearfish
Creek to the Study Area boundary is designated for cold water permanent
fish life propagation and limited contact recreation.
46
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WATER QUALITY
Surface and groundwater quality have been monitored extensively
throughout the Study Area. The principal sources of water quality
data are:
U.S. Geological Survey-Water Resources Division
U.S. Environmental Protection Agency
South Dakota Department of Water and Natural Resources
Special Studies
The most comprehensive data, which concentrates on the area of
the Higgins Gulch-Spearfish Creek confluence are available from a series
of special studies. These studies have resulted in the identification
of water quality problems in the surface waters of Higgins Gulch, and
Spearfish Creek, and in the groundwater of the alluvium which is the
source of the Belle Fourche water supply.
Coliform bacteria has been the critical water quality parameter.
Total and fecal colifonns are biological indicators of pollution. These
organisms^ serve as indicators for the presence of potentially hazardous
waterborne disease. Fecal coliform constitute about 90 percent of the
coliforms discharged in fecal matter whereas total coliforms account for
organisms naturally originating in soil, grain, and decaying vegetation.
The presence of fecal contamination is a recognized means of indicating
a potential hazard for human consumption. A high total coliform popu-
lation is also a suspicious symptom but not a specific indication of
fecal pollution. Other significant water quality parameters which have
been monitored include: chloride, nitrate, sodium, and total dissolved
solids (TDS).
Water quality problems were first identified at the Belle Fourche
infiltration gallery in 1967. Sporadic contamination was reported
from 1967 to 1977. Consistent contamination of the gallery was reported
in the last half of 1978 but during 1979 no contamination was reported.
In addition, a shallow well at the mouth of Christensen Drive has been
abandoned for domestic use due to coliform contamination.
Surface water quality data for coliform bacteria are the most
comprehensive for 1978. Spearfish Creek and Higgins Gulch have had high
coliform counts during the summer and fall of 1978.
Groundwater flows down Higgins Gulch into the Spearfish Creek Alluvial
Valley. In the area south of the infiltration gallery, the groundwater
moves in a northeasterly direction from Higgins Gulch into the gallery area.
The gallery area is also recharged from surface water from Spearfish Creek.
Higgins Gulch surface drainage is also recharging the groundwater as
evidenced by surface flows disappearing into the permeable streambed above
the gallery area (1).
47
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Studies at the City of Belle Fourche's infiltration gallery in the
fall of 1978 indicate that the depth of the groundwater varies from one
foot to over ten feet below the surface. These data were collected in
the fall, and therefore may not reflect the seasonally high groundwater.
Well log data for areas outside the gallery area indicate that the depth
to the static water table range from 15 to 25 feet below the surface.
In 1979 a special investigation was conducted to further quantify
groundwater levels in the area. (1) Water levels south of Interstate
90 (Upper Higgins Gulch) were found to be greater than 15 feet below
the ground surface. North of the Interstate groundwater became shallower
with the highest water levels recorded around the Belle Fourche infiltra-
tion gallery in the Spearfish Creek Alluvial Valley.
The increase in the number of septic tank-leach fields associated
with development in the Higgins Gulch area has been suspected as the
cause of the water quality problems identified at the Belle Fourche
infiltration gallery. However, recent studies have demonstrated that
percolation through 120 centimeters (cm) (4 feet) of soil appears to
be sufficient to minimize the possibility of groundwater pollution by
fecal coliform or viruses (coliphages) from septic effluent disposal (15).
Concentrations of chloride, nitrate, sodium, and .TDS in the Study
Area are not high enough to warrant a concern for water use, they do
indicate that septic tank effluents are entering the groundwater of
the Study Area. This situation is anticipated since soil absorption
fields usually do not change mineral concentrations.
Sewage disposal by septic tanks and absorption field is practiced
at the West Development and by one home in the Weiss Development which
are within a few hundred feet of the infiltration gallery. These systems
are located in the same alluvial deposits that the City of Belle Fourche
has their infiltration gallery.
All of the remaining outlying areas accomplish sewage disposal by
on-site systems, primarily conventional septic tanks followed by soil
absorption fields. The closest concentration of developments outside
of the Spearfish Creek Alluvial Valley using septic systems are in
the Higgins Gulch area, about three miles away from the gallery.
These developments are located on the Spearfish Creek bench areas.
Soils, according to SCS, are of a clay-loam and because of their slow
permeabilities are not suited for septic tank leach fields unless the
leach fields are enlarged.
Septic tank systems suspected of failing were identified using
aerial imagery. Two of the systems suspected as failing were confirmed
as actual failures and 13 were identified as potentially failing during
wet periods. These 15 systems were identified through surface man-
ifestations (lush vegetation over leach field) indicating tight,
impervious soils which are inhibiting effluent percolation.
48
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Further analysis of the water quality data from selected stations
indicate that there is a correlation between rainfall events (monitored
at the Homestake Saw Mill) and coliform counts in Higgins Gulch, Spear-
fish Creek, the Spearfish Creek Alluvial Valley, and the Belle Fourche
infiltration gallery.
The selected monitoring stations are shown in Figure 4-2. Data
from these monitoring stations and precipitations recorded at the Home-
stake Saw Mill are presented in Tables 4-2 through 4-6 for the summer
and fall of 1978. From this information the following correlations and
conclusions are made:
20 out of 29 of the total coliform samples collected in the Spear-
fish Creek Alluvial Valley (infiltration gallery, Cundy drain)
were associated with rainfall events.
31 out of 33 of the fecal coliform samples collected in the
Spearfish Creek Alluvial Valley were associated with rainfall
events.
Total coliform counts in Higgins Gulch were generally higher
after rainfall events.
Fecal coliform counts in Higgins Gulch do not exhibit a defined
trend. Counts ranged from 5 per 100 ml. to 276 per 100 ml.
Total coliform data in Spearfish Creek were insufficient to
evaluate.
Fecal coliform counts in Spearfish Creek ranged from less than
3 per 100 ml to 370 per 100 ml and were generally higher after
rainfall.
Supporting data presented in Appendix A indicate that total
coliform counts in the springs of the Spearfish Creek Alluvial
Valley are higher when the monitoring was preceded (within 43
hours) by a rainfall event.
Fecal coliform counts in the groundwater monitored outside of
the Spearfish Creek Alluvial Valley indicated no contamination.
EPA concludes that the historic contamination of the Belle Fourche
infiltration gallery and the Spearfish Creek Alluvial Valley in the
vicinity of the infiltration gallery has been caused by stDrm events
carrying coliform bacteria off the land surface via runoff. The con-
centrations of coliform vary with land use within the drainage, rainfall
intensity, and frequency of rainfall. Typically a rainfall event will
49
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FIGURE 4-2
WATER QUAUTV MONITORING STATIONS
Spearfish
Creak
Alluvial '
Belle Fourche
Infiltration —
Gallery
LEGEND
Developing Areas In
Study Area
• Selected Monitoring
Stations
HK
1/2
1/4
HCj.
Mountam-
Chnstansen \
}fDrive. I
50
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I^a;
6
9
10
11
L2
13
U
IS
16
17
18
19
20
21
22
2)
24
25
26
27
28
29
30
31
TABLt 4-2
PKEC1PIIATI0N AND Stl ECTLO WATtK QUALITY DATA (JUNL 1978)
Hir.ClNS t.ULCH SPEAHF1SII CKbbK
CAl I ERV C1IMDY DRAIN
-------
Day
I
2
3
4
5
6
7
8
9
10
11
12
1)
14
IS
16
17
16
19
20
21
22
2)
24
2S
26
27
2 b
29
30
31
1ABLE 4-3
PKLCIPITATION AND SELECTED WAltK
-------
F>jy
1
2
3
4
5
6
7
8
9
JO
11
12
13
14
IS
16
17
16
19
20
21
22
23
24
25
26
27
28
29
30
31
TAB1E 4-4
I'RLC I PI TAT I ON AND SLI.EC1 tl> WATER QUALITY DATA (AUGUST 1978)
HIGL1NS GULCH
SPEAKFlSil CHEEK
Pr
-------
TABU 4-5
HU.C1P1TA110N AND SEIECTLD WATER QUALITY DATA (SEFTDMEIL I97fi)
II1CCINS CUtCII
SPEAHF1SH CHEEK
Day
Total
Col I forn
Fecal
Col1forn
ClMPTf DttAlH (C)
Total Fecal
Collform Co 11 f oris
Total
CotIfora
_i!U_
Fecal
Col I form
im.
Total
Colifora
Fecal
ColIfora
<"*)
Total
Colifora
(lnclicb)
-------
1
2
3
4
S
6
7
a
9
10
11
12
13
14
IS
16
17
16
19
20
2)
22
2)
24
25
26
27
2B
29
3D
31
TAbLE 4-6
FKbCllMTATION AND SEItCTED HATER QUAI 1TY DATA (OCTOBER 197fl)
__ UIHCINS CULCII
SFtARFJSH CHEEK
P nc IpUat Ion
Tot (i 1
Col 1fora
Feral
Col J Fori
CWfflf DRAIN (C)
00
Totfl I
Col 1f orb
Tccal
Col Ifora
Tui al
Col lfona
Ti-cal
Col J forn
-QlU-
Tok al
Culiforo
>-ecal
Cot 1 form
Total
Col lform
F«cal
Co)lfora
_Oi_
Tot-al
Coliforn
Fecal
Coll form
(14) (UP) (DP) (SW)
FccbI Fecal Fecal Fecal
ColiforD CoUfoia Coljforo Col lform
(Incht-b)
it 100 ml 1/1 DO nl 0/100 al f/100 ml 0/100 ml f/IOOml f/lOOwl #/100 ml 1/100 al 9}100 ml »/100 ml 0/100 ad #/100ml f/lOOnl J/100 al 1/100 al
0 JO
0 04
0 IB
0 02
10
136
10
* Prcc 1|>I tul Ion Tt.(»orLud at llomubtakc iauwlll
L LulllOUCtS
-------
initially flush the surface, delivering high concentrations to surface
waters. The contaminated material will be generated by both developed
and undeveloped land and is commonly referred to as nonpoint source
contamination.
As the runoff moves down the drainage surface water elevations
rise. Groundwater elevations in the gallery area will increase due to
the increased water flowing in Spearfish Creek and Higgins Gulch. As
the groundwater elevation rises the potential for short-circuiting of
the septic tank absorption field in the West subdivision increases,
thus potentially contributing to the coliform contamination that has
been carried into the groundwater from the surface water. Because
of the defined movement of the groundwater in the alluvial material
the infiltration gallery became contaminated.
Field reconnossiance to identify the source of coliform contam-
ination in the well at the mouth of Christensen Drive (Miller Ranch)
indicated that the source of the well contamination is likely caused
by development in the Christensen Drive alluvial valley upstream of
this well. Septic tanks in this area are suspected as failing sea-
sonally, and those in the shallow alluvium of the valley bottom are
probably the contributing factors along with nonpoint sources in con-
tamination of this well. The contamination of this shallow aquifer
is attributable to the small confined characteristics of the alluvial
valley which is underlain by impervious soils.
At this time no public health hazards or groundwater contamination
are identified in the Mountain Plains area or Upper Higgins Gulch
relative to septic tank systems. The Mountain Plains area does have
a high potential risk of contaminating groundwater aquifers if con-
ventional septic systems are used to dispose of wastewater as develop-
ment density increases.
The approval and installation of the systems must be monitored on
an individual site basis. The ultimate success or failure of on-site
disposal systems will be determined by the Lawrence County Planning and
Zoning Commission, and the Northern Hills Sanitarian.
In summary, the findings indicate that septic tank systems are
a feasible means of sewage disposal in areas outside the City of Spear-
fish exept for the Spearfish Creek Alluvial Valley near the Belle
Fourche infiltration gallery and the Christensen Drive Alluvial Valley.
Because of the impermeable soils, the absorption fields in the Upper
Higgins Gulch area should be constructed larger than the State code (7)
requires and the systems may potentially function as evapotranspiration
systems as opposed"to the conventional leach field systems.
56
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FLOODPLAIN
Federal Executive Order 11988 (8) mandates that floodplain management
be an integral part of all planning efforts that are Federally funded
which will potentially encroach on a flood-prone area. For the Study
Area, three documents are available which address the floodplain of
Spearfish Creek and Higgins Gulch (9, 10, 11):
Flood Insurance Study City of Spearfish South Dakota
Lawrence County
Land Capability Maps, Lawrence County
Flood Hazard Boundary Map, Lawrence County, South Dakota
The Flood Insurance Study for the City of Spearfish covers all significant
flooding sources affecting the City of Spearfish.
The Spearfish Land Capability Study, and the Lawrence County South
Dakota Flood Hazard Boundary Map (Figure 4-3) present information on flood
hazards in Lawrence County. However, neither of these documents is
sufficient for floodplain management or land use decision making. The
Spearfish Land Capability Study identifies flood hazards as they relate
to the flooding potentials for soil mapping units defined by the Soil
Conservation Service. This information does not account for drainage
basin or other hydrologic features. The Flood Hazard Boundary Map
(Figure 4-3) produced by the Flood Insurance Administration was developed
using a discharge flow of 2500 cubic feet per second (cfs) in Spearfish
Creek and 600 cfs in Higgins Gulch. The value in Spearfish Creek is
below the 100 year flood flows calculated by the U.S. Army Corps and
values used in Flood Insurance Study for the City of Spearfish. Presented
in Table 4-7 is a comparison of flood discharge values for Spearfish Creek.
Review of the values presented in Table 4-7 indicates that the flood
discharge value for Spearfish Creek beyond the Corporate limits of Spear-
fish is very conservative and actually represents a flow equivalent to
a flood less than the 50-year flood event. Consequently, the current
flood hazard boundary map should not be used in floodplain management
planning. Proper floodplain management should restrict development
within the 100-year floodplain which corresponds to a Spearfish Creek
discharge of 7460 cfs.
57
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.! .SUH^U^L—1
V
FIGURE 4-3
LAWRENCE CO . SO
IUWICC 1>UI
fiooo uzjho sounoi«r
58
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TABLE 4-7
DISCHARGE VALUES FOR SPEARFISH CREEK
Flooding Source Drainage Peak Discharges
and Location Area (cfs)
(mi^) 50 year 100-year
Spearfish Cr. @
Conf. w/Hungry 168 4.4501'2 7,3701,2
Hollow Gulch
Spearfish City 172.2 4,5101,2 7,4601,2
Limits
Hungry Hollow
Gulch <3 Conf. 2.7 6502 1.2902
w/Spearfish Cr.
Spearfish Cr 168 2,500^
1. U. S. Army Corps of Engineers, Personal communication, 3 December 1979
2. U. S. Department of Housing and Urban Development. Flood Insurance
Study, City of Spearfish, South Dakota Lawrence County, Preliminary,
March 29, 1979.
3. U. S. Department of Housing and Urban Development. Flood Hazard
Boundary Map, June 1977.
FLOODPLAIN MANAGEMENT
The National Flood Insurance Program was established with a primary
purpose of encouraging State and local governments to adopt floodplain
management programs. Studies such as the Flood Insurance Study for the
City of Spearfish, include sufficient detail of the flood boundary to
develop floodplain management programs. However, the flood hazard
boundary map of Lawrence County does not provide adequate or correct
flood boundary information to aid in floodplain management. In view
of this lack of detailed information, Lawrence County is not constrained
in implementing floodplain management programs.
The Lawrence County Zoning Ordinance defines a Floodplain District
for planning purposes. (12) Section 3.6 of the Zoning Ordinace states
that, "the intent of the Floodplain District is to prevent loss of life,
property damage, and protect public health through restriction of
development in those areas subject to flood".
The permitted uses of property and buildings in the District are to
be used only for the following purposes:
Crop and pastureland and similar agricultural purposes.
Open spaces not requiring a closed building.
Fences.
59
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Storage yards for equipment and material properly anchored
to prevent moving into bridges or other debris catching areas.
Recreational and open space areas not requiring a closed building.
Sanitary and storm sewer drains shall be equipped with 3afety
valves capable of being closed to prevent backup of sewage and
storm waters into building or structure.
The County Planning Commission can issue a Conditional Use Permit
for developments in Floodplain Districts. These conditional uses include:
Residences, providing they are located and constructed ahove the
elevation of the floodway.*
Agricultural buildings, such as bams and stables, provided they
are located above the elevation of the floodway.*
Currently, adequate information is not available to define the
elevation of the floodway along the major streams in Lawrence County
outside the City of Spearfish. Therefore, no Conditional Use permitS
should be issued for development until the County develops criteria
and procedures for floodplain/hazard identification.
The primary reason for the identification of flood hazard areas is
to cause the human use of such areas to be compatible with hazards. There
are many valuable uses which can be made of known hazard areas and also
ways to minimize or eliminate the hazard. In the alluvial valley along
Spearfish Creek, the floodplain coincides with a high groundwater table
making septic tank disposal unsuitable. Prevention of residential
development within the 100 year floodplain would eliminate the combined
risks of possible loss of life and property or potential groundwater
contamination. Guidance for techniques, methods and procedures for
establishing floodplain restrictions in Lawrence County are presented
in Chapter V. tierer to EPA's decision in Chapter 1 which
requests Lawrence County to implement acceptable floodplain regulations
and requires a grant condition with the City of Spearfish and the Spear-
fish Valley Sanitarian District to develop an acceptable floodplain
protection ordinance.
CULTURAL RESOURCES
On July 11 and 12, 1978 the South Dakota Archaeological Research
Center conducted a linear pedestrian survey along the interceptor routes
identified in the original Facilities Plan. (2) Associated with this
work, a record search was also conducted.
The interceptor corridors surveyed had, for the most part, been
radically disturbed previously and were also overgrown with heavy
vegetation. These conditions resulted in a ground surface visibility
of less than five percent overall.
* Height above floodway is not specified but typically is one foot.
60
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The record search revealed a number of historic sites in the vicinity
of Spearfish which are on the National Register of Historic Places. These
sites include:
Episcopal Church of All Angels
Frawley Historic Ranch
Lown Home, William Ernest
Spearfish Historic Commercial District
Halloran-Mathevs-Brady House
Spearfish Fishery Center
The record search did not reveal any prehistoric sites in or near
the proj ect areas.
No prehistoric cultural material was located in the course of the
survey. Since none of the National Register sites in the Spearfish
vicinity are located within the proposed project areas they should not
be affected by any of the proposed alternatives.
There is a special concern, however, with regard to the McGuigan
farmstead. It is located in the SW%, NW*s of Section 4, Township 6 North,
Range 2 East. The house has not been nominated to the Register at this
time. The possibility exists, however, that it is eligible for nomination.
It is concluded that there are no known prehistoric or historic
cultural resources which may be affected by the construction of the
alternative facilities except the McGuigan farmstead. If the house or
immediate area is to be affected, then steps will be taken to evaluate
its eligibility to the National Register of Historic Places. Construction
of the proposed interceptors however will not be on or near the McGuigan
farmstead.
Cultural material, historic and prehistoric, may have gone undetected
due to heavy vegetation or lack of surface indications. If any such
material is discovered in the course of construction, work should cease
in the affected area and the State Historical Preservation Officer should
be notified.
61
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ENVIRONMENTAL CONSEQUENCES
OF THE ALTERNATIVES
CHAPTER 5
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CHAPTER 5
ENVIRONMENTAL CONSEQUENCES OF THE ALTERNATIVES
Environmental consequences of the proposed alternative systems must
be viewed within the framework of the pertinent impacted features of the
Study Area. It must be recognized that an environmental system is dynamic,
with adjustments and compensations continually being applied to maintain
the systems at a desired level. The management of water quality is-a
means of achieving environmental control which creates the need for
adjustments throughout associated systems (i.e., land use, socio-economic,
etc.). If the adjustments or tradeoffs among the water quality management
alternatives are to be viewed openly, they must be displayed 'in such a
manner that the key environmental consequences of every option are under-
standable to the various interests responsible for the decision-making
process.
IMPACT ASSESSMENT CRITERIA
During the development of the updated Facilities Plan and this EIS
four development areas and six wastewater management alternatives have
been identified. To comparatively evaluate the consequences of these
alternatives in the context of the critical environmental features of
the Study Area it is necessary to define the impact assessment criteria.
Costs
The costs associated with the wastewater management alternatives are
for capital investment, annual operation and maintenance (0 & M), total
annual costs, and monthly user costs. Costs have been updated from the
original Facilities Plan.
Under the Clean Water Act, EPA can provide 75 percent of capital
costs for wastewater plant upgrading, collection linesi or sewer inter-
ceptors based on current grant eligibility guidelines. If the proposed
system qualifies as an innovative or alternative system, the Federally
funded share can be 85 percent. Sewer line sizes are based on the
maximum population expected in 40 years in the service areas.
Reliability
Reliability of a particular alternative is assessed in terms of
the various components ability to respond to external variables over
the planning period. External variables include:
temperature, and other climatic parameters
process upsets, such as flooding
failure of other subsystem components, such as soil saturation
ability to provide acceptable wastewater and water quality
management
65
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Flexibility
Flexibility of the various alternatives is assessed relative to
the ability of the system to accommodate possible future growth or
expansion and associated wastewater management requirements.
Energy
Energy conservation is becoming a more stringent factor in selecting
the most cost-effective alternative. The impact on energy consumption
is assessed in terms of the relative energy demands of the various com-
ponents of the given alternative including such items as transmission
and pumping neVds.
Water Quality
The existing water quality data base is reasonably extensive for
the Study Area. However, data is not available to quantitatively deter-
mine the future water quality benefits of the alternatives. Further,
the identified water quality problems are associated with nonpoint sources
and the wastewater management alternatives do not treat this problem.
Each of the sub-areas has different water quality goals which EPA
believes are pertinent for determing the proper wastewater management
strategy. These various goals are:
Spearfish Creek Alluvial Valley - protect surface and ground- v
water, insure protection of the Belle Fourche infiltration
gallery.
Upper Higgins Gulch - correct nonpoint source problems.
Mountain Plains - protect the groundwater recharge area.
Christensen Drive - protect surface and groundwater.
Nonpoint source management is addressed separately in this Chapter.
Cultural Resources
The potential impact to cultural resources, archaeological and
historical, are a direct consequence of construction. Identification
of cultural resources, their significance and mitigation measures
necessary to protect and/or salvage them must be evaluated in Federally
funded projects. Cultural resources are not currently of concern based
on survey data.
Foreclosure of Future Options
The commitment of land and other resources resulting from the
implementation of an alternative may foreclose the County's options
for future land use management or wastewater management.
66
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Funding
The alternatives must be considered in terms of the eligibility of
the various component costs. This is not only as the costs relate to
the EPA construction grants process but other agency participation and
the local share. Alternatives for funding are presented separately in
this Chapter.
System Manageability
System manageability is defined as the level or degree of effort
and control with the City, County, and/or other regulatory agencies
must exercise to sustain effective implementation and operation of any
alternative. Manageability also includes the enforcement requirements
of applicable regulations. Other factors include: staffing require-
ments, financial arrangements, and regulatory agreements.
ALTERNATIVE IMPACT ASSESSMENT
Spearfish Creek Alluvial Valley
No Action
Costs have not been developed for this alternative. The principal
area that will be affected is the West Subdivision. The continued use of
septic tank - leach field systems in this area will result in a low
reliability of wastewater management. The soil absorption field will
be susceptable to short circuiting during periods of high groundwater
and potentially susceptable to flooding.
From the wastewater management perspective this option provides for
good flexibility to accommodate future growth. However, when considered
in the context of water quality management and development m a potential
flood prone area this alternative has poor flexibility.
Direct energy costs associated with the alternative should be
confined to periodic septic tank pumping and would consequently be low.
The protection and enhancement of water quality is not likely to
be realized under this option. This developing area is identified as
a probaole contributor to tne biological contamination of tne Belle
Fourche infiltration gallery. Consequently, the no action alternative
will not provide corrective measures for this situation.
The no action alternative does not foreclose future options relacive
to water quality management. It does not provide protection or contribute
to the accomplishment of water quality goals.
The no action alternative may foreclose future land use management
objectives for flood prone areas by establishing a precedent of allowing
development in such areas. Funding criteria are not applicable to the no
action alternative.
67
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Holding Tanks
Holding tanks offer a slightly higher reliability in the Spearfish
Creek Alluvial Valley than the no action alternative. Holding tanks
mitigate the problems identified with septic tank leach field. They
are susceptible to the upset problems such as high groundwater con-
ditions "floating" them out of the ground. Flooding problems are
reduced significantly but seepage and infiltration into the tank is
possible. A holding tank is not likely to be approved by the State
Department of Water and Natural Resources unless it is preceded by a septic tank
or a chemical treatment unit. The original Facility Plan recommends that
holding tanks have 5,000 gallon capacity. Assuming three people per
dwelling generating 300 gallons per day the tanks would require pumping
twice a month. This frequency of pumping will require a rigid maintenance
schedule and variations in wastewater generation among homeowners further
reduces the reliability of holding tanks.
The flexibility of this alternative relative to water quality man-
agement is very good. It is expected that residential growth could be
accommodated through the use of holding tanks. However, like the no
action alternative this option has poor flexibility when viewed in the
context of water quality management coupled with land use management of
flood prone areas.
Energy costs associated with this alternative are going to be high
because of the energy requirements associated with operation and mainten-
ance (bimonthly pumping requirements). Properly operated and maintained
holding tanks will eliminate the domestic wastewater contributions to
the contamination of the Belle Fourche infiltration gallery. Therefore,
the water quality objectives of this area would be met.
Relative to future water quality management strategies for the
area this option does not foreclose future options. This option may,
however, foreclose future land use management objectives. Continued
development in the Spearfish Creek Alluvial Valley potentially will
establish a precedent of endorsing development in flood prone areas.
The manageability of this alternative is low. To insure successful
water quality management strict operation and maintenance must be adhered
to. Land use management of the Spearfish Creek Alluvial Valley is also
poor under this alternative.
Funding assistance for this alternative is r.ot available from
Federal and State agencies. This is because the systems as proposed
do not satisfy State septic tank regulations (7). Funding by local
agencies is not likely to be available for the same reason. Therefore,
this alternative is dropped from further consideration for all development
areas.
Evapotranspiration
Evapotranspiration systems provide a low to moderate level of
reliability relative to wastewater management. The original Facility
Plan states that these systems will be susceptible to disruption due
68
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co winter temperatures during which pumping will be required. It is
estimated that a 5,000 gallon septic tank will require pumping approxi-
mately twice a month. This feature coupled with potential problems
associated with high groundwater and flooding reduces the overall
reliability of the systems.
This alternative provides good flexibility to accommodate future
growth in terms of wastewater management requirements. The energy costs
will be higher than those associated with conventional septic tank systems.
Evapotranspiration systems with properly sealed beds will achieve
the water quality goals for the Spearfish Creek Alluvial Valley area.
Future options for this area relative to water quality management
should not be constrained. However, options for comprehensive land use
management and planning may be foreclosed. The use of on-site systems
potentially will encourage unconstrained development.
Federal and State funding is available for evapotranspiration
systems. Certain criteria must be met in order for units to be elig-
ible. Systems in flood prone areas may not be eligible for certain
types of funding.
System manageability is good for water quality management but poor
for land use management. Current limited enforcement of septic tanks
systems could result m improperly installed systems which would result
in jeopardizing water quality.
Gravity Collection/Pressure Interceptor
The reliability of this alternative is very high as a means of
collecting and conveying wastewater from this area to the city's
wastewater treatment facility. The most vulnerable component of this
system is the pump stations. Proper seal of the system will eliminate
infiltration/inflow problems present with the high groundwater level.
System flexibility is expected to be fair. The system will be sized
to accommodate ultimate development based on current plats. However,
future developments may not be able to use the system due to capacity
constraints. The interceptor line could be used as a growth management
tool.
Energy requirements of this system will be moderate. Primary energy
demand will be the lift station.
This alternative achieves water quality goals of the area. The
collection/interceptor would convey wastewater out of the area. This
feature is very desirable to insure protection of groundwater, surface
water and protection of the Belle Fourche water supply.
This alternative aoes foreclose future wastewater management alter-
natives for tne developments in the area. They will be committed to
tne system for the design life. This alternative also can foreclose
69
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certain Land use options but can service as a growth management
tool.
Manageability of this system is very good since a sewering agency
will be responsible for the system. There is a higher probability that
residents will connect into the system when financial incentives of a
sewering agency are necessary. (i.e. homes within 200 feet will tie
into the system when a sewering agency has enforcement powers).
Pressure Effluent System
This system has a moderate level of reliability. Reliability of
this alternative is decreased because of maintenance requirements
associated with the septic tank effluent pumps and the package plant.
The system is not expected to be highly susceptable to upsets. However,
the package plant would be vulnerable to floods. This can be mitigated
at additional cost.
The flexibility of this system to accommodate future wastewater
flows and strategies is fair. The hydraulic capacity of the package
plant and interceptor will determine ability to handle flows. This
system commits the area to this system during the life of the facilities.
Energy consumption will be moderate to high. In addition to energy
requirements associated with the package plant and pumps for effluent,
septic tank pumping will consume additional energy.
Water quality goals of the Spearfish Creek Alluvial Valley can be
accomplished. However, disruption of operation of the package plant
slightly reduces the reliability of continued achievement of water quality
protection.
Options for future water quality management are foreclosed until
the life of the system components are met. Similiarly, land use option
could be foreclosed if the hydraulic capacity of the system is used to
control development.
Funding is available from Federal and State agencies. These options
are discussed separately in this Chapter.
System manageability is moderately good. Some form of sewering
agency will be required for operation and maintenance of the system.
The least manageable component of the system is associated with septic
tank maintenance. If septic tank maintenance is handled by the serving
agency then good manageability is expected.
Gravity Collection/Package Plant
This system has a high degree of reliability for collecting and
conveying wastewater. The package plant is the primary component chat
decreases the overall reliability. This component is the most vulnerable
to system upsets such as flooding.
70
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The flexibility of this system is expected to be fair. Flexibility
constraints are associated with hydraulic capacity of lines.
Energy consumption will be moderate and consist of operation and
maintenance requirements of the pump station.
Water quality objectives for the Spearfish Creek Alluvial Valley
are achieved with this alternative. This system will protect ground
and surface water, and the Belle Fouche infiltration gallery.
Future options for water quality management strategies will be
foreclosed for the life of the systems.
Hydraulic capacity of the system can function as a growth management
tool. This may result in foreclosing certain land use management options.
System manageability of this alternative is very good. The respons-
iblity of the system will be placed with an identified sewering agency.
A single management agency with financial responsibilities generally
prove very effective in operating and maintaining sewer systems.
The alternative assessement for the Spearfish Creett Alluvial Valley
is summarized in Table 5-1.
Upper Higgins Gulch
No Action
The reliability of the no action alternative for the subdivisions
in the Higgins Gulch area is very good. It has been demonstrated that
most of the septic tank systems are functioning properly wnen installed
according to State regulations. Reliability is decreased due to under-
sized leacn fields and tight soils. This has resulted in the identifica-
tion of seasonal failures. Because of the scattered nature of develop-
ment in this area particular subdivisons will have to consider specific
site conditions (l. e. Westfield Subdivision will require design features
that consider perched water table conditions). Septic tank systems
have not proven vulnerable to climatic upsets. However, overall reli-
ability depends on the owners satisfying requirements for periodic
pumping.
Good flexibility is achieved. Future growth in the area 1= con-
strained only relative to minimum lot size requirements as defined in
the State regulations.
Energy consumption is low for this alternative. Energy demands
will be confined to the periodic pumping requirements during tne life
of the individual system.
Studies and analysis conducted as part of the EIS indicate vater
quality problems for the entire Study Area are associated vit'n nonpoint
sources. The continued use of septic tanks in Upper Higgins Gulch will
achieve water quality goals and protect surface and groundwater.
71
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TABLE 5-1
IMPACT EVALUATION MATRIX
SPEARF [Sll CREEK ALLUVfAL VALLEY
EVALUATION CRITERIA
ALTERNATIVE
No Action
Evapo-
L ranspirat ion
GravIty
CoLJ ect ion/
Pressure
I nterceptor
Pressure
Ef fi uent/
Package
PI anL
Gravity
CoL1ection/
Package
PlariL
RELIABILITY
Low-subject to treat-
ment disruption froin
high ground water and
flooding.
Low to moderate -
subject to disruption.
Moderate to high
0 & M requirement.
Very high - removes
wastewater from area.
Pumps vulnerable to
disruption.
Moderate - nuninia]
potential for disrup-
tion. Septic Lank and
pump maintenance high.
Package plant subject
to disrupt Ion.
Illgh-removes waste-
water from area
FLEXIBILITY ENERGY
Accommodates future Low
growLh, but encour-
ages development in
flood hazard area.
Lack of controls
aid flexibility.
Very good - Moderate
accommodates future
growLh. Lack of
control aids
flexibili ty.
Fair - hydraulic Low to
capacity may limit moderate
growth, if land use
and septic tank
regs. enforced.
Fair -
above
same as
Fair to moderate -
hydraulic capacity
will limit growth
wiLliin 200 feet of
system
Low
WATER QUALITY
Future options open for
wastewater management.
Continued flood area
development may fore-
close future land use
opt ions.
Achieves water quality
goals of area if
installation is
correct (i.e. sealed
leach field). ,
Achieves water quality
goals of area.
Moderate Achieves water qualiLy
to high goals of area.
Achieves wastewater
management goals
but not nonpoint
management goals of
area.
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TABLE 5-1 (COW]" l))
EVALUA'l I UN CRITERIA
ALTERNAT I VE
No All Jon
Evapo-
t ransp i ra L ion
Gravi Ly
CollecL ion/
Pi essure
Interceptor
FUTURE OPTIONS
Future opt Ions open
tor wat>Lewater
management. Contin-
ued flood area devel-
opment may foreclose
future land use
opt fons.
Same as above
Foreclose future
wastewater manage-
ment optjons and
use management
opt Lous may be
forec Losed.
SYSTEM
MANAGEABILITY
Poor - no conLrol
of Land ut>e or
wastewater Jn an
area conLrIbuLing
to "rob I ems
FaLr - pot entia]
for improper in-
stallation threatens
goals of Lhe area.
Very good - would
require sewering
agency. Coordination
wiLli City may be
required.
"COSTS 1 ($)
TOTAL CAPITAL
MONTHLY
ANNUAL O&M USER
3,000
25.00
25.92
36,000'
174,000"
109,870
4,020,
19,4 30"
5,000
62.98
103.49"
30.67
2
EQUIVALENT
COST
311.00
7,452.00,
36,016.00"
14,149.00
Pressure
KffIuenL/
Package
PI anL
Same as above.
Ora v I Ly
Col IecLion/
Pac kage
Plant
Same as above
Fair to good - 71,380
would require sewer-
ing agency. Requires
0 & M of septLc
tanks and package
plant Coordination
with C LLy may be
requlred.
Good - would require 90,010
sewering agency. O&M
ma J n I y 1 i in I Led to
package plant. Coor-
dination wltli City may
be required.
9,000
45.41
8,000
40.29
15,804
15,972.00
1. CosLs developed by ScoLL Engineers, Fac 11 iLies Plan UpdaLe.
2. Homes built before December 1977 - 85 percent Federal Fund.
J. Homes built after December 1977 - 0 percent Federal Fund.
4. (jibLs lor upgrading fail ing and suspecLed falling systems are presented in Table5-5,
-------
The no action alternative does not foreclose any future option
relative to wastewater management or land use. Constraints on minimum
lot sizes is not viewed as a constraint for development.
Based on current management practices, the overall system manage-
ability of this alternative is low. This is a consequence of the lack
of enforcement of State septic tank regulations at the County level.
EvapotranspiratioR
Reliability of evapotranspiration systems in the Higgins Gulch area
is moderate to good. Several of the suspected seasonal failures iden-
tified using aereal imagery are functioning as evapotranspiration systems.
This is because the leach fields are too small for the tight soils which
reduce percolation. The original Facility Plan indicates that these
systems will experience disruption due to harsh winter conditions and
will require pumping four months of the winter. If these systems are
constructed with a mound system climatological upsets will be
more probable, however, it is easpected that these systems can function
properly in the Upper Higgins Gulch. Winter maintenance requirements
reduce the reliability of these systems.
This alternative for Upper Higgins Gulch provides a good level of
flexibility to accommodate future growth and wastewater management.
Energy requirements associated with this alternative will be high
if winter pumping is required. Energy requirements will be higher than
those associated with conventional septic tanks.
Evapotranspiration systems will contribute to achieving wastewater
management goals of the Upper Higgins Gulch area.
This alternative is not expected to foreclose future options for
wastewater management or land use management in this area. However,
this will be predicated on the enforcement of State regulations for on-
site systems at the County level.
Funding assistance for evapotranspiration is available. Certain
criteria must be met m order for units to be eligible.
System manageability is good for wastewater management providing
State regulations are enforced. As a land use management tool this
alternative has poor manageability.
Gravity Collection/Interceptor
The reliability of this system is very high as a means of collect-
ing and conveying wastewater from this area to the city's wastewater
treatment facilities. Reliability is enhanced by gravity conveyance of
wastewater.
System flexibility is fair to moderate. The system would be sized
to accommodate growth for the planning period, however, hydraulic
74
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capacities may limit development within 200 feet of line (State require-
ment for mandatory connection to system).
Energy requirements for this alternative will be low. No major
energy use components are associated with this system.
The alternative achieves wastewater management goals of this area.
Collection and interceptor lines foreclose future options for waste-
water management during the design life of the system. The area will be
committed to the system and may experience land use/development con-
straints due to hydraulic limits.
Manageability of this system is very good since a sewering agency
would be responsible for operation and maintenance of the system.
Presented in Table 5-2 is a summary of the impacts for alternatives
considered in the Upper Higgins Gulch sub-area.
Mountain Plains
No Action
The continued use of septic tank-leach field systems in Mountain
Plains will result in a low to moderate reliability of wastewater/water
quality management. Use of these systems is extremely site specific
and reliability is contingent upon the presence of acceptable soils. The
fractured bedrock, shallow soil, and groundwater recharge areas m
Mountain Plains reduce reliability of these systems.
These systems provide low to moderate flexibility to accommodate
future growth because of site specific conditions. The site conditions
can limit the future growth of the area provided State regulations are
enforced.
Direct energy costs will be low to moderate due to costs/consumption
associated with transport and pumping.
Water quality goals and wastewater management objects will be jeop-
ardized under the no action alternative. The proliferation of septic
tanks and conventional leach fields in this area threaten the groundwater
quality.
The no action alternative does not foreclose future options relative
to wastewater management. However, should these systems result in ground-
water contamination they could foreclose land use/development options.
Funding from EPA is not likely to be available for this alternative
in the Mountain Plains area due to the sensitivity of the area.
System tnanageaoility is currently poor and has the potential of
continuing. This lack of system manageability was recently demonstrated
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TABLE 5-2
IMPACT EVALUATION MATRIX
UPPER H1COINS GULCI!
ALTERNATIVE
EVALUATION CRITERIA
RELIABILITY
FLEXIBILITY
ENERGY
HATER QUALITY
No Action Very high - care must
be taken to insure
proper design and instal-
lation conform to state
regs. Low potential for
on-site system disrup-
tion.
Very good -
accomodates future
growth. Lack of land
use controls aids
flexibility.
Low
Achieves water quality
goals for wastewater
management but does
manage nonpoint source
problems of area.
Evapo-
transpiration
Moderate to high -
must be designed & in-
stalled to State regs.
Subject to disruption
during winter. Moderate to
high 0 & M requirements.
Same as above.
Moderate Achieves wastewater
management goals but
not nonpoint management
goals at area.
Cravity
Col lection/
Interceptor
Very high-renioves waste-
water from area.
Fair to Moderate-
hydraulic capacity
will limit growth
within 200* of system.
Low
Achieves wastewater
management goals but
not nonpoint manage-
ment goals of area.
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TAI11.E 5-2 (CONT'D)
EVALUAT TON CRITERIA
ALTEKNATI VE
FUTURE OI'TIONS
SYSTEM
MANACEAI5IL1TY
COSTS'' ($)
TOTAL CAPITAL
ANNUAL O&M
MONTHLY
USER
EQUIVALENT
COST
No Action
Eva po-
t I'ailSp I l"dL LOll
Future opL ions for
wastewater and iand
use management
open.
Same as above.
f.ow-CurrenL lack of
enforcement of
regulations does
noL insure proper
des Lgn & installation.
Same as No Act Lon for
Upper IILggins Gulcli
J,000.00
25.00
J24.000.002 36,180.00^
576,000.00 64,320.00
25.92
62.98,
103.49"
311.00
67,064.00
1 19,224.00
Cravity
Co IJ ection/
I nlere epLo r
Forecloses future
wastewater manage-
ment options within
200' of system.
Land use may also
he foreclosed.
Very good - requires
sewering agency.
Coordination with
CiLy may be required
389,700.00
6,000.00
16.88
18,541.00
19,908.00
1. CobLb developed by Scolt Engineers, Facilities Plan Update.
2. Homes l)ni IL before December 1 977 - 85 percent Federal Fund.
J. Ilomcb builL afLer December 1977 - 0 percent Federal. Fund.
Costs for upgrading faU Ing and suspected falling sysLems are presented in Table 5-5.
4
5. I nLereept'or only.
-------
to EPA. A recently constructed home in Mountain Plains was permitted
by the Northern Hills Sanitarian to install an illegal on-site sewage
treatment system. The system was installed, so that an effluent dis-
charged down a dry drainage way. No consideration was given to the
requirements for a National Pollution Discharge Elimination System
(NPDES) permit, water quality, or public health. EPA, upon inspection
of the system, requested that an NPDES permit be requested. The request
was subsequently denied and the discharge will be eliminated by constructing
a mounded leach field. EPA is waiting confirmation that this situation
has been corrected.
Evapotranspiration
Evapotranspiration systems can achieve a high degree of reliability
in achieving water quality goals and the protection of the recharge area
if raised, sealed beds are incorporated into the system. The four month,
winter pumping requirement reduces the reliability of these systems.
Flexibility of these systems is considered to be very good relative
to future growth and wastewater management.
Winter pumping requirements will increase the energy requirements of
this alternative. Energy consumption will be higher than conventional
septic tanks.
Water quality goals and wastewater management of the Mountain Plains
area can be accomplished with this alternative. Of the on-site alternatives
evapotranspiration systems provide the greatest insurance for protecting
the recharge area.
Future options for wastewater management and land use management will
not be foreclosed with this alternative.
Federal and State funding is available for evapotranspiration systems.
Certain criteria must be met in order for units to be eligible. In the
Mountain Plains area it will be necessary to insure that the aquifer re-
charged in this area is protected. This can be accomplished with proper
design, construction, and operation.
System manageability can be good. Current limited enforcement of
State regulations for on-site systems could result in improperly installed
systems which could jeopardize water quality.
Gravity Collection/Interceptor
Reliability of this alternative is very high as a means of collecting
and conveying wastewater from Mountain Plains to the city's wastewater
facilities. Gravity conveyance of the wastewater enhances the reliability
of this alternative.
78
-------
The flexibility of this alternative is fair to moderate relative
to wastewater management. The hydraulic capacity of the system would
accommodate growth during the planning period. However, the proposed
systems would only serve Mountain Plains No. 1. The potential exists
that capacities could not be designed into the system for Mountain
Plains No. 2 without over designing the system. This feature reduced
the overall flexibility of the system to meet future growth requirements
for wastewater management.
Energy requirements for this alternative would be low. No major
energy using components are associated with this system.
Wastewater management and water quality goals are achieved with
this alternative.
This alternative will foreclose future options for wastewater manage-
ment in Mountain Plains No. 1 and may constrain options in Mountain Plains
No. 2 during the design life of the system. The area will be committed
to the system and may experience land use/development constraints due to
hydraulic limits.
System manageability of this alternative is very good. A sewering
agency will be required and would have operation, maintenance, and en-
forcement responsibilities for the system. Presented in Table 5-3 is-
a summary of the assessment for Mountain Plains.
Christensen Drive
No Action
Reliability in terms of wastewater management is low for the no
action alternative. It has been documented that groundwater contamination
in tne area has occurred and is a consequence of septic tank systems in
the alluvial valley. Above the alluvial valley (Chris' Campground) it
is suspected seasonal failures are occurring due to overloading the leach
field, improper construction, and inadequate soils. Further, septic
tank systems in the alluvial valley are subject to having their leach
fields short circuited during periods of high runoff and flooding.
Flexibility of this alternative to accommodate future wastewater
management strategies is good. However, land use and development can
not be accommodated since septic systems with conventional leach fields
should not be allowed in new development in the area.
Direct energy costs will be low and primarily associated with
maintenance/pumping requirements.
This alternative will not accomplish water quality or wastewater
management goals of the Christensen Drive area. These systems in the
area contribute co the contamination of groundwater. No action will
provide no correction of this situation.
Under this alternative future options for water quality management
are not foreclosed. However, future land use ana development options may
be constrained. Without tne correction of water quality problems development
79
-------
ALTERNATIVE
RELIABILITY
No Action Low to moderate -
site specific
conditions will
determine vulner-
ability to upset-
ting treatment.
Evapo-
transpiration Moderate to high -
must be designed and
installed to State
regs. Subject to dis-
ruption during winter
Moderate to high 0 &
requirements
Gravi Ly
Col lection/
InLerceptor
Very high - removes
wastewater from
area.
TABLE 5-3
IMPACT EVALUATION MATRIX
MOUNTAIN PLAINS
EVALUATION CRITERIA
FLEXIBILITY ENERGY
Low to moderate - Low to
site conditions will moderate
dictate ability to
accomodate future
growth. Current lack
of controls aids
flexibility.
WATER QUALITY
May not achieve water
quality goals of area.
Proliferation of
development and lack
of installation conLrol
jeopardizes area goals.
Same as above Moderate Achieves water quality
goals of area. Systems
must be Installed
properly.
Fair to moderate - Low
hydraulic capacity
may not be sufficient
to accomodate future
development.
Achieves water quality
goals of area if future
development accomodated
-------
TAI5LE 5- i (CONT' I))
EVALUATION CKITERLA
COSTS ($)
ALTERNATIVE
No AcCion
Eva |>(>-
L ranspJ raL J on
(I r<.i v 1 Ly
Co I I ec L i on/
1nLei tepLor
I'UTURE OPTIONS
future wasLewdter
management, opt Lons
open. Land use
management, may be
foreclosed if slate
regs. not met.
Same as above.
Forecloses fuLure
wastewater manage-
ment opL Lons for
service area. Land
use opLion may be
f orecIosed.
SYSTEM
MANAGEABILITY
,Joor-'Jurrenl Lack
of enforcement
of regulations wouLd
1lkeIy continue.
[,nw-f!urrent lack of
enforcement of reg-
ulations does noL insure
proper design and instal-
lation. WLnLer 0 & M
must be insured.
Very good - requires
sewering agency. Co-
ordinaL ion with CLty
may be required.
TOTAL CAPITAL ANNUAL 06.M
J, 000
i2,000;
312,000"
JL9,750
25.00
1,340.00,
34,840.00"
2,500.00
MONTHLY
USER
25.92
48. 34
ECU rVALRNT
COST
311.00
63.002
103.49
2,484.00
64,580.00"
2,4 23.00;
26,70J.00"
L. CosLs ileveLoped by Scolt Engineers, I'aciliLy I'lan UpdaLe.
2. Homes built before December 1977 - 85 percent federal Eund.
J. Homes builL dUer December 1 977 - 0 percenl federal fund.
4. Costs for upgrading failing and suspecLed falling systems are presented In Table 5-5.
5. InLercepLor only.
-------
may be stopped since the no action alternative would perpetuate septic
tank systems in the area.
Minimal system management xs achievable with this alternative.
Current limited controls/enforcement of State regulations could result
in septic tanks being installed improperly in the area further aggrevating
water quality problems. Furthermore, land use controls may perpetuate
development if wastewater management controls are not enforced.
Evapo transairat ion
A low to moderate level of reliability is expected for wastewater
management under this alternative. Based on the assumption that winter
pumping would be required, reliability is reduced. The current lack of
enforcement related to design and installation of the systems further
makes the reliability questionable. In the alluvial valley disruption
is a potential problem due to flooding even if a raised bed is incor-
porated.
The alternative does provide good flexibility to meet wastewater
management of future development. However, as a land use management tool
the flexibility to direct and control future growth is poor.
Moderately high energy requirements are associated with this alter-
native. Identified winter pumping is the primary cause of higher energy
costs.
If these systems are properly installed and maintained, the water
quality objectives for Christensen Drive can be achieved.
Future wastewater management options should not be constrained by
implementing this alternative. Based on current trends on-site systems
may result in unconstrained development. Such a condition could fore-
close future development options.
Gravity Collection/Interceptor
This alternative has a very high degree of reliability as a means of
collecting and conveying wastewater in the Christensen Drive area. Re-
liability is reduced due to the seasonal variations anticipated due to
use of the two campgrounds. Reliability is enhanced because wastewater
will be conveyed by gravity.
Flexibility is fair to moderate. Hydraulic capacities may constrain
future growth, particularly if on-site systems are not encouraged. Be-
cause the system would be designed for only future development during the
planning period unanticipated development may not be accommodated.
Energy requirements associated with operation and maintenance would
be low. No energy using components are expected to be required in this
system.
Wastewater management and water quality goals will be accomplished.
Wastewater will be removed from the area.
82
-------
Future options for wastewater management will be foreclosed in the
area during the design life. The area will be committed to the system
as the wastewater management strategy. Hydraulic limits of the system
may foreclose future land use options.
The alternative provides a high level of system manageability. A
sewering agency will be required which will be responsible for operation,
maintenance, and enforcement elements of the system.
A. summary of the impacts identified for the Christensen Drive
alternatives is presented in Table 5-4.
COSTS
Cost estimates for the alternatives have been updated as part of
the update of the Facility Plan. The costs are presented in Tables 5-1
through 5-4. The no action alternative for all sub-areas does not have any
developed costs per se. However, the correction of identified and suspected
seasonal septic tank failures costs have been developed. Since these
improvements do not constitute a defined alternative it is assumed that
where identified water quality problems are not associated with septic
tank systems, the no action alternative would include these correctional
costs which are presented in Table 5-5.
83
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TABLE 5-4
I Ml'ACT EVALUATION MATRIX
CIIIUSTENSEN DRIVE
EVALUATION CRITERIA
ALTERNATIVE
No Action
RELIABILITY
Low-current treat-
ment is being dis-
rupted due to high
ground water and
soli/slope conditions,
FLEXIBILITY
Low to moderate -
Lack of enforcement
of Stale regs. would
aid flexibility to
accomodate future
growth
ENERGY
Low
WATER QUALITY
Does not achieve water
quality goals of area.
Evapo-
t runspl ration
Low to moderate -
subject to disruption.
Moderate to high 0 & M.
Must be designed and
installed Lo State regs.
Same as above.
Moderate Achieve water quality
goals of area. Must
be installed properly.
Gravity
Collection/
Lnterceptor
Very high -
removes wastewater
from area.
Fair to moderate - Low
hydraulic capacity
may not be sufficient
to accomodate fuLure
growth.
Achieved water quality
goals of area.
-------
TAIiLE 5-4 (CONT'D)
EVALUAT ION CKITEK1A
COSTS ($)
ALTEKNAT I VE
No AcLion
EU'I'UKE OPTIONS
Wa t> t ewa t e r mandge-
inent option open.
Land use/development
options may be fore-
c I oseil.
SYSTEM
MANACEAUILITY
Poor - Current
lack of enforce-
ment of regulations
wouLtl Ijkely
Liint i mie.
TOTAL CAPITAL"
3,000
ANNUAL O&M
25.02
MONTHLY
USEK
25.92
EQUIVALENT
COST
JJl.00
Evapo-
L I cl 11 b p I L" a l ion
Same db above
Low - CurrenL lack
of enforcement of
regulations does
iiol insure proper
debign and instal-
lation. Winter
O&M not manageable.
162,000
18,090.00
62.98
33,532.00
00
I'dv l Ly
Co I I u«. L I on/
I nLe riepLor
Eoreclobes future
wastewater manage-
ment op L Jons lor
service area. Land
use management may
be foreclosed.
Very good - requires
sewerang agency. Co-
ordination with CjLy
may be required.
89,390
11,805 (Kris'
Campground)
J,000.00 27 res.6.85
500.00 110.73
(Mountain View) 32.70
8,443
(Interceptor
Co 11ecL ion]
I. CosLs developed by Scott Engineers, Ear: ill Lies Plan UpdaLe.
I. Homes bulIL before December L977 - 85 percent Federal Eund.
J. CosLs lor upgrading failing and susper Led fail ing sybteins are presented in Table 5-5.
-------
TAOLE5-5
FAILING OR SUSPECTED SEASONAL FAILURES
Or LEACH FIELDS THROUGHOUT THE STUDTAREA
Present Size, Theoretical Proposed Size, Estimated Cost
(VERIFIED SEPTIC FAILURES)
Palmer Pearson No Leach Field Now has one built
Robert 01en
Size of Leach Field
Maximum Possible - 28C ft4
Probably less, 200 to 250
ft'
No Perc. data Is available for this
immediate area. Soils 1n area
Indicated to be 30-100 min/in.
Will use 30 min/in. 2
Area required about 250 ft./bedroom
250 ft2 = 50g ft2
2 bdrms x
Leach field probably needs additional 250 ft maximum or about 80 L.F.
80 L.F. x $6.00/L.F. = $480.00
Price Mound System
500 ft^ * 3 = 167 L.F.
No Pump Should Be Needed
Const. Cost = $2,000.00
(SUSPECTED SEASONAL FAILURES)
Robert Klumb
Size of Leach Field
About 100 L.F. of line
300 ft^ leach field
3 bdrms x 250 ft2 = 750 ft'
Leach field probably needs additional 450 ft^ maximum or about 150 L.F.
150 L.F. x $6.00/L.F. = $900.00
Same perc. data information as
Robert 01 en
SOURCE: Scott Engineers
-------
TAIJLL 5-5 (continued)
(SUSPECTED SEASONAL FAILURES)
Jack Delaney
Size of Leach Field
About 120' long, 20' wide
Looks to have 3 lines
About 720 ft^ Leach Field
Same perc. data information as
Robert Oien
3 bdrms x 250 ft^ = 750 ft
Leach Field 1s adequate, may need 10 L.F.
10 L.F. x $6„00/L.F. = $60.00
addition
Bob Koski
Not able to determine the exact
leach field, believed to be about
250 fr
Same perc. data information as
Robert Oien
J 2 2
2 bdmis x 250 ft* = 500 ft£
Leach field probably needs additional 250 ft^ or about 80 L.F.
80 L.F. x $6.00/L.F. = $480.00
Bob Hanson
About 118 L.F. of line
354 ft^ Leach Field
Many leach fields 1n area have
540 ft . Perc. test in lot nearby
which would be
charts show area
should be 30-100 min/in. Will use
15 min/in. or 190 ft /bdrm
showed?5 min/in
125 ft /bdrm. Soil
3 bdrms x 190 ft2 = 570 ft2
Leach field probably needs additional 210 ft or about 70 L.F.
70 L.f. x $6.00/L.F. = $420.00
Melvin Seymour
About 150 L.F. of line
450 ft leach field
Same Perc. data information as
Bob Hanson
4 bdrms x 190 ft2 = 760 ft2
Leach field probably needs additional 310 ft or about 103 L.F.
103 L.F. x $6.00/L.F. = $618.00
-------
TAIIl.!'. 5-5 (continued)
(SUSPECTED SEASONAL FAILURES)
R1ck Price Size of Leach Field Same perc. data Information as
About 103 L.F. of line Bob Hanson
309 ft leach field
3 bdrms x 190 ft2 = 570 ft2
Leach field probably needs additional 260 ft2 or about 87 L.F.
87 L.F. x $6.00/L.F. = $522.00
Curtis McKee About 110 L.F. of line Same perc. data Information as
330 ft leach field Bob Hanson
3 bdrms x 190 ft2 = 570 ft2
Leach field probably needs additional 240 ft2 or about 80 L.F.
80 L.F. x $6.00/L.F. = $480.00
Fred Fox 110 L.F. (Could be one or two lines) Leach fields in area have 600 ft2
330 ft2 to 660 ft2 leach field Data available for this general
area show perc rates to be 15 to 30
min/in. Soil charts show 30-100
min/1n?, will use 30 min/in. or
250 ft /bdrm.
3 bdrms x 250 ft2 = 750 ft2 2
Under worst conditions leach field might need 420 ft extension or 140 L.F.
140 L.F. x $6.00 = $840.00
2
Stan Allen 600 ft leach field Same perc. data information as
Fred Fox
3 bdrms x 250 ft2 »j 750 ft2
Leach field probably needs 150 ft additional or 50 L.F.
50 L.F. x $6.00 = $300.00
-------
TAI1I.E5-5 (Continued)
(SUSPECTED SEASONAL FAILURES)
Tom Freece Originally undersized Same perc. data information as
Leach £ield has L>een extended, Fred Fox
600 ft
3 bdrms x 250 ft2 = 750 ft2
_eecn field might need 150 ft additional or 50 L.F.
50 L.F. x $6.00 = $300.00
John Jeffery
106 L.{>. of line
318 ft leach field
No perc. data is available for this
immediate area. Soils charts show
perc. rates to be 30-100 min/in.
Owner indicated there was some gravel
in soil and perc. rate was definitely
not that slow. Will use 30 min/in
or 250 ft /bdrm.
2 bdrms x 250 ft2 = 500 ft2
Leacv field may need 180 ft addition or about 60 L.F.
60 L.F. x $6.00 = $360.00
Chris' Campground 140 total sites
20 complete hookups
1 bath house - 4 showers - 7 stools
1 bath house - 4 showers - 7 stools
1 laundry
#1 Leach Field 60 sites, 1 bath house
60 sites x 2 persons/site x 35 gal/person = 4,200 gal/day
Length of field approx. 660 L.F. or about 1,980 ft^
Will use 30 m1n/in. perc. rate, same as Jeffery
with perc. rate 30 min/in. = 0.9 gal/ft /day
4,200 gals ~ 0.9 gal/ft = 4,667 ft required
This drain field probably needs about 2,687 ft more or about 895 L.F.
895 L.F. x $4.00/L.F. « $3,580.00
-------
TAD I. IS 5—5 (Continued)
(SUSPECTED SEASONAL FAILURES)
11. Ch»"is' Campground (Continued)
#2 Leach Field 60 sites, 1 bath house = 4,200 gal/day
Length of field approx. 1,058 L.F. or about 3,174 ft2 + 1 dry well (63 ft2)
(ave. 4' dia., 5* deep)
Same perc. rate data.
Need about 2,625 ft2
This leach field probably needs about 1 ,430 ft2 or about 477 L.l".
477 L.F. x $4.00 = $1,908.00
$3 Leach Field
v£
Q
#4 Leach Field
20 sites, complete hookups
20 sites x 2 persons/site x 50 gal/person = 2,000 gal/day
Length of field approx. 130 L.F. or about 390 ft^ + 1 dry well (63 ft2)
Same perc. rate data.
2,000 gal/day * 0.9 gal/ft2 = 2,222 ft2
Need about 1,769 ft2 additional drain field or about 590 L.F.
590 L.F. x $4.00 = $2,360.00
House & Two trailers - 7 bedrooms
Same perc. rate data as John Jeffery 250 ft2/bdrm
Length of field approx. 260 L.F. or about 760 ft2 + 3 dry wells (63 ft2)
ave. 4' dia., 5* deep)
7 bdrms x 250 ft2 - 1,750 ft2
Increase leach field about 781 ft2 or about 260 L.F.
260 L.F. x $4.00 = $1,040.00
-------
TANLI'' 5-5 (continued)
(SUSPECTED SEASONAL FAILURES)
11. Chris' Campground (Continued)
#5 Leach Field 6 trailers - 12 bdrnis
Same perc. rate data as John Jeffery
Length of field approx. 250 L.F. or about 750 ft2 + 1 dry well (63 ft2)
12 bdrms x 250 ft2 = 3,000 ft2
Increase leach field about 2,187 ft' or about 729 L.F.
729 L.F. x $4.00 = $2,916.00
-------
FUNDING
Alternative Methods For Financing Alternatives
Financing wastewater collection facilities can be accomplished by
several methods. The selected method generally is based upon monies
available and equity among the users. Grants, loans and various other
methods should be investigated.
General Obligation Bonds
General Obligation Bonds are a form of bonded indebtedness which
allow the governmental entity to borrow funds for a public purpose to
benefit the general population within the jurisdiction of the local
government. The indebtedness is repaid at a prescribed rate, for both
principal and interest, from the general fund of the local government.
This form of indebtedness offers the government the highest degree
of flexibility, but also imposes a high degree of fiscal responsibility
upon the government to manage its general fund in a prudent manner to
allow retirement of the debt within the prescribed terms.
The limitations on such bonds and the procedures for their issuance
are regulated by the state constitution, state statutes, and, in the
case of home rule entites, by local charters.
Revenue Bonds
Revenue bonds enable the local government entity to incur indebtedness
for a special public improvement and to repay the obligation from revenues
derived from the improvement constructed.
As in the case of general obligation bonds, the limitations and
procedures for issuance of revenue bonds may be governed by state
constitution, state statutes, and/or local charters. Revenue bonds
generally contain bond convenants by which the local government agrees
to maintain and operate the improvement according to a prescribed plan
to insure the electorate that the improvement can, in fact, be self-
sustaining. Such improvements must be for a public purpose and within
the normal functions of the local government. Generally, all revenues
derived from the improvement must be applied directly to retirement of
the bonds and cannot be diverted to other purposes or uses.
The district boundaries may take the size and shape of the individual
subareas of the study area. The improvement district could be created
to finance only one element, such as water distribution, or it could
include sewage treatment, drainage, street improvements, parks, recrea-
tion, and other improvements within a given jurisdiction.
Special Assessments
A special assessment is a charge imposed by a local government upon
the owners of property specifically benefited by "local" public improve-
ment. The payment by the property owners of the assessment may be
accomplished by any of several plans to accommodate installment type
payments.
92
-------
The nature of the facilities which can be financed by this method
are limited to those that benefit the immediate locality and those
property owners who are being assessed as opposed to one which confers
a substantially equal benefit to the whole community or public-at-large.
As a general rule, the assessment to any particular property owner cannot
exceed the cost of the benefit the property owner receives.
Special assessment improvements are generally initiated by a petition
of the property owners directly affected ana, depending on the constitution,
statutes, and local charter limitations, usually require an affirmative
election by a majority of the property owners within the approved district.
Bank Loans
Short term bank loans are another source of capital funds. Limited
use of this source prevails because of the short term pay back period and
greater interest rates. However, this method could be used in conjunction
with connection fees to finance a portion of the recommended facilities.
Contributions
Contributions can be a very useful method to finance small projects
or to finance reports and studies which provide benefit to a limited
interest.
Connection Fees
Connection fees which are levied prior to a building permit being
issued. They are intended to be utilized for future improvements or for
repayment of bonds with the surplus to be utilized for capital improvements.
Annexation Fees
Annexation fees are levied in order to nelp pay for existing facilities
which are to be used by the annexed area.
Federal and State Loans and Grants
Several sources of federal and state loans and grants are available
under the appropriate conditions to assist m financial wastewater system
proj ects.
Public law 92-500 - amendments to the Federal Water Pollution Control
Act.
This program provides 75 percent grant assistance to counties,
cities, towns, and those special sewer and/or water districts
established under applicable state laws. The grant program
covers all phases of project development, from planning through
engineering and construction. The process is commonly referred
to as the "Step Process" and is divided into three phases.
Step 1 grants, or 201 facilities planning grants, provide for
the planning phase, including development of the plan of study,
evaluation of alternate methods of treatment and waste disposal,
93
-------
and resolution of the environmental issues addressed in the
study. Step 2 grants are preliminary design of facilities,
and Step 3 grants are for final design and construction. Each
step must be approved by the South Dakota Department of Water and
Natural Resources and EPA before the applicant can proceed to the
next step, be reimbursed for, or awarded a grant.
Under the construction grant program, wastewater treatment
facilities, interceptors, and collection systems are eligible
projects. The collection system however, is eligible only if
two-thirds of the houses in the area to be sewered were con-
structed prior to 1972.
Farmers Home Administration (FmHA) community facility loans,
water and waste disposal systems for rural communities.
Th.e Farmers Home Administration makes loans at 5 percent interest
for up to 40 years to communities under 10,000 population
or sanitation districts organized under applicable state
laws. Inquiry should be made through the FmHa county
supervisor. A preapplication conference is arranged and
application forms are provided for the potential applicant.
Proof that the applicant cannot obtain financing at comparable
or near comparable interest rates must be furnished. The
A-95 review process as explained in EPA Grant procedures
must be adhered to and comments become part of each application.
An environmental assessment must also be prepared. All appli-
cation processing is conducted through the county supervisor.
Wastewater treatment facilities, interceptor systems and collec-
tion systems are eligible for participation under this loan
program. It should be noted that this vehicle is being used
to finance collection systems where EPA is assisting with
planning and construction of wastewater treatment facilities.
The Community Facilities Loan Program has assisted countless
smaller communities throughout the nation with planning and
construction of their wastewater systems. Congressional authori-
zation and appropriation for this particular program have remained
at relatively high levels.
Grants can be made for up to 50 percent of project costs provided
grant funds are available. Traditionally, FmHA grant and loan
funds have been used together to bring the user costs in line
with current economics of comparable communities or districts.
Grants are processed in the same manner as loans and are applied
for simultaneously when grant funds are available or are expected
to be available through congressional authorization and appropriation.
Economic Development Administration (EDA) Grants and Loans for
Public Words and Development Facilities.
Cities, towns, and private or public non-profit corporations
located in designated EDA redevelopment areas are eligible for
94
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grant and direct loan assistance to plan, design, and construct
wastewater systems.
The public works grants rate is 50 percent of the project cost.
In instances where the area is determined to be a severely depressed
area, up to 80 percent funding is possible. Designated Indian
reservations are eligible for 100 percent assistance.
Long term, low-interest loans for up to 40 years may be made when
financial assistance is not otherwise available from private
lenders or federal agencies on terms that would permit accomplish-
ment of the project.
A prime qualification for this program is the project's ability
to fulfill a pressing need in the area, particularly in providing
employment opportunities, encouraging business or industrial
development, and benefiting long-term unemployed or members of
low income families.
A community or district can find out if they are in the properly
designated area for this program through county officials,
regional council of government staff, or the State EDA represen-
tative.
If eligible, the community must contact the State EDA represen-
tative and request a meeting to determine merits of the project
before preapplication. Preapplication conferences are held at
the regional offices and, if approved, all processing is handled
directly through the regional office. The project must also
be reviewed under A-95 procedures and an environmental assessment
made.
Farmers Home Administration (FmHA), Section 601 - Energy impacted
area development assistance program.
The objective of this program is to help areas impacted by coal
or uranium development activities by providing assistance for
the development of growth management and housing plans. They
also can assist in developing and acquiring sites for housing,
public facilities and services. An approved designated area
consists of a county, a group of counties, or a part of a county
which has been designated as an impacted area by the Governor of
the State and approved by the Secretary of Energy.
Up to 75 percent of the actual cost of developing or acquiring
sites for housing, public facilities, or services for which
financial resources are otherwise not available may be obtained.
The facilities include water and sewer connections and the
necessary water and sewer lines to housing and public facilities
sites.
Designation criteria is based on increases in eligible employment
and also on housing and public facility conditions.
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Department of Housing and Urban Development (HUD) Community
Development Act of 1974.
The Community Development Act of 1974 is an extremely broad and
all encompassing program which generally has eliminated all
categorical grant programs traditionally administered by HUD
by creation of a block grant delivery system. This system puts
the prime responsibility on the community and its elected officials
to determine community needs and objectives, especially as they
relate to the low income segment of the community. This includes
housing, public works, social concerns, etc.
The sum of $8.3 million has been authorized for South Dakota
for fiscal year 1980. The total is broken down into $2.4 million
for large metropolitan areas and $5.9 million for non-metropolitan
small cities. Spearfish is classified in the non-metro small
city category and would compete for the money allocated to that
account.
The grant is for 100 percent with no match required from the
community. HUD, however, will evaluate how the community is
supporting other community development activities. Public
works, including wastewater systems, are eligible projects.
A-95 procedures and public hearings must be carried out, and
responsibility for making an environmental assessment and
applicable decisions rests with the community and its elected
officials.
Current Course of Action
The Sixth District Council of Governments is currently conducting a
study to evaluate the potential of annexing seven areas surrounding Spear-
fish, including the Christensen Drive area. However, the City of
Spearfish has yet to take action to annex the Christensen Drive area.
The Spearfish Valley Sanitation District has recently annexed
the West Subdivision area.
Financial Options
As previously discussed there are several potential methods for funding
wastewater facilities. The final funding arrangements should result in
equitable user charges for the entire service area.
The grantee, Spearfish, is eligible for 75 percent funding of a new
wastewater treatment facility and associated interceptors. The remaining
25 percent will have to be financed by the city through bond sales, current
budget surplus, FHA, HUD, EDA or any other funding options available.
Outlying areas which are not part of the city or a sanitation district
must be annexed into the city or the existing Spearfish Valley Sanitation
District, or form a separate entity. If the areas are annexed into the
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city, EPA grant funds will be available to the areas. If a separate
entity is formed by an outlying area or annexation in the Sanitation
District is established, an agreement will have to be established with
the City of Spearfish whereby 75 percent funding of interceptors from
the entity to Spearfish is possible. The remaining 25 percent of the
interceptor and the collection system within the entity would have to
be funded by alternative means. Grants are available, depending on
conditions, to areas which have excessively high user fees. These
grants are available through Farmer Home Administration and Department
of Housing and Urban Development. Long-term low interest loans are
also available through Farmer Home Administration.
NONPOINT SOURCES
Nonpoint sources of pollution are identified as a primary cause
of surface water and alluvial groundwater* pollution in the Spearfish
201 planning area. Nonpoint pollution is defined as the accumulated
pollutants in the stream, diffuse runoff, seepage, and percolation
contributing to the degradation of the quality of surface and ground-
waters. The sources of nonpoint pollution within the Study Area originate
from two distinct types:
Natural
Man related
Natural nonpoint sources are the result of the natural, unaltered,
environmental conditions of a drainage basin. These include naturally
occurring mineralized springs and seeps, and the natural geologic, soil,
vegetal, and faunal materials that are eroded from the land by precipitation.
These natural sources are difficult to quantify and control. Where these
sources can be isolated, such as springs, some specific management practices
could be implemented in hopes of reducing the pollutant loads reaching
surface water.
These natural sources are not thought to be the major water pollution
sources in the Study Area.
Man related sources of nonpoint pollution are a direct consequence of
human activities within the Study Area. These activities either disrupt
the natural environment causing an acceleration in the rate of natural
pollutants entering streams, or create a pollution source by introduction
of foreign material into the natural landscape.
Man related sources of nonpoint pollution m the Study Area are
related to the following activities:
Urban Stonnwater Runoff
Agriculture (livestock confinement/concentration areas)
Construction (urban and suburban expansion)
Septic tank systems
^Alluvial groundwater is water in an aquifer composed of unconsolidated
natenal deposited by water action. This water is recharged by surface
water and is hydraulically connected to the surface water system.
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Additional sources of nonpoint pollution in Lawrence County but
outside the boundaries of this Study Area include:
Silviculture
Mining
Various State and Federal agencies have adopted best management
practices (BMP's) for controlling nonpoint pollution from human activities.
The Sixth District Council of Governments, whose planning area includes
the 201 Study Area, have identified nonpoint source BMP's that are
applicable to their planning area.
The BMP's are defined as a practice or combination of practices that
are determined by a state after problem assessment, examination of alter-
native practices, and appropriate public participation to be practicable
and most effective in preventing or reducing the amount of pollution
generated by diffuse sources to a level compatible with water quality
goals (13). Where practicable, BMP's should consist of nonstructural
controls, such as good land management. Structural controls should be
implemented when nonstructural controls are ineffective.
The goal of nonpoint source pollution control is to reduce/eliminate
pollutant material from being delivered to surface water. This process,
in many cases, involves the control of erosion and sediment. Sediment
from erosion is identified as the major pollutant in terms of volume
within the Sixth District planning area (13). However, within the 201
Study Area, biological contamination from agriculture and urban storm-
water runoff is identified as the pollutant creating the major water
quality problems.
Nonpoint sources manifest themselves throughout the region and
therefore BMP's for control of the known nonpoint sources will be summarized.
The ability of any agency to implement nonpoint source controls will be
dependent upon the availability of funds and manpower. Detailed BMP's
and maximum soil loss guidelines will be developed by the Conservation
Districts on a district by district basis to reflect local conditions.
Lawrence County must work with the local district in developing these
practices. Additionally, coordination and implementation of BMP's to
correct the nonpoint sources identified within the 201 Study Area should
occur between the City of Spearfish, Lawrence County, and the local
Conservation District.
Controlling Nonpoint Sources of Pollution
The following sections summarize the various management practices
that are recognized as being effective in controlling nonpoint sources
of pollution in the area. Many of the management practices that have been
inventoried are utilized in construction, forest management, mining, and
urban management planning as well as in agriculture. Management practices
which are followed by an asterisk (*) are applicable to correcting the
identified nonpoint sources in the 201 Study Area. Those practices which
are followed by a dash '-) are identified as useable in the Sixth District
208 planning area (13). Costs are presented when found available for a
specific management practice.
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Urban Stormwater Runoff
Studies on the urban stormwater runoff problem have increased in the
last several years since the passage of the Clean Water Act in 1972. These
studies have resulted in considerable information regarding the quality of
urban stormwater. The contaminant load, or the chemical composition of
urban stormwater is extremely variable. This is a consequence of the
myriad of activities in and around an urban area. Typical parameters
monitored to assess urban stormwater quality are: biochemical oxygen
demand, chemical oxygen demand, volatile suspended solids (indicator of
organic pollution), suspended solids (indicator of organic pollution),
suspended solids (indicator of particulate matter), and coliform bacteria
(indicators of biological contamination).
Based on information evaluated during the Sixth District 208 Study,
the City of Spearfish is rated as having the second highest priority
for nonpoint source pollution. The first priority is Rapid City. The
water pollution potential from urban stormwater from Spearfish is rated
as moderate (14).
Three primary approaches to abatement of stormwater runoff are:
Source control to remove the contaminants before they are picked
up by the runoff water.
Treatment of storm and combined sewer flows to remove pollutants
before discharge.
A combination of the above two management practices.
The following practices are recommended for dealing with urban runoff
m the Sixth District planning area.
Institute a street sweeping program, preferably using a vacuum
sweeper to insure removal of fines (*,-).
Alter peak runoff flow by designing new parking lots to temporarily
slow or store runoff (*,-).
Employ parks and other open space as temporary storage (*,-).
Install small retention ponds or modify the storm sewer system
to provide off-line storage. Stored sewage and surface runoff
should then be fed back into sewerage lines for treatment at
the wastewater treatment plant (*,-). (Note: Treatment of
surface runoff at a wastewater plant is not a grant eligible
item under EPA funding criteria).
Encourage private property owner cooperation with goal of storing
stormwater on-site for controlled release (*,-).
Increase distance of flow to stream by constructing diversion
structures (*).
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Install holding tanks with controlled release devices (*).
New pavement construction consisting of porous asphalt pavement
for roadways and parking lots.
Periodic perforation of public and private lawns to increase
infiltration.
Temporarily store stormvater on flat or slightly sloping roofs
equipped with detention drains.
Implementation of any of these management practices will require
evaluation for cost and treatment efficiency on a small scale.
Agricultural
Agricultural practices in the 201 Study Area are separated into the
following three categories:
Livestock confinement/concentration area
Dry land/range land
Irrigated land
Strategies presented for controlling nonpoint pollution from these
categories are taken directly from the Soil Conservation Service (SCS)
Standards and Specifications for the respective management practice.
Many of these management practices are applicable to other activities
and should not be viewed as only agriculturally oriented. Following
each agricultural categories is a list of the management strategies
pertinent to nonpoint source controls for the activity.
The definition, scope, purpose, and/or applicability of each practice
are available from the EPA. Specific design must be developed on a case
by case basis. General design criteria may be found in the various SCS
Technical Studies. Management practices should be developed for each
farm or ranch individually. This should occur in cooperation with
appropriate agencies.
Livestock confinement/concentration area
Water quality is seldom seriously impacted by those animals that are
grazing on well managed range land or on well maintained hay pastures.
The primary situations where livestock may adversely impact water quality
are related to concentrated feeding areas, the overuse of pasture land,
and concentrated access on surface streams.
Livestock confinement areas along Higgins Gulch are one of the
primary sources of water pollution in the Study Area. The bacteria and
organic compounds entering surface and alluvial groundwater from these
areas are contributing to the contamination of the Belle Fourche water
supply.
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Feedlots are classified as point source dischargers if they contain
over 1,000 head of livestock. Smaller feedlots that drain directly to a
stream are also required to have discharge permits.
The primary best management practice for feedlots is the selection
of a proper location and the use of a nonpolluting method of waste disposal.
When trying to decide if an area is a feedlot or just a pasture, a
benchmark that can be used is that if the animals have used the area
heavily enough to kill the grass, it is a feedlot. Winter feeding
sites, where the hay is spread on a field for the livestock, are normally
act considered to be feedlots.
Management Strategies*
Agriculture Waste Management System (312-1)
Deferred Grazing (352)
Disposal Lagoon (359-1)
Diversion (362-1)
Drainage Field Ditch (590-1)
Fencing (382)
Floodwater Diversion (400-1)
Holding Pond (425-1)
Livestock Exclusion (472)
Pipeline (516-1)
Structure for Water Control (587-1)
Trough or Tank (614-1)
Well (642-1)
Dryland/Rangeland
Erosion and the resultant soil loss is the principal nonpoint source ¦
of water pollution from dryland farming and grazing. Man-induced accel-
erated erosion costs agriculture millions of dollars annually. The South
Dakoca Division of Conservation estimates that nutrient loss alone exceeds
200 million dollars per year in South Dakota (13).
The Sixth District Council contracted with the Soil Conservation Service
to analyze erosion and sediment yields from nine watersheds and to rec-
ommend management priorities best suited for sediment control in cheir
planning area. A detailed discussion of their findings is presented in
reference 13.
*Numbers after titles refer to SCS Technical Guide publications.
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The BMP's for sediment control identified by SCS should be developed
on a field-by-field basis as conditions vary from site-to-site. Generalized
examples of BMP's include:
Leave native vegetation in the bottom of all drainages.
Minimize tillage.
Consult the Soil Conservation Service before breaking rangeland
and converting the crop production.
Leave a buffer strip along streams and reservoirs.
Construct check dams where economically feasible.
Fence range land to get more uniform use.
Additional management practices include:
Access Road (560-1)
Critical Planting Area (342)
Deferred Grazing (352)
Firebreak (382)
Grazing Land Mechanical Treatment
Holding Pond (425-1)
Livestock Exclusion (472)
Pasture and Hayland Management (510)
Pasture and Hayland Planting (512)
Planned Grazing System (556)
Proper Grazing Use (528)
Spring Development (574-1)
Stock Trails and Waterways (575)
Conservation land treatment and range management measures will control
erosion and reduce sediment yields. SCS has identified some land treatment
measures that may be used in the Sixth District planning area and associated
costs. This information is presented in Table 5-6. Proper range management
involves several practices.
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TABLE 5-6
LAND TREATMENT MEASURES AND COSTS, 1977 DATA
Conservation Land
Treatment Measures
Conservation Cropping System*
Contour Farming
Cover and Green Manure Crop
Critical Area Planting
Shaping
Cover Crop
Seed and Seeding
Mulching
Sodding
Crop Residue Use
Structures (40
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Irrigation
Irrigation is a major beneficial use of water within the Sixth District
planning area. Concentrated irrigation development is centered around three
areas: The Belle Fourche project, the Angostura project, and the Rapid
Valley. There are also thousands of acres of smaller irrigated areas.
The goal of the best management practices should be to control' salinity,
the leaching of nutrients, and sediment production, not eliminate them (13).
Management Practices
Chiseling and Subsoiling (324)
Conservation Cropping System (328)
Contour Farming (330-A)
Crop Residue Use (344-A)
Drainage Field Ditch (590-1)
Drainage Land Grading (462-1)
Drainage Main or Lateral (480-1)
Grassed Waterway or Outlet (412-A)
Grasses and Legumes in Rotation (411)
Irrigation Canal or Lateral (320-1)
Irrigation Ditch and Canal Lining (Concrete
and Pneumatically Applied Mortar) (358-A-l)
Irrigation Ditch and Canal Lining
(Flexible Membrane) (358-B-l)
Irrigation Ditch and Canal Lining
(Galvanized Steel (358-C-l)
Irrigation Field Ditch (388-1)
Irrigation Land Leveling (464-1)
Irrigation Pipeline (432-A-l, 432-B-l,
432-C-l, 432-D-l, 432-E-l)
Irrigation Pit (552-B-l)
Regulating Reservoir (552-B-l)
Irrigation Storage Reservoir (436-1)
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Management Practices
Irrigation System, Drip (441-1)
Irrigation System, Sprinkler (443-1)
Irrigation System, Tailwater Recovery (447-1)
Irrigation Water Management (449-1)
Minimum Tillage (478)
Mulching (484)
Straw Mulching (484-Supplement 1)
Regulating Water in Drainage Systems
Stripcropping (585-A, B, C)
Stubble Mulching (344-B)
Subsurface Drain (606-1)
Toxic Salt Reduction (610)
It must be pointed out that while an attempt has been made to segregate
BMP's by agricultural practices several of them are applicable to other
than the category listed. Furthermore, SCS has identified several other ~
management practices which can be applied to a broad range o£ activities
besides agriculture. These management strategies are listed below:
Management Practice
Clearning and Snagging (325-1)
Dam, Multi-purpose (349)
Debris Basin (350-1)
Dike (356-1)
Emergency Tillage (365)
Farmstead and Feedlot Windbreaks (380)
Floodwater Retarding Structure (402-1)
Floodway (404-1)
Grade Stabilization Structure (410)
Grassed Waterway or Outlet (Natural Watercourse (412-A)
Land Smoothing (466-1)
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Management Practices
Open Channel (582-1)
Pond Sealing or Lining (521-A-l, 521-3-1,
521-C-l, 521-D-l)
Pumping Plant for Water Control (533-1)
Range Seeding (550)
Recreation Area Improvement (562)
Recreation Area Stabilization (561-1)
Recreation Land Grading and Shaping (566-1)
Recreation Trail and Walkway (568-1)
Stream Channel Stabilization (584)
Streambank Protection (580-1)
Terrace, Basin (599-1)
Tree Planting (612)
Woodland Direct Seeding (652)
Woodland Improvement (666)
Woodland Pruning (660)
Woodland Site Preparation (490)
Construction Management Practices
Construction activities are capable of producing large quantities
of suspended solids and many other types of contaminants in receiving
waters. The quality and type of pollutants produced by construction
work depends on many factors. A partial list of these factors includes
the type and duration of the many construction practices
the size and location of the construction site relative to a
water course
the rainfall intensity and frequency
pest control measures
soil type
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relation of wind to the erosion potential of the soil
the number of construction workers needed for the work
the type and quantity of machines necessary for accomplishing
the task.
Local erosion control practices will play a significant role in the
quantity of pollutants discharged to the receiving water. It must be
emphasized that identification of the necessary management practices for
nonpoint source control should occur during the initial planning and
design of a project. Some of the problems which should be taken into
account include:
Groundwater contamination
Potential mudslide or landslide areas
Stream crossing structures
Landfills, culverts, dikes, and building encroachments
on surface waters
Increased stormwater runoff
Diversion and gradings that may change existing drainage patterns
Borrow pit construction
Removal of accumulated sediment
Stream channel modifications
Chemical water disposal
Dust and smoke control
Temporary road construction
Construction site location relative to water bodies
Construction of temporary water settling basins
The following is an inventory of nonpoint control management practices
for construction activities. This information has been edited from the
EPA report on "Process, Procedures, and Methods to Control Pollution
Resulting from All Construction Activity."
Construction Management Practices
Surface Roughening - This practice reduces the ability of moving
water to detach soil particles and transport them.
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Interception and Diversion Practices - These are practices designed
to intercept runoff before it has a chance to come in contact with an
erodible soil surface and to divert it to a safe disposal area.
Vegetative Stabilization - Vegetation is used both for temporary or
short-term stabilization and permanent or long-term stabilization.
Non-vegetative Soil Stabilization - As in the case of vegetative
soil stabilization, non-vegetative soil stabilization Includes both
temporary and permanent stabilization.
Vegetative Practices - The principal types of vegetative practices
include vegetative buffers and the soil inlet filter. Buffers are used
to detain, absorb, and filter overland runoff and thus remove sediment
from the water. They include natural vegetative buffers, installed
vegetative buffers, and contour strips or buffers.
Structural Control Practices - Sediment control structures include
filters, traps, basins and diversion structures. These practices vary
widely in cost, complexity, and effectiveness. Commonly used filters
include the gravel inlet filter and the filter berm. Both are constructed
out of coarse crushed stone or gravel and are usually only effective in
removing the coarser textured sediment.
Specialized Sediment Techniques - These refer to channel relocation
and water treatment.
Control of Pesticides, Nutrients, Solid Waste, Construction Chemicals,
Petroleum Products, Other Pollutants - The Sixth District Council has
identified several BMP's and their associated costs for their planning
area (13). These data are presented in Tables .5-7 and 5-3-.
Septic fank Systems
Septic tank systems of the 201 Study Area are evaluated in detail
in Appendix A of the -Draft EIS. Practices that are identified for controlling
these facilities: include:
Identify soil capabilities to assimilate wastewater and density
of units.
Proper design, installation, and maintenance.
Adhere to South Dakota septic tank regulations.
Pollution problems associated with septic tanks in the Study Area
are limited.
Silviculture (Forestry)
After agriculture, more land in the Sixth District planning area is
devoted to forest resources than to any other land use (13). This can
be seen by comparing the number of acres classified as Forest and Woodland
managed by the U. S. Forest Service (1,050,000 acres) plus that managed
privately (215,000 acres) to that within the project area. Approximately
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TABLE 5-7
ALTERNATIVE 8EST MANAGEMENT PRACTICES FOR
CONTROLLING CONSTRUCTION EROSION
Strategy
Management Practice
Reduction in
Sediment Yield
Cost per
Acre (1976)
I
Seed and fertil izer
362
5 S50
II
Chemical protection' for 12 months
44J
SI,300
III
Seed, fertilizer and chemical protection
for three months*
481
$1,350
IV
Seed, fertilizer and chemical protection
for 12 months*
621
$1,350
V
Seed, fertilizer and straw mulch
65:
51,250
VI
Seed, fertilizer and chemical protection
retention basin serving 100 percent of
for 12 months and a
the site*
sediment
90S
$1,550
VII
Seed, fertilizer, straw mulch and a sediment retention basin
100 percent of the site
serving
931
$1,450
Examples of chemical protection are the asphaltic and rubber emulsions.
Source: Oa1ton-Oa1ton-Llttle-Newport
TABLE 5-8
COST OATA FOR IMPLEMENTATION OF SOIL EROSION ANO SEDIMENTATION
CONTROL ALTERNATES
(1976 DOLLARS)
Trea Bient
Cost
Check dan, gravel and earth- 1' high x S' wide
2' high x 15' wide
Check dam, grouted rock riprap 2' high x S' wide
Check dan, concrete:
. 3" high x 10' wide
5' high x 20' wide
2' high x 5' wide * 4' long
S'6" high x 9'8" wide x S' long
/' high x 20' wide x 20' long
Olversion d1'
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11 percent of the land area within the Black Hills 208 Project is devoted
to Forests and Woodlands and an additional 4 percent is administered by
the U. S. Forest Service as national grassland. Best management practices
for silviculture are developed by the U. S. Forest Service in cooperation
with the South Dakota State Forester. Within the 201 Study Area timber
production is not occurring, however application of such BMP's with the
National Forest would serve to protect water in Spearfish Creek and Higgins
Gulch.
Mining
Historically, mining has had a severe impact on water quality;
western South Dakota has been no exception. Mineral extraction requires
the blasting, removal and milling of large volumes of material. The void
created receives and can concentrate runoff which may intercept ground-
water, or infiltrate into an aquifer. Milling wastes dumped in a flood-
plain, mine void, or on a hillside are subject to the weathering action
of rainfall and surface water. The sum of all these conditions, the
mingling of water with newly weathering minerals, presents a great poten-
tial for water pollution.
Management practices suggested in the Sixth District 208 report should
be applied in Lawrence County where applicable. No mining activities
are identified in the 201 Study Area.
NONPOINT SOURCE MANAGEMENT AGENCIES (13)
The following discussion summarizes the basic framework and parameters
for the implementation of the nonpoint source control plan recommended
in the Sixth District 208 Study.
The management system must be able to regulate the following nonpoint
source activities: agriculture, silviculture, mining, construction, residual
waste disposal, land and underground pollutant disposal, and hydrographic
modifications.
Management agencies must also have public representation and must
be existing institutions with existing legislation. The Conservation
Districts will assume lead roles for the implementation of nonpoint source
control measures.
The agencies recommended already have the required statutory authority
under existing laws. Several of the recommended agencies have a continuing
effort regarding water quality which should be stressed and continued. The
primary recommendations are listed below. Sixth District Council of Local
Governments:
1. Provide technical assistance to member units,of government
regarding water quality.
2. Coordinate and compile the annual revision of the 208 plan
with an advisory committee composed of the implementing
agencies and citizen members.
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3. Insure that the annual revision will be a locally developed plan
with public participation.
Municipalities:
1. Assist in the development of and assume the responsibility for
implementing the Erosion and Sediment Control Program in incor-
porating areas.
2. Establish a program for reducing pollutants in urban runoff
within the limits of existing legislation.
3. Adopt any ordinances, as pretreatment of industrial wastes,
required for compliance with related federal laws.
Counties:
1. Assist in the development of and assume the responsibility for
implementing the Erosion and Sediment Control Program regarding
non-agricultural activities.
2. Develop appropriate plans to provide for orderly growth and
minimize the impacts of development.
3. Enforcement of existing household wastewater disposal regulations.
Division of Conservation:
1. Assist the Conservation Districts.
2. Insure the proper reclamation of surface mining operations.
3. Prevent contamination of groundwater by exploratory drilling
and geophysical surveys.
Department of Game, Fish and Parks:
1. Review the actions of state and federal agencies relative to
their compatibility with the preservation of fisheries.
2. Continue the policy for the control of off-the-road vehicle
use with educational effort.
3. Develop an educational program for private forest owners on
erosion control.
Department of School and Public Lands:
1. Implement the practices recommended by the Conservation Districts
on school lands.
South Dakota Department of Water and Natural Resource
1. Prevent contamination of groundwater by oil and gas exploration
or production.
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2. Review proposed irrigation projects to determine their impact
on the quality of surface and groundwater.
3. Review and recommend to the Governor decisions on 208 Water
Quality Plans.
Soil Conservation Service:
1. Provide assistance to the Conservation Districts in the
implementation of the erosion and sediment control program
and the establishment of an education program.
2. Give priority to cost-sharing programs regarding water quality.
Agricultural Stabilization and Conservation Service:
1. Encourage the set-aside of areas sensitive to erosion.
2. Give high priority to cost-sharing practices that benefit the
people downstream as opposed to those practices primarily for
the benefit of the property owner.
3. Verify that cost-shared projects are properly maintained.
Cooperative Extension Service:
1. Provide more aggressive educational programs relating to all
aspects of water quality.
U. S. Forest Service:
1. Provide for the implementation of proper management practices
on U. S. Forest Service System lands.
2. Reclaim unnecessary roads and trails.
3. Develop and publicize wet season travel restrictions through
an educational program.
Bureau of Land Management:
1. Provide for the implementation of proper management practices
on Bureau of Land Management lands.
2. Incorporate the proper protective requirements into any permits,
leases, management plans, etc.
FLOQDPLAIN/HAZARD IDENTIFICATION
Introduction
Encroachment on floodplains, such as residential/commercial develop-
ment reduces the flood-carrying capacity and increased flood heights,
thus increasing flood hazards in areas beyond the encroachment itself.
One aspect of floodplain management involves balancing the economic gain
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from floodplain development against the resulting increase in flood
hazard. As human occupation of the land increases the flood damage
potential increases correspondingly. Two principal methods are commonly
employed to prevent or abate flood damages as follows:
The construction of dams and protective works to either impound
flood waters or to limit their flow within predetermined
boundaries.
The adoption of legal restrictions concerning the occupation
of flood hazard areas.
Of the two methods used to control floods, restricting occupation
in flood hazard areas is likely the more economical and effective solution
for the Spearfish area. Most flood damages occur in areas where the flood
hazard was or should have been readily apparent.
Identification of Floodplains
Definition
A floodplain can be described as an area adjacent to a stream, which
is subject to flooding as a result of the occurrence of an intermediate
regional flood and which is so adverse to past, current, or foreseeable
construction or land use as to constitute a significant hazard to public
health and safety or to property.
In an attempt to define the frequency of an intermediate regional
flood statistically, the terms 100-year flood or 1 percent flood are
commonly used. This does not specify the actual recurrence interval
between such floods but rather that on a statistical basis it can be
expected to occur once in a 100 year period. The best that can be said
is that these terms describe a type of flood for which reliable evidence
is available and which can be expected to reoccur at any time, but on
a rather infrequent basis. Whatever its frequency, the certainty of its
happening from time to time within the predicted time parameters is
sufficient to justify the adoption of prudent methods to prevent the loss
of human life and the destruction of property. An intermediate regional
flood falls far below the maximum possible flood, but considerably above
those lesser floods which usually occur during each spring thaw.
For purposes of the National Flood Insurance Program, the concept
of a floodway is used as a tool to assist local communities in this
aspect of floodplain management. Under this concept, the area of the 100-
year flood is divided into a floodway and a floodway fringe. The flood-
way is the channel of a stream, plus any adjacent floodplain areas, that
must be kept free of encroachment in order that the 100-year flood be
carried without substantial increases in flood heights. As minimum
standards, the Federal Insurance Administration limits such increases
in flood heights to 1.0 foot, provided that hazardous velocities are
not produced.
Delineation
There will never be any total agreement concerning the calculations
113
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which should be made to compute the amount of water at any given point
which constitutes an intermediate regional flood. However, there is
sufficient standardization in procedure to permit the reasonable identi-
fication of such a flood. For the purposes of Lawrence County, the
calculations should be based on the 100 year flood 'flow in Spearfish
Creek of 7,460 cfs as defined by the U. S. Army Corps of Engineers. The
overriding consideration is that the mapping must be in such sufficient
detail as to permit identification of the flood hazard area on the ground
itself._ The average cost of such mapping is currently about $3,000.00
per lineal mile. The total cost of detailed floodplain identification
is about $6,000.00 per lineal mile. These costs may be greater or lesser
depending upon the detail desired and the width of the area to be covered.
If Lawrence County can not fund, either directly or through grant
assistance, the necessary floodplain boundary mapping it could be
accomplished by the individual developer's engineer. Such a procedure
would require obtaining cross-sectional information, use the approved
flow, and calculation of the flood depth using open-channel hydraulic
formulas.
From any computed volume of water in a stream, its velocity and
territorial occupation can be predicted with considerable accuracy.
The obvious purpose of defining any probable flood is to make it possi-
ble to trace its path upon the ground. The end product of any floodplain
study must be a map of such adequate detail as to permit the ready
identification of the flood hazard area on the ground.
The scale of mapping may vary from area to area. In general, much
greater detail and smaller contour intervals are needed in urban and
developing areas than in rural or undeveloped areas. Each local govern-
mental agency must determine for itself the scale and other detail which
goes into the mapping program.
The delineation of the flood hazard area by adequate mapping and
accompanying data report constitute the finished product upon which land
use decisions should be based.
It cannot be over emphasized that floodplain delineations are valid
only as long as those conditions exist which existed at the time the
delineation was made. Natural changes in the carrying characteristics
of any stream can be predicted to some extent, but changes made by man
cannot be predicted. Severe changes in the configuration of any flood-
plain can be made by the placement of restrictive bridges or culverts,
by floodproofing measures, or by any other methods which alter either
the normal or flood channel of the stream.
FLOODPLAIN PRIORITIES
Lawrence County does not currently have the funds and trained
personnel to accomplish flood hazard identification for all streams.
Therefore, it is necessary to establish stream priorities to accomplish
flood boundary mapping. The following is a suggested criteria for
establishing the need for mapping priorities.
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Priority 1 - Areas proposed for immediate development.
The best and most obvious method of minimizing the flood hazard
threat is to restrict the occupation of flood hazard areas before such
occupation actually occurs. Immediate development is herein arbitrarily
defined as a period of within five years. The area contemplated for
development is one with little or no existing development. The area
is normally characterized by soaring land values and is under pressure
because of high density development in adjacent areas. Intense political
and economic counterpressure can be expected to be brought against efforts
to initiate land use controls.
In summary, the first priority describes a flood hazard area in which
human occupation can be expected to take place within a future period of
five years, unless some type of land use controls are accomplished.
Priority 2 - Areas already occupied.
This second priority defines those flood hazard areas which are already
occupied. While occupation is already an accomplished fact, some relief
can be obtained through floodproofing measures, by making flood insurance
available and by regulating future building.
Priority 3 - Areas of more future potential development
This third priority describes those flood hazard areas in which
potential development can be expected to occur at a time more distant
in the future than five years, unless land use controls are initiated.
LAND USE CONTROLS FOR FLOODPLAIN DEVELOPMENT
As indicated above the County does have the option, concurrently
to floodplain mapping, to implement land use controls. These controls
typically are in the form of building and zoning ordinances. The current
Floodplain District Ordinance is lacking since an accurate floodplain
boundary to establish a District is not available. A model ordinance
for floodplain management that would provide guidance and enforceability
once floodplain Districts are established was presented in Appendix C of
the Draft EIS.
Model Floodplain Ordinance
It is recognized that finalization and approval of a comprehensive
floodplain ordinance for Lawrence County will require time. It is also
recognized that local political and development pressures opposed to
land use controls can lengthen the process. The County does have the
interim option to continue and expand existing moratoriums on development
in alluvial areas. Such a position is likely to bring additional pressure
from pro-development interests. However, it must be emphasized that these
actions are oriented toward the protection of public health, safety, and
welfare. See Chapter L for the proposed EPA grant condition restricting
floodplain development.
115
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FLOODPLAIN MAPPING ASSISTANCE
The principal federal agency engaged in floodplain delineation is
the United States Corps of Engineers. In more recent years, the United
States Soil Conservation Service and the United States Geological Survey
have also engaged in floodplain studies and are expanding their activities
in this field. As a result of the establishment of a national flood
insurance program in 1968, the Federal Insurance Administration is also
engaged in flood hazard studies, although generally on a contractual basis.
While the above described federal agencies can be of great assistance
in delineating floodplains, there will always be a limit to the funding
available. In most" cases, the available federal funds can be supplemented
with state and local funds. It is the responsibility of the South Dakota
Division of Conservation to coordinate and establish priorities for all
floodplain studies involving either state or federal funds, or both.
The faster method of obtaining a floodplain study is for a local
jurisdiction to contract with a consulting firm using its own funds.
Under this procedure the study usually can be completed within less than
a year and does not require any prior approval or priority scheduling.
A disadvantage of this course is that it is the most expensive to the
local governments.
A considerable disadvantage of federal and state funding is the
required lead time for appropriations, generally at least a year. The
advantage is that it is considerably less expensive to the local government
involved. In such case, the local government would usually be providing
only twenty-five percent or less of the total cost.
116
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PUBLIC PARTICIPATION
AND COORDINATION
J
CHAPTER 6
$
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CHAPTER 6
PUBLIC PARTICIPATION AND COORDINATION
During the preparation of this document, meetings were held to inform
the public and solicit public comment. These meetings have involved the
pubTic at large, vested interest groups, and local and regional govern-
mental entities. At the outset of the project a citizens advisory commit-
tee was established and Roger Marshall, Northern Hills Sanitarian, was
designated as the committee leader. The committee met officially in
two public meetings and other informal meetings. The first public meeting
was held March 8, 1979 and discussed the scope of the project, identified
problems, public health risks, and wastewater treatment. The second
public meeting on November, 1979 discussed nonpoint source prohlems which are
contributing to the water quality problems, alternatives, and additional
data requirements.
At the final meeting of the advisory committee in November 1980,
those present voted unanimously to support the proposed EPA decision
to allow funding for the two proposed sewage interceptors. Further,
the advisory committee supported the no action alternative that interceptors
were unnecessary elsewhere at this time. EPA wishes to thank the members
of the advisory committee for their time and effort and is pleased to
accept and endorse their recommendations.
119
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LIST OF PREPARERS
CHAPTER 7
&
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CHAPTER 7
LIST OF PREPARERS
Environmental Protection Agency
Weston W. Wilson - Project Officer - Environmental Engineer
B.S. in Geological Engineering and M.S. in Water Resources Admin-
istration from the University of Arizona, Tucson, Arizona. Five
years experience with EPA as project officer for environmental
impact statements for wastewater treatment facilities including
Steamboat Springs, Colorado, and Jackson Hole, Wyoming. Special
emphasis has been on land application of effluent, investigation
of water rights, protection of environmentally sensitive areas
and federal-state-local government agreements. Preparation of
numerous EPA reports including water quality analyses, mined land
reclamation reviews, power plant sitings and dredge and fill
permits. Worked as EPA's consultant for the preparation of the
President's National Water Policy.
Engineering Science
Paul N. Seeley - Project Manager - Environmental Scientist
B.A. in environmental biology, University of Colorado. Six years
experience in water quality monitoring, water resource planning
environmental assessment, aquatic and terrestrial ecology,
evaluation of land application, and impact analysis for a variety
of wastewater treatment and disposal projects.
Doug Craig - Project Engineer
B.S. and M.S. in Engineering from Montana State University. Six
years experience in wastewater treatment and facility planning
and operations. Projects have included cost analysis, wastewater
treatment, wastewater facilities plans, and plant operations
consulting.
Allan L. Udin - Sanitary Engineer
B.S. and M.S. in Civil Engineering from Montana State University.
Fifteen years experience in water and wastewater treatment
facility planning, design, and operation. Projects have included
water treatment and storage facilities, water transmission lines,
water master plans, wastewater facilities plans, design of con-
ventional and advanced wastewater treatment facilities, and
plant operations consulting.
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REFERENCES
CHAPTER 8
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1,
2,
3,
4,
5,
6,
7
8.
9
10
11
12
13
14
15
16
CHAPTER 8
REFERENCES
Rahn, Perry H. and Arden D. Davis, Ground Water in Spearflsh Valley.
U.S Environmental Protection Agency. Denver, Colorado
July 31, 1979.
Brady Consultants, Inc. Wastewater Facilities Plan for Spearfish,
South Dakota. July, 1978
Personnel Communication. Steve Peters Lawrence County Planning and
Zoning Administrator.
U. S. Department of Commerce, Bureau of Census. County and City
Data Book. Washington, D. C. G.P.O. 1972.
South Dakota State Planning Bureau. Compositing-Natural Resources
and Land Use Information in Spearfish, South Dakota. A Land
Capability Study. 1979.
U.S. Soil Conservation Service. Unpublished Soil Survey of Lawrence
County.
Department of Environmental Protection. Administrative Rules of
South Dakota. Title 34, Article 34:04 Water Pollution Control
Program. Revised September 21, 1978.
U.S. Water Resources Council. Floodplain Management Guidelines
E.O. 11988. 43FR6030. February 10, 1978.
Federal Insurance Administration. Flood Insurance Study City of
Spearfish South Dakota Lawrence County. Preliminary March 29, 1979.
South Dakota Planning Bureau. Land Capability Maps, Computer
Generated. 1979.
Federal Insurance Administration. Flood Hazard Boundary Map.
Lawrence County, South Dakota. June 17, 1977.
Lawrence County. Zoning Ordinance Concerning Floodplain Districts.
Section 3.6.
Sixth District Council of Government. 208 Areawide Water Quality
Management Planning Program. Rapid City, South Dakota.
March 1978.
Harms, Leland, Urban Stormwater Management. Prepared for Sixth
District Council of Governments. No Date.
Brown, K. W., Wolf, H. W., Donnelly, K. C., and Slowly, J. F. The
Movement of Fecal Coliforms and Coliphages Below Septic Lines.
Journal of Environmental Quality. Volume 8, Number 1, 1979.
Denver Urban Drainage District. Model Floodplain Ordinance is
presented as a general guide for floodplain planning. Specific
communities needs will dictate inclusion of specific sections.
127
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INDEX
CHAPTER 9
a:<
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CHAPTER 9
INDEX
Archaeology - 60, 66
Belle Fourche, City of - 1, 9, 10, 18, 21, 30, 38, 48
Belle Fourche Water Supply 6, 14, 17, 18, 30, 47, 69, 100
Brady Engineers - 17
Brookview - 18
Chris' Campground - 5, 6, 25, 79, 89, 90, 91
Christensen Drive - 1, 5, 6, 7, 9, 13, 18, 25, 35, 36, 41, 46, 47, 56, 66, 79,
82, 83, 84, 96
Citizen's Advisory Committee - 30, 119
Costs/Funding - 7, 18, 22, 25, 31, 65, 67, 68, 69, 70, 73, 74, 75, 77, 78, 81,
83, 85, 92, 93, 94, 95, 96, 98, 99, 108, 119
DeBerg - 22, 37, 41, 43
Deer Meadows - 22, 37, 41
Drinking Water Pollution - 14, 30, 48, 67
Evapotranspiration System - 4, 6, 17, 31, 56, 68, 72, 73, 74, 76, 77, 78, 80,
81, 82, 84, 85
Farmers Home Administration - 94, 95, 97
Fecal Coliform - 5, 47, 49
Flood Hazard - 30, 42, 43, 44, 45, 46, 57, 59, 60, 67, 68, 69, 112, 113,
114, 115
Floodplains - 8, 9, 14, 30, 57, 59, 60, 110, 112, 113, 114, 115, 116
Fuller - 22, 37, 41, 44
Geology - 6, 13, 38
Grandview Acres - 22, 37, 41, 44
Grant Conditions - 7, 8, 9, 60
Groundwater Pollution - 1, 5, 6, 13, 14, 17, 18, 22, 25, 30, 48, 56, 60, 75,
79, 97, 107
Hardy - 22, 37, 41, 42
Higgins Gulch - 1, 4, 5, 6, 9, 13, 14, 18, 22, 30, 31, 35, 36, 37, 38, 41, 42,
43, 46, 47, 48, 49, 56, 57, 66, 71, 74, 75, 76, 77, 100, 110
Historical/Cultural Resources - 60, 61, 66
Holding Tanks - 6, 17, 68, 100
Hope Weiss Development - 13, 18, 31, 36, 37, 41, 42, 48
Hubbard - 18
131
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Infiltration Gallery - 1, 4, 5, 6, 9, 10, 38, 47, 48, 49, 56, 66, 67,
68, 71
Interceptors - 1, 6, 7, 8, 13, 14, 17, 18, 22, 25, 30, 31, 61, 69, 70, 74,
75, 76, 77, 78, 80, 81, 82, 84, 85, 94, 96, 97, 119
Lawrence County - 9, 30, 35, 41, 56, 57, 59, 60, 98, 110, 114, 115
Leach Fields - 4, 5, 7, 14, 17, 30, 31, 42, 43, 44, 45, 46, 48, 56, 67, 68, 71,
74, 75, 78, 79, 86, 87, 88, 89, 90, 91
MacKaben No. 1-22, 37, 41, 43
MacKaben No. 2-22, 37, 41, 43
McGuigan Farm - 61
Miller Ranch - 5, 25, 56
Minnekahta Formation - 25, 38, 39, 41
Mountain Plains - 1, 7, 13, 18, 22, 35, 36, 38, 41, 45, 56, 66, 75, 78, 79, 80
Mountain View - 25
National Flood Insurance Program - 8, 9, 59, 113
No Action Alternative - 5, 6, 25, 67, 68, 71, 72, 73, 74, 75, 76, 77, 79, 80,
81, 82, 83, 84, 85, 119
Nonpoint Sources - 5, 6, 9, 30, 56, 66, 71, 76, 97, 98, 99, 101, 107, 110, 119
Northern Hills Sanitarian - 7, 30, 31, 56, 78, 119
Old Tinton Road - 22, 37, 41, 45
On-Site Systems - 4, 22, 25, 31, 35, 37, 38, 48, 56, 69, 78, 82
Pressure Effluent System - 70
Pressure Interceptor - 18, 31, 69, 72, 73
Scott Engineers - 17, 31, 72, 77, 81, 85, 86
Septic Tanks - 1, 4, 5, 6, 7, 9, 14, 17, 18, 22, 25, 30, 31, 39, 42, 43, 44,
45, 46, 48, 56, 60, 67, 68, 69, 70, 71, 74, 75, 78, 79, 82,
83, 97, 108
Soils - 4, 5, 6, 31, 39, 41, 42, 43, 44, 45, 46, 48, 56, 71, 74, 75, 79
South Dakota Department of Environmental Protection - 13, 47
South Dakota Department of Water and Natural Resources 7, 10, 14, 30, 31, 47,
68, 94, 111
South Dakota Septic System Regulations - 5, 6, 7, 9, 31, 56, 68, 71, 74, 75,
78, 82, 108
Spearfish, City of - 1, 4, 5, 7, 9, 13, 14, 17, 18, 22, 25, 30, 31, 35, 37,
38, 42, 45, 46, 57, 59, 60, 96, 97, 98, 99
Spearfish Creek - 1, 4, 5, 6, 7, 14, 25, 38, 46, 47, 48, 49, 56, 57, 59, 60,
110, 114
Spearfish Creek Alluvial Valley - 6, 18, 25, 30, 35, 36, 41, 42, 47, 48, 49,
56, 66, 67, 68, 69, 70, 71, 72
132
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Spearfish Valley Sanitation District -1,9, 13, 14, 17, 30, 35, 36, 60, 96, 97
Spring Creek - 13, 14
State Historical Preservation Officer - 61
Surface Water Pollution - 1, 5, 6, 9, 13, 14, 30, 56, 97
U.S. Army Corps of Engineers - 57, 59, 114, 116
U.S. Department of Housing and Urban Development - 8, 59, 96, 97
U.S. Environmental Protection Agency - 1, 6, 7, 8, 9, 10, 13, 14, 47, 49,
60, 66, 67, 75, 78, 94, 97, 99, 107, 119
U.S. Geological Survey - 47, 116
U.S. Soil Conservation Service - 4, 41, 43, 46, 48, 57, 100, 101, 102, 103, 105,
112, 116
201 Wastewater Facilities Plan - 1, 6, 13, 17, 18, 22, 25, 30, 60, 65, 68, 74, 83
Westfield - 22, 37, 41, 45, 71
West Development - 5, 6, 7, 9, 13, 18, 36, 41, 42, 48, 56, 67, 96
133
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COMMENTS a RESPONSES
APPENDIX A
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DEPARTMENT OF THE ARMY
Omaha OikTAiCT C04PS O* INoiNllMS
*014 U S POST OFFICE AND COURTHOUSE
Omaha NIBRASK4 S0IO1
24 November 1980
Mr Ueaton W Uilion, Project Officer
U.S Environmental Protection Agency
Begion VIII
1860 Lincoln Street
Denver, CO 80295
Dear Hr Wilson
We have reviewed the Draft Environmental Impact Statement concerned with eewerage
needs m Lawrence County near Spearfish, South Dakota
Baaed on the information in this office,Higgina Creek has an average annual
flow of leas than 5 cubic feet per second Accordingly, activities on Uiggins
Creek for the purposes of Section 404 are authorised under the Nationwide
permit without further processing provided the following conditions are adhered
to
a. That the fill will not destroy a threatened or endangered species as
identified under the Endangered Species Act, or endanger the critical habitat
of such species,
b That the fill will consist of suitable material free from toxic
pollutants in other than trace quantities,
c. That the fill created by the discharge will be properly maintained
to prevent eroaion and other non-point sources of pollution, and
d. That the fill will not occur in a component of the National Wild and
Scenic Biver System or in a component of a State Wild and Scenic River System
In addition to the conditions specified above, the following management practices
should be followed to the maximum extent practicable in the performance of the
work
a Pills in spawning areas during spawning seasons should be avoided
b If the fill creates an impoundment of water, adverse impacta on the
aquatic aystem caused by the accelerated passage of water and/or the restriction
of its flow should be minimised
RESPONSE: 1. Acknowledge
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MHOPD-A
Mr Weston W Wilson
24 November 1980
c Filla in wetlands sress should be avoided
d. Heavy equipment working in wetlands should be plsced on oats.
e. Fills into breeding and nesting areas for migratory waterfowl should
be avoided
f All temporary fills should be removed in their entirety
g. Discharge of dredged or fill material into waters of the United States
should be avoided or minimized through the use of other practical alternatives
Spearfish Creek hag an average annual flow greater than 5 cubic feet per second,
thus, an individual or Natioowide permit will be required for activities on
this waterway. The method of construction for the crossing of this waterway
is not discussed in the statement. Accordingly, the City of Spearfish should
contact this office with a design of the crossing for review pursuant to
Section 404.
Page 64 states that Cultural Resources are not currently of concern based on
survey data. It is important in a Federally-funded project that the State
Historic Preservation Officer indicate in writing that such is the case
We will anticipate further correspondence from you and if you have any questions
concerning our consents pleaae call this office
Sincerely.
AftVltl L THOMSEN
Acting Chief, Planning Division
2
2. Facilities that may be built aB part of this action
will not cross Spearfish Creek. Therefore, no further
action ahould be necessary. Should the City of Spear-
fish, tbe Sanitation District, or Lawrence County
undertake action Independent of the proposed projects
which would cross Spearfish Creek, then they would be
required to comply with Section 404.
3. Neither the Chrlstensen Drive nor the West Subdivision
interceptor will be built in the vicinity of any known
historic site. The no action alternative is recommended
for the area of the McGulgan farmstead and the fish
hatchery, the only known historic sites that could poten-
tially have been directly affected by any of the proposed
alternatives. The EPA urges Lawrence County and local
officials to consider the impacts to historic sites of
any new development In the Spearfish area, and to work
with the State Historic Preservation Officer to mitigate
any impacts to historic sites that may result from
future growth.
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IS tUPLV RLfCJt TO
L7621 (RMR)PC
United Stales Department of the Interior
NATIONAL PARK SERVICE
ROCKY MOUNTAIN KlCIO\AL Ot-tlCb
UU p«rf«i Mrr«i
PO Boi 25^87
Denver Colorado
nrr 2 41S8T
Mr. Roger L Williams
Regional Administrator
United States Environmental Protection Agency
1860 Lincoln Street
Denver. Colorado 8029S
Dear Mr. Williams.
The National Park Service has reviewed the draft environmental Impact
statement for the Spearflah Sewerage Needs, Lawrence County* South
Dakota.
The various alternatives for wastewater management In areas outlying
the city of Spearflah will have no direct effecta on any units of the
National Park System. Thus, we offer no consents.
Sincerely yours.
Richard A Strait
Associate Regional Director
Planning and Resource Preservation
RESPONSE
Acknowledge
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STATE PLANNING BUREAU
State Capitol
Pierre South Dakota 57501
605/773-3661
Olllc* of
Executive fnonoQement
No venter 24, 1980
Roger L. Williams
Regional Administrator
U S Environmental Protection Agency
1860 Lincoln Street
Denver, Colorado 80295
RE EIS-040281
EPA 908/5-80-002A
Draft Environmental Impact Statement - Spearfish Sewerage Needs
>
I Dear Mr Williams
The State Clearinghouse has distributed for review the above stated draft
environmental impact statement. No comnents were received in regard to
this document, but thank you for the opportunity to review and conment
Sincerely,
James R. Richardson
Comai ssioner
STATE PLANNING BUREAU
JRR kah
RESPONSE: Acknowledge
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DEPARTMENT Of HOUSING AND URBAN DEVELOPMENT
REGIONAL/AREA Of F ICE
EXECUTIVE TOWER 1406 CURTIS STREET
DENVER COLORADO 80303
November 20, 1980
REGION VIII in »c»
8S0Q
Mr. Weston V. Wilson
Project Officer
U.S. Environmental Protection Agency
I860 Lincoln Street
Denver, Colorado 80295
Dear Hr. Ullaon
Thank you for the opportunity to review and comment on the draft
Environmental Impact Statement (E1S) ot the Spearflsh Sewerage
Needs In Lawrence County near Spearflsh, South Dakota.
Your draft haa been reviewed with specific consideration for the
areas of responsibility assigned to the Department of Housing
and Urban Development (HUD). Ue considered the proposals* compat-
ibility with local awl regional comprehensive planning and in pacts
J> on urbanized areas. Within these parameters, we find this document
1 Inadequate.
Ui
The "no option" alternative coupled with a prohibition on additional
pollution would cause a moratorium on new housing, therefore, any
action by CPA to fund a sewage Interceptor would clearly create a
condition to allow growth. The Impacts of this planned growth
should be evaluated In the Environmental Consequences section of
this EIS as directed by 40 CFR Part 1502.16(b) Potential Impacts
of this growth include those on the identified cultural resources
and on the existing public facilities. Noise levels will Increase,
urban aprawl could occur, and there could be a potential for Inef-
ficient energy use If this growth does occur. In addition, the
State Implementation Plan should include this potential growth in
relationship to Sectloo 176(c) of the Clear Air Act.
AREA OF! ICE
Umw Cotwsdc
Secondary growth Impacts were taken into consideration
and did affect the final selection of preferred alter-
natives. For example, piping sizes which would carry
curreot wastewater loads but which would accoonttdate
little new growth were selected for areas to be sewered,
and only two areas with proven wastewater pollution
problems will be sewered. Levels of noise, urban sprawl
inefficient energy use, and air degradation are not ex-
pected to increase significantly because of this project
EPA has conducted an analysis under Section 176(c) and
concludes that for thla area which is an attainment area
(no violations of ambient air quality standards), the
limited affect upon growth 1b consistent with the
approved state implementation plan.
-------
The EIS indicates that 25 percent of the coat of thla project
nay be funded by the city of Spearflsh through HUD's Community
Development Block Grant program (page 94) If this la the case,
the City should have been Invited to participate In thla EIS as
a Cooperating Agency (24 CFR Part 1501.6).
If you have any questions regarding these comments, please contact
Mr. Carroll F. Goodwin, Area Environmental Officer at 837-3102.
Sincerely,
fond D. Mc Kinney
Director
Program Planning and Evaluation
2. Aa the grantee of the 201 planning funds the City of
Spearflsh has participated in the EIS proceas.
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3®
United Slates Department ol the Interior
FISH AND WILDLIFE SERVICE
AREA OFFICE. SOUTH DAKOTA —NEBRASKA ^
post orncx BOX 110 Ij > I
PIERRC. SOLTTH DAKOTA 57501
ZS&O-L
November 24, 1980
>
Mr. Roger L. Williams
Regional Administrator
U.S. Environmental Protection Agency
Region VIII, 1860 Lincoln Street
Denver, Colorado 80295
Dear Hr. Hill lams.
DEC , Y 1980
I
tPA REGI
Vtoltf Divuiun
We have reviewed the Draft Environmental Impact Statement (DEIS).
Spearflsh Sewerage Needs, Lawrence County near Spearflsh, South Dakota
(EPA-908/5-80-002A), and are providing the following cotrments In accord-
ance with Section 102(c) of the National Environmental Policy Act.
These comments represent the views of the U S Fish and Wildlife Service
only and do not constitute review of the project by the Department of
the Interior.
The stated purpose of the DEIS Is to present an evaluation of all the
alternatives considered to accomplish wastewater management for areas
outlying Spearflsh. The DEIS Identifies four main areas that have
potential for contributing to pollution of ground and surface water, and
In particular, the Belle Fourche Infiltration gallery. These four sites
are Spearflsh Creek Alluvial Valley, Upper Hlgglns Gulch, Mountain
Plains and Chrlstensen Drive developments.
After reviewing the DEIS, we concur with EPA's conclusions regarding the
alternatives selected for three of the areas The alternatives that
were recommended are (1) a 3,600-foot, 8-1nch gravity sewer line for
Chrlstensen Drive, (2) a 4,000-foot, 8-Inch sewer line and a 2,050-foot
force main and Dump station to the West Subdivision In Lower Spearflsh
Valley, and, (3) the utilization of septic tank systems In the Upper
Hlgglns Gulch Area (no-action alternative). We do not agree with the
no-action alternative for the Mountain Plains Subdivision which would
utilize septic tank systems for wastewater management.
•. fzA
t*A
8Mb
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2
>
I
00
We have reached this decision regarding the Mountain Plains Subdivision
based on several of the statements presented In the DEIS regarding the
geology and soil conditions present at the Mountain Plains site, the
status of the Spearflsh National Fish Hatchery on the National Register
of Historic Places, and concern about the effects of potential water
quality degradation on hatchery operations and production The Fishery
Center 1s a National Fish Hatchery operated by the U.S. F1sh and Wild-
I life Service On page 7 of the DEIS, 1t Is stated that while water
quality and wastewater treatment Is not presently a demonstrated problem
at Mountain Plains Subdivision, future problems could develop If waste-
I water management Is not closely monitored. It Is stated on page 20 that
there are only 10 homes currently on Individual disposal systems with 62
additional lots ready for development and an additional 600 acres ready
j| to be plotted Of the recently constructed homes, there has already
I been one failure of a sewage system The DEIS states that the county
| has limited capacity to Insure system manageability and reliability, so
I more failures will probably occur.
It Is further stated in the DEIS, on pages 23 and 37, that the Mountain
Plains Subdivision lies on the Mlnnekahta Limestone formation and that
seepage from Individual wastewater treatment Into underlying groundwater
may occur because the limestone 1s severely fractured The statement
clearly indicates that effluent from the septic systems could reach the
surface waters of Spearflsh Creek due to fractures In the limestone
The Mlnnekahta formation is described as a laminated limestone (meaning
split into layers) with solution caverns and sinks, all of which He
above Spearflsh Creek and the Spearflsh National Fish Hatchery. The
soils overlying the Mountain Plains Subdivision are discussed on page 44
Indicating that the area Is unsulted for septic tank systems The Soil
Conservation Service recommended that septic tank systems should be
built only on the lower portions of the landscape where slopes are less
steep The Mountain Plains Subdivision, however, covers the upper
slopes of the area. It is further stated on page 54 that, "The Mountain
Plains area does have a high potential risk of contaminating groundwater
aquifers 1f conventional septic systems are used to dispose of waste-
water as development density Increases."
The Spearflsh National Fish Hatchery Is located in the lower end of Fish
Hatchery Gulch. It is an operational fish hatchery, raising trout for
release In Black Hills' streams and other streams and reservoirs In the
Upper Missouri Basin. The Spearflsh National Fish Hatchery is one of
the oldest hatcheries In the United States, having been constructed in
1899. Its original water source was interrupted In the 1930's by
mining operations at the Homestake Gold Mine, and the hatchery now has
to rely on water supplied directly from Spearflsh Creek and shallow
I wells which tap aquifers underlying the Mlnnekahta formation Water
quality In Spearflsh Creek is presently sufficient to maintain operations.
Water quality and wastewater treatment currently are not
problems, and will not develop Into problems If good
wastewater management practices are Implemented by Uv-
rence County. The South Dakota State eeptlc system
regulations are sufficiently thorough and will protect
water quality provided tbcy are strictly enforced In the
Mountain Plains area as well as throughout the entire
201 Study Area. On pages 7, 6, and 106 of the E1S the
EPA reconanends local officials require strict adherence to
the state septic system code.
A total of 191 lots occur in Mountain Plains To date,
only ten have been developed. Providing an interceptor
to the subdivision could promote development of the re-
maining lots with sttendant secondary Impacts, including
increased nonpoint source degredatlon of water quality
No sewage system failures have occurred In Mountain Plains.
One houaeovner Installed a system in violation of state
septic system regulations, and will be required to replace
It with a system which is In compliance with the current
regulations EPA Is waiting confirmation that this
correction has occurred.
System manageability and reliability is limited only because
of a lack of enforcement of state septic systems regulations.
If state regulations are enforced, as recommended by EPA,
manageability and reliability of on-site disposal systems
In Mountain Plains should be high.
Acknowledge
Strict adherence to the state septic system regulations will
allow conventional septic systems (septic tank-leach field
systems) to be Installed only in areas where adequate soil
treatment of wastewater will occur. Non-conventional or
engineered septic systems, including mound systems and
evapotransplratlon systems, will provide adequate treatment
in some areas unsulted for conventional systems and if
properly designed and Installed are deemed acceptable in
such areas, as noted in page 6 of the EIS. Other areas may
be unsulted for soli treatment of wastewater, and under
strictly enforced state regulations no such system may be built
in such areas
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3
however. If, as the DEIS states, there could be high potential for
septic system failure to contaminate Spearflsh Creek and groundwater
aquifers, then the hatchery would not be capable of continuing oper-
ations
It Is the opinion of the U.S. Fish and Wildlife Service that the status
of the Spearflsh National Fish Hatchery as a viable fish hatchery Is
threatened by the use of septic systems to provide wastewater management
for the Mountain Plains Subdivision. He also believe that the status of
the hatchery on the National Register of Historic Places is threatened
In that ft is now a functional hatchery, but If 1t loses Its current
supply of high quality water, hatchery operations as they now exist
would be severely affected. Because of the Indication that contami-
nation from septic effluent has a high probability of occurrence and the
fact that it would likely not be detected until Spearflsh Creek and the
underlying aquifer are contaminated, hatchery operations would not be
easily restored by after-the-fact remedial measures. This 1s 1n con-
tradiction to the statement on page 59 that asserts that none of the
National Register sites located within the project area would be affected
by any of the proposed alternatives.
We therefore recomnend that CPA reconsider Its decision 1n regard to the
no-action alternative for the Mountain Plains Subdivision In favor of
the 6rav1ty Collection/Interceptor System. The Gravity Collection/
Interceptor System would have high reliability, would be moderately
flexible to accommodate expansion, would achieve the water quality goals
of the area (the no-action alternative will not achieve water quality
goals), and has good system manageability (the no-action alternative
does not).
We appreciate the opportunity to review the Oraft CIS and hope that our
concerns for the Spearflsh National F1sh Hatchery can be allayed If
you have any questions concerning our comments, please contact Tom
O'Brien at 605/224-8692 or FTS 782-5226.
cc: ENV, Denver, CO
HCRS, Denver, CO
SDDGFP, Pierre, SO
SDOWNR; Pierre, SO
SO Historical Survey,
Vermillion, SO
Sincerely yours,
\ ipnes W Salyer &
*rea Manager
Over ninety percent of the water used In the Spearflsh
National Flab Hatchery la from Spearflsh Creek. The following
risk assessment was conducted to estimate the effects on
Spearflsh Creek water quality of a total failure of all
on-site wastewater disposal systems in the Mountain Plains area
at two levels of development, the twenty-year projected
population of 280 people, and a total buLldout population of
646 people.
Assumptions used In this exercise are as follows
- Wastewater generation of 100 gallons per person per day
- Lowest expected 24-hour flow In Spearflsh Creek: 9 cfs (this
la the lowest 24-hour flow recorded In the creek over a
14-year period. Average flow is 51.3 cfe)
- Concentration of pollutants In raw wastewater (Source:
Metcalf and Eddy, Wastewater Engineering. Treatment,
Disposal, and Reuse 1979)
Chloride - 50 mg/1
Phosphorus - 8 mg/1
Ammonia nitrogen - 25 mg/1
Nitrate nitrogen — 10 mg/1
- Current concentration of pollutants in Spearflsh Creek
(Source: EPA STORET).
Chlorides - 3.54 mg/1
Phosphorus (Ortho as P) 0 015 mg/1
Ammonia nitrogen 0.021 mg/1
Nitrate plus nitrite nitrogen 0 50 mg/1
- One hundred percent of the wsatewater flows directly into
Spearflsh Creek. No evaporation or ground absorption and
treatment occurs; no wastewater runs off into any other
drainage.
Using the mass balance equation. Parameter Concentration
Instream •
(Flow 1)(Parameter Cone l)+(Flow 2)(Parameter Cone 2)
Flow 1 + Flow 2
the values in Table 1 were generated. As shown in the
table, total failure of all on-site wastewater disposal
systems for the projected 20-year population of 280 at the
lowest expected flow In Spearflsh Creek will not exceed any
atate standards or federal recouraendatlons for water quality
In Spearflsh Creek. Total failure for a total bulldout
population of 646 people will exceed federal recommendations
for phosphorus, and stste standards for un-ionlzed ammonia
in Spearflsh Creek.
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TABLE 1
INSTREAM CONCENTRATIONS OF POLLUTANTS FROM TOTAL FAILURE
OF ALL ON-SITE DISPOSAL SYSTEMS IN MOUNTAIN PLAINS
Chlorides
Phosphorus
Ammonia^
Nitrogen
Un-loniied^
Ammonia
State
Standards/
Federal
Recommends-
tlon
100 mg/l2
0.1 mg/l
0.02 mg/l
10 mg/l1
20 Year
Population
Projection
(280 people)
3 8 mg/l
0.059 mg/l
0.159 mg/l
<0.02 mg/l
0 56 og/1
Total
Bulldout
(646 people)
4.1 mg/l
0.103 mg/l*
0 295 mg/l
>0.02 og/1*
0 60 og/1
1. Water supply use designation standard
2. Cold water fishery use designation standard
3 Maximum concentration of NH. yielding un-lonlzed
ammonia value of leas than 0.02 mg/l at worst case
temperature (14 C) and pH(8.6) recorded in Spearflsh
Creek is 0.224 mg/l.
* Will exceed standard or recommendation at worst case
flows, temperatures, and pH's
Some uotreated wastewater from failed septic systems In Moun-
tain Plains would probably flow Into Spearflsh Creek via
Fish Hatchery Gulch. Concern was expressed that wastewater
in Fish Hatchery Culch could flow into the fish hatchery
The existing drainage channel could probably divert waste-
water away from the hatchery except under extreme flood condi-
tions. Enlarging the drainage channel would probably mitigate
against contamination of the hatchery ponds during any flood
conditions.
The EPA appreciates the U.S. Fish and Wildlife's concern
about water quality in the Mountain Plains area However,
the EPA feels that strict compliance with state septic system
regulations will adequately protect surface and ground water
quality.
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United States Department of the Interior
OFFICE OF THE SECRETARY
WASHINGTON, D C 20240
OtC 2 2 198Q
ER 60/1438
Mr. Boger L. Williams
Beglonal Admlnlst xator, Regloo VIII
Environmental Protection Agency
1660 Lincoln St net
Denver, Colorado 80295
Dear Mr. Wllllamss
By public notice, dated October 17, 1980, views and comenta vets
requested on a draft environmental Impact statement on the Spearflsh
Sewerage Needs, Lawrence County near Spearflsh, South Dakota. Copies
of the notice and draft statements weta not received In this office
until December 2, 1980, one day after the fbmal comment period was
concluded.
This Department does wish to provide input Into this Impact statement
from the standpoint of Its Jurisdiction and/or special expertise.
Accozdlngly, we tequeat an extension of time until mid-January to
provide you with our comments.
Sincerely,
xuce Blanche xd
Director
Envl nnimental P reject Review
1. Comment period was extended to accommodate this requeut
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United States Department of the Interior
BuiMTrr 67, Room 688
Denver Federal Center
Dcjutfr, Colorado 80225
ER 80/1438
January 13, 1981
Mr. Roger L Williams
Regional Administrator, Region VIII
Environmental Protection Agency
1860 Lincoln Street
Denver. Colorado 80295
Dear Mr. Williams:
We have reviewed the Draft Environmental Impact Statement (DEIS) for Spearflsh
Sewerage Needs, Lawrence County, South Dakota, and have the following comnents.
The stated purpose of the DEIS Is to present an evaluation of all the alternatives
considered to accomplish wastewater management for areas outlying Spearfish.
The DEIS identifies four main areas that have potential for contributing to
pollution of ground and surface water and. In particular, the Belle Fourche
Infiltration gallery. These four sites are Spearflsh Creek Alluvial Valley,
Upper Hlggins Gulch, Mountain Plains, and Christensen Drive developments.
After reviewing the DEIS, we concur with Environmental Protection Agency's (EPA)
conclusions regarding the alternatives selected for three of the areas These
alternatives are. (1) a 3,800-foot, 8-Inch gravity sewer line for Christensen
Drive, (2) a 4,000-foot, 8-inch sewer line, and a 2,050-foot force main and pump
station to the West Subdivision in Lower Spearflsh Valley, and (3) the utilization
of septic tank systems In the Upper Higgins Gulch Area (no-act1on alternative).
We do not agree with the no-action alternative for the Mountain Plains Subdivision
which M)uld utilize septic tank systems for wastewater management.
We have reached this decision regarding the Mountain Plains Subdivision based on
several of the statements presented in the DEIS regarding the geology and soil
1 conditions present at the Hountain Plains site, the status of the Spearfish
National Fish Hatchery on the National Register of Historic Places, and concern
about the effects of potential water quality degradation on hatchery operations
and production. The Fishery Center Is a National Fish Hatchery operated by the
U S Fish and Wildlife Service and 1s one of the oldest hatcheries In the
United States, having been built In 1899. On page 7 of the DEIS, it is stated
that while water quality and wastewater treatment Is not presently a demonstrated
problem at Mountain Plains Subdivision, future problems could develop If wastewater
management is not closely monitored. It 1s stated on page 20 that there are
only 10 homes currently on individual disposal systems with 62 additional lots
RESPONSE Water quality effects ot the no action alternative In
Hountain Plains to Spearflsh Creek and the Spearflsh National
Fish Hatchery are addressed In response to a letter from
the U.S. Fish and Wildlife Service (pages A-7 through A-10).
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ready for development and an additional 600 acres ready to be plotted. Of the
recently constructed hornet, there has already been one failure of a sewage
system. The DEIS states that the county has limited capacity to ensure system
manageability and reliability, so more failures will probably occur.
It is further stated In the DEIS, on pages 23 and 37, that the Mountain Plains
Subdivision lies on the Hinnekahta Limestone formation and that seepage from
individual wastewater treatment systems into underlying groundwater may occur
because the limestone Is severely fractured. The statement Indicates that
effluent from the septic systems could reach the surface waters of Spearfish
Creek due to these fractures in the limestone The Hinnekahta formation is
described as a laminated limestone with solution caverns and sinks, all of which
lie above Spearfish Creek and the Spearfish National Fish Hatchery.
As discussed on page 44, the soils underlying the Mountain Plains Subdivision
seem to be unsuitable for septic tank systems. The Soil Conservation Service
recommended that septic tank systems should be built only on the lower portions
of the landscape where slopes are less steep. It is further stated on page 54
that the Mountain Plains area does have a high potential risk of contaminating
groundwater aquifers if conventional septic systems are used to dispose of
wastewater as development density Increases
The status of the Spearfish National Fish Hatchery, as a viable fish production
center, is threatened by the use of septic systems to provide wastewater management
for the Mountain Plains Subdivision. The document indicates that contamination
from septic effluent has a high probability of occurrence and would likely not
be detected until Spearfish Creek and the underlying aquifer are contaminated
Hatchery operations would not be easily restored by after-the-fact remedial
measures. This is in contradiction to the statement on page 59 that asserts
that none of the National Register sites located within the project area would
be affected by any of the proposed alternatives
We therefore recoamend that EPA reconsider its decision regarding the no-action
alternative for the Mountain Plains Subdivision in favor of the Gravity Collection/
Interceptor System The Gravity Collection/Interceptor System would have high
reliability, would be moderately flexible to accomodate expansion, and would
achieve water quality goals for the area (the no-action alternative does not).
Mineral Resources
Within the boundaries of the 201 study area that surrounds the town of Spearfish
(illustrated on Figures 1-1 and 1-2 1n the document), known mineral deposits
include gypsum, calcium, sand and gravel, stone, and talc (variously located in
Sections 10, 16, and 27. T 6 N. R 2 E. and Section 28, T 7 N. R 2 E). according
to Bureau of Mines records.
The records, however, are neither complete nor up to date enough for us to Judge
if any or all ftf these deposits are now being worked, arid If they are. how
severely the operators will be affected by the proposed sewer connections and
improvements. Active or potentially active mineral conmodlty producers should
be given the necessary opportunity to continue operations or to relocate nearby
Sincerely,
Robert F. Stewart
Regional Environmental Officer
Because proposed pipeline alignments are vlthin existing
highway rights-of-way, the project would not preclude
nor adversely affect development of mineral resources.
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CITY Of fi£LL£ fOUflCUL\m fourche, south dahqia
November 26, 198ft
CERTIFIED MAIL
RETURN RECEIPT REQUESTED
Mr. Roger L Williams
Region 8 Administrator
United States Environmental
Protection Agency
1860 Lincoln Street
Denver. Colorado 80295
Tiff (c:
IIPA REr'
Vb\er u intuit
Re Comment on Draft Environ*
mental Impact Statement*
Spearfish sewerage needs
in Lawrence County near
Spearfish. South Dakota
. Dear Mr. Williams
>
(L, The City of Belle Fourche strongly objects to the
4> use of any type of individual subsurface sewage disposal
system (including mound type systems) in the water shed area
of the Belle Fourche public water infiltration gallery
located North and West of 1-90 in T7N, R2E, Sections 28, 33,
and 34. in Lawrence County near Spearfish, South Dakota We
disagree with Weston W Wilson, Project Officer and Frederick
Huff, EPA. counsel of Denver, Colorado, and Carol Koemer's
November 20, 1980 oral suggestions that mound type systems
would offer the Belle Fourche public water supply adequate
and acceptable protection from coliform contamination We
object to the arbitrary attempts of EPA representatives and
Carol Koerner to vary the terms of the October 31, 1979
Agreement negotiated by representatives of seven (7) govern-
mental entities after more than seventeen (17) months of
meetings, discussions, and costly studies conducted by geolo-
gists, hyrologists, and engineers You will find enclosed a
clipping from the November 7, 1979, Spearfish, South Dakota
Queen City Mail which summarizes the plans of the seven (7)
governmental entitles for solving the water pollution problem
Since the October 31, 1979 meeting the following has been
accomplished
-•BVV
- KA
Dft*
HO
Bf*1 At
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Mr. Roger L Williams
November 26, 1980
Page Two
1 The Department of Water and Natural Resources
of the State of South Dakota has issued a mandate to the
Lawrence County Commissioners and to Lawrence County Zoning
and Planning that the moratorium on building permits must be
continued for individual subsurface sewer systems in the area
of the Belle Fourche infiltration gallery
2 The chairman of the Lawrence County Commissioners
and the mayor of the City of Belle Fourche have written letters
and have directed that telephone calls be made in an attempt to
obtain a priority listing for preparation of a detailed flood
hazard way map in the area around the Belle Fourche water in-
filtration gallery.
3 The Lawrence County Zoning commission amended its
comprehensive plan to require connection to a central sewer
system (See Ordinance 4 3.2.A attached hereto.)
4 The Spearfish Valley Sanitation District annexed
the area around the infiltration gallery which includes the
Weiss-West subdivision I have attached a newspaper clipping
of the Lawrence County Commissioners proceeding for February
6, 1980 which relates the annexation proceeding Page 94 of
the Draft Environmental Impact Statement should be corrected
to reflect this annexation
5 On November 25, 1980 representatives of the
Spearfish Valley Sanitary District and Scott Engineering re-
viewed the route of the proposed eight inch (8") sewer inter-
ceptor line and force main and pump station. We are informed
that a cost analysis is being prepared and will be submitted
to EPA
6 On November 20th the Citizen's Advisory Committee
recommended that Spearfish Valley Sanitary District proceed to
make applications to EPA for construction grants for a 4,000
foot line and 2,050 foot force main
In summary, the City of Belle Fourche strongly
approves the written decision of EPA as set forth on pages 7
and 8 of the Draft Environmental Impact Statement of Spearfish
Sewerage Needs in Lawrence County, South Dakota We believe
that construction of an interceptor sewer is the only accept-
able protection for our public water supply
Very truly yours,
JXTT~T5?\ BELfcfc FOHRCHE ^
Rob££&>L Helmer. Mayor
Enc
EPA la aware that the City of Belle Fourche and Lawrence
County are discussing the possibility of allowing eeptlc
systems with holding tanks in the area It is the opinion of
EPA and the State Department of Water and Natural Resources
that If holding systems are properly maintained it would meet
the requirement of a norltorlum on subsurface disposal systems
EPA is especially appreciative of the City of Belle Fourche's
efforts to assist Lawrence County In conducting the necessary
floodplain mapping. EPA hopes Belle Fourche will continue to be
interested In conditions of development in the floodplain as the
Lawrence County Commissioners develop their floodplain management
program.
Acknowledge
Acknowledge
The engineering cost analysis prepared by Scott Engineering
will soon be completed. It Is expected that the Spearfish
Valley Sanitation District will apply for a federal wastewater
treatment grant for an Interceptor as described in this Impact
statement.
Acknowledge. See Chapter 6.
Finally, EPA accepts Belle Fourche's endorsement of the
written decisloo In the draft EIS and concurs that
construction of an interceptor aewer will provide some pro-
tection of Belle Fourche's public water supply. Note further,
however, that due to suspected nonpoint source problems
unassoclated with septic systems, the infiltration gallery
shall be considered a surface water source. Therefore, further
physical protection la needed.
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Advisory
Council On
Historic
Preservation
1922 K Slrml NW Rapty to Lake Plau South Suite 010
Waihinftoo. DC 2QOOS 44 Urunri Bouinvard
Lskewood CO 60226
November 13, 1980
Mr. Roger L. Williams
Regional Administrator
Environmental Protection Agency
i860 Lincoln Street
Denver, Colorado 60295
Dear Mr. Williams
Tbe Council has received your draft environmental statement (DES) for
Spearfleh> Soutb Dakota sevage needs circulated for comment pursuant to
Section 102(2)(C) of the National Environmental Policy Act Ue note that
particular mention 1b made of possible effects to the McGui-gan Farmstead, a
property possibly eligible for the Rational Register of Historic Places
Tbe Environmental Protection Agency should contact tba State Historic
Preservation Officer for assistance In evaluating the significance of the
Farmstead for Its National Register eligibility and include these comments
la the final environmental statement Circulation of a DES does not
fulfill your agency's responsibilities under Section 106 of the National
Historic Preservation Act of 1966 (l6 U S C Sec. l*70f, aa amended, 90
Stat 1320)
Prior to tbe approval of the expenditure of any Federal funds or prior to
1 the granting of any license, permit, or other approval for an undertaking.
Federal agencies oust afford the Council an opportunity to comment on the
effect of tbe undertaking on properties included in or eligible for
Inclusion In the National Register In accordance vitb the Council's
regulations, "Protection of Historic and Cultural Properties" (36 CKR Part
800) Uotll these requirements are met, the Council considers the DES
incomplete in Its treatment of historical, arcbeological, architectural,
and cultural resources You should obtain the Council's substantive
comments through the process outlined in 36 CFH Sec. 600.9- These comments
should tben be incorporated into any subsequent documents prepared to laeet
requirements under the National Environmental Policy Act. Ms Marjorle
Ingle may be contacted at (303) 23l»-l*9!*6 for further assistance
Sincerely,
Chief, Uedtcin Division
Ui
e
of Project Review
Since no action la th£ recommended alternative In
the ares of the McGulgsn Farmstead, the project should
not disturb the site In any way.
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Advisory
Council On
Historic
Preservation
RepJy to. Lake Plata South Suite 010
44 Umoo BouJevard
Lakewood GO902U
1922 K SlrMt NW
Wsthwfioa. DC 20003
December 23, 1980
Mr Alan Hereon
Regional Administrator
Environmental Protection Agency
1860 Lincoln Street
Denver. Colorado 80295
Dear Mr. Hereon.
We have reviewed the environmental assessment-negative declaration dated
October 27, 1980, Cor the wastewater treatment plan for Spearflsh, South
Dakota, received on November 3, 1980. There appeara to be some confusion
about the uae of the Council's regulations, "Protection of Historic and
Cultural Properties" (36 CFR Part 800) from statements made In thla envir-
onmental assessment and chose In a June 12, 1960 cover letter from Mr J.
Williams Gelse, Jr., In response to our Hay 16, 1980 review of the April
1980 environmental review of thla project. The material sent with the
June 12 letter was not sent In fulfillment of Section 106 of the National
Historic Preservation Act of 1966. A request for comments pursuant to
Section 106 must be done In accordance with the Council's regulations and
aent with the appropriate supporting documentation (see Section 800 13 of
the Council's regulations). As set forth In Section 800 4 of the Council's
regulations, the Council must be afforded an opportunity to content If the
agency determines that the project will effect properties on or eligible
for the National Register of Historic Places» regardless of whether the
effect Is adverse or not However, a comparison of the two environmental
documents Indicates conflicting determinations of effect. In the earlier
environmental review. It la stated that the South Dakota Department of
Education and Cultural Affairs have assessed the wastewater treatment
project as having no sdverse effect on cultural or historic properties,
yet, in the October 27, i960 environmental assessment. It is stated that
the South Dakota State Historic Preservation Officer has informed EPA
that the proposed project will have no effect on cultural resourcea
RESPONSE. 1* The determination of "no effect" la from page 16 of the
October 27, 1978 document, "Environmental Assessment,
Wastewater Treatment Facility Plan for Spearflsh, South
Dakota", while the "no adverse effect" determination Is from
page 2 of a document dated 30 April 1980 and entitled "Amendment
to Findings of No Significant Impacts, Project Wastewater Treat-
ment Facility". The action associated with these reports is
associated with tbe Spearflsh wastewater treatment facility
snd not the sewerage needs which are addressed In this E1S. In
any case, neither project should have any effect on these sites.
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Page 2
Mr. Alan Merson
Speerflah Uucevster
December 23, 1960
^I Please verify your determination of project effect and. If appropriate,
I request Council consent In accordance with the Council's regulations.
On November 9, I960, we received a telephone call from a staff member of
the South Dakota State Historic Preservation Officer In response to an earlier
call from a representative of the U.S. Pish and Ulldllfe Service. The Fish
and Wildlife Service la concerned that pollution In Spearfl9h Creek might
necessitate the closing of the Spearflsh Hatchery, a property included In
^ the National Register of Historic Places. Evidently, the existing situation
Is having an effect on a National Register property, however the environmental
assessments do not address this effect. Please contact the Fish and Wildlife
Service and evaluate the effects of the various project alternatives on the
Spearflsh Hatchery, In consultation with the South Dakota State Historic
Preservation Officer.
If you have any questions, please contact Marjorle Ingle of my staff at
234-4946
Sincerely
c—
Louis S y* 11
Chief,c"Western Division
of Project Review
2. Water quality effects of the no action alternative in Mountain
Plains to Spearflsh Creek and the Spearflsh National Fish
Hatchery have already been addressed In reaponse to a letter
from the U.S. Fish and Wildlife Service (pages A-7 through A-10).
-------
SUMMARY OF WATER QUALITY STUDIES
APPENDIX B
&
-------
APPENDIX B
SUMMARY OF WATER QUALITY STUDIES
In order to evaluate the assembled data in a meaningful manner It Is
necessary to identify the issues which are pertinent to the study. As the
EIS progressed issues were identified through the public participation
process, the input of the citizens advisory group, and data manipulation.
The following issues were identified as significant:
. The source of sporadic groundwater contamination at and
around the Belle Fourche infiltration gallery.
The cause of surface water contamination in Higglns Gulch
and Spearfish Creek.
Septic rank failures identified by EPA's aerial imagery photography.
Groundwater contamination in the Higgins Gulch area, Mountain
Plains area and Christensen Drive area.
The suitability of septic tanks as a means of sewage disposal in
the areas outside of Spearfish.
Water quality data at the gallery are available back to 1967. However,
the period of record is fragmented with no data available for the following
years: 1969, 1970, 1971, 1972, and part of 1973. The record of data is
further complicated by an inconsistency in the parameters monitored. In
1967 and 1968 total coliforms were the major parameter monitored, then in
1973, 1974, and the first half of 1975 samples were monitored for fecal
coliform and fecal streptococci. One sample (7-16-73) was monitored for
total coliform. From 8-26-75 total coliforms were monitored only until
9-9-77. In the summer of 1978 extensive monitoring was done at and around
the gallery of both the surface water and groundwater.
The earliest date of contamination at the gallery is 8-7-67 when
total coliforms numbered 3.6/100 ml. Contamination is also noted on 11-6-67,
11-20-67, 10-7-68, and 11-4-68 when each total coliform count was 2.2/
100 ml. From 5-6-73 to 5-6-75 fecal coliform counts were mainly 2/100 ml,
on 5-6-73, and on 7-31-73 counts were 3/100 ml, and on 5-7-74 a count
of 4/100 ml was reported. On 7-16-73 a total coliform count of 16/100 ml
is reported but fecal coliform were not tested for. From 8-26-75 to
5-10-78, 14 out of 40 monitoring events indicated contamination. Consis-
tent contamination of the gallery was observed in the last half of 1978
but currently no contamination is reported.
B-l
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Because Che most comprehensive data for both surface water and
groundwater quality are the result of the special studies conducted in
1978, and because of the inconsistencies in the historic data collected
at the gallery, the special studies data are used to evaluate the gallery
contamination problem.
Total coliform is the principal indicator of groundwater contamina-
tion. Fecal contamination occurs very sporadically at the groundwater
monitoring sites. Surface vatexsin Spearfish Creek have fecal coliform
counts that are as high as 370/100 ml, while most samples are between
30/100 ml to 90/100 ml. Total coliform data In Spearfish Creek are not
adequate to evaluate. Surface water in Higgins Gulch has very high
total coliform counts by comparison. All values are above 340/100 ml,
with a maximum count of 15,000/100 ml reported on 7-7-78. Fecal coliform
counts have a high of 276/100 ml, with most values between 30/100 ml
and 90/100 ml.
It has been demonstrated that groundwater at the gallery is recharged
by water from both Higgins Gulch and Spearfish Creek and that groundwater
movement from the Higgins Gulch is in a northeasterly direction. Thi3
condition is a result of the groundwater from Higgins Gulch moving through
the alluvial material in its stream bed entering the Spearfish Creek
alluvium.
Sewage disposal by septic tanks and absorption field is practiced at
the Vest Development and by one home in the Weiss Development which are
within a few hundred feet of the infiltration gallery. These systems are
located in the same alluvial deposits of the Spearfish Creek bottomland
that the City of Belle Fourche has their infiltration gallery. The next
closest concentration of developments using septic systems are in the
Higgins Gulch area, about three miles away from the gallery. These develop-
ments are located on the Spearfish Creek bench areas. Soils, according to
SCS, are of a clay-loam and because of their slow permeabilities not suited
for septic tank absorption fields unless they are enlarged. (Soil permea-
bilities are summarized in Table 41).
On 6-16-78 groundwater contamination was identified at the gallery,
Cundy drain, the well at Abernathy's and the Ward well. Surface water
contamination is also Indicated at three sites in Higgins Gulch. During
the 24 hour period prior to the monitoring day a trace of precipitation
is recorded, and five days prior 0.15 inches of rain occurred. Contamina-
tion at the gallery, Cundy's drain, Higgins Gulch also occurred on 6-23-78.
B-2
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Forty-eight hours before and five days prior 0.07 inches and 0.62 inches
of rain fell, respectively. The next monitoring period, 6-29-78, high
coliform contamination at the gallery, Cundy's drain, Ward well, and the
spring above Ward's and Higgins Gulch occurred. During a 48 hour
period from 6-28-78 to 6-29-78 over 0.27 inches of rain fell in the
study area. On 7-7-78 water quality samples were collected again. A
lower coliform contamination than the previous sample is noted. Rain,
totaling 0.85 inches fell from 7-5-78 to 7-7-78. On 7-14-78 coliform
colonies have shown an increase over the previous monitored sample at
the gallery, Cundy's drain, and Ward's well, but Higgins Gulch concentra-
tions have decreased. No rain fell since the last monitoring. Coliform
colonies dropped at all stations on 7-21-78 except the Cundy drain
where they remained static and the spring above Ward's. Over 0.39 inches
of rain fell during the 24 hour period prior to monitoring.
In conclusion, there is a correlation between rainfall events and
contamination at the gallery (i.e. higher coliform concentrations follow
rain and subsequent runoff).
Storm events are carrying different concentrations of conforms off
the land surface via runoff. These concentrations vary with land use
within the drainage and rainfall intensity. Typically a rainfall event
will initially flush the surface, delivering high concentrations to surface
waters. See Higgins Gulch data and rainfall records for 7-7-78 and 6-29-78
and Spearfish Creek 9-18-78.
The contaminated material will be generated by both developed and
undeveloped land and is commonly referred to as non-point source contamina-
tion.
As the runoff moves down the drainage surface water elevations rise.
Groundwater elevations in the gallery area will increase due to the increased
water flowing in Spearfish Creek and Higgins Gulch. As the groundwater
elevation rises the potential for short-circuiting of the septic tank
absorption field in the alluvium increases, thus contributing to the
coliform contamination that has been carried into the groundwater from
the surface water. Because of the defined movement of the groundwater the in-
filtration gallery becomes contaminated. This situation can be compounded
B-3
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if Che storm occurs In the gallery area. A high intensity rain on permeable
soils will experience a downward flushing action as opposed to a runoff
effect more typical of tight clays. As the rainfall percolates through
alluvium it will have a flushing effect, transporting the absorption field
contaminants deeper toward the groundwater.
It is therefore concluded that the sporadic contamination of the
Belle Fourche infiltration gallery is a consequence of non-point source
originating from runoff over livestock pasturing, and confinement areas,
urban areas, and undeveloped areas. These sources are also contributing
to the surface water contamination in Higglns Gulch and Spearfish Creek.
The suspected septic 3ystem failures identified by EFA's aerial imagery
have been discussed In the Aerial Imagery Section. Two of the systems
were confirmed as actual failures and thirteen were identified as poten-
tially falling during wet periods. Because these systems are confirmed
through surface manifestations it is concluded that tight, Impervious
soils are causing these problems. Therefore, these systems cannot be
creating any groundwater degradation.
With the exception of the Christensen Drive area, existing data do
not indicate that the groundwater in the vicinity of Higglns Gulch near the
Deer Meadows, Deberg-Fuller developments or the deep aquifer which is
partially recharged in the Mountain Plains area are contaminated. However,
because the available data were not collected during the period of seasonal
high groundwater additional studies will be conducted. This additional
work will evaluate the seasonal high groundwater depth and its quality
In the Spearfish and Higglns Gulch alluvium and the two perched water
table areas located in the old terrace deposits. This work will be com-
pleted by July 1, 1979. There are no plans at this time to monitor
the deep aquifer in the vicinity of Mountain Plains because of the very
low density of development. However, surface water quality in Spearfish
Creek is being monitored by the U.S. Fish and Wildlife service. This program
is a consequence of the potential for non-point source contamination
originating from Mountain Plains development interferring with the operation
of the Spearfish Fish Hatchery.
B-4
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A shallow well at the mouth of Chrlstensen Drive has been abandoned for
domestic use due to coliform contamination. The source of contamination is
likely caused by development in the alluvial valley upstream of this well.
Septic tanks in this area, particularly those serving the campgrounds on
the north side of the valley, are suspected as failing seasonally, and
those in the shallow alluvium of the valley bottom are probably the contri-
buting factors along with non-point sources in contamination of this well.
The reason this shallow aquifer is contaminated by septic discharges
while the Spearfish Valley is not, is attributable to the small confined
nature of the shallow alluvium underlain by impervious materials.
In summary, the findings to date indicate that septic tank systems are
a feasible means of sewage disposal in areas outside the City of Spearfish
and above the Spearfish alluvial valley. Because of the Impermeable soils,
the absorption fields must be constructed larger than the State code
requires and the systems will potentially function as evapotranspiration
systems as opposed to the conventional leach field system. There would be
no problem in extending these fields as all lots outside the city are
generally one-half acre or larger. The tighter soils and the associated
evapotranspiration should afford protection of groundwater in these
developed areas.
At this time no public health hazards are identified in the Mountain
Plains area relative to septic tank systems. The Mountain Plains area does
have a high potential risk of contaminating the Minnelusa aquifer if con-
ventional septic systems are used to dispose of wastewater as development
density increases. Therefore, the approval and installation of the
systems must be monitored on an individual site basis. The ultimate suc-
cess or failure of on-site disposal systems will be determined by the
Lawrence County Planning and Zoning Commission, and the Northern Hills
Sanitarian. Based on SCS soil interpretation, areas of septic tank limi-
tations are illustrated in Figure 20. This data along with data collected
through septic tank permitting and data presented during this project should
be utilized in future septic tank review/approval.
B-5
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TECHNICAL REPORT DATA
//lease read Insmicnons on the reverse before completing)
1 REPORT NO
EPA-908/5-80-002B
3 RECIPIENT'S ACCESSION NO.
4 TITLE AND SUBTITLE
Final Environmental Impact Statement
Spearfish Sewerage Needs
Lawrence County Near Spearfish, South Dakota
5 REPORT OATE
October 10, 1980
6. PERFORMING ORGANIZATION CODE
7 AUTHOR(S)
Weston W. Wilson, EPA
Paul Seeley, Engineering-Science
8. PERFORMING ORGANIZATION RE'ORT NO
9 PERFORMING ORGANIZATION NAME AND AOOR6SS
Engineering-Science, Inc.
2785 North Speer Blvd., Suite 140
Denver, Colorado 80211
10 PROGRAM ELEMENT NO.
11 CONTRACT/GRANT NO.
12. SPONSORING AGENCY NAME AND AOORESS
U.S. Environmental Protection Agency
Region VIII
1860 Lincoln Street
Denver, Colorado 80295
13 TYPE OF RE'ORT ANO PSRIOO COVERED
Final
14. SPONSORING AGENCY COOG
8W-EE
15 SUPPLEMENTARY NOTES
Environmental Assessment dated April 30, 1980; Draft EIS issued October 10, 1980
Spearfish Wastewater Treatment System also issued by EPA
16 ABSTRACT
Surface and groundwater pollution problems have been identified in Spearfisn
Creek, Higgins Gulch, Christensen Drive, and the Belle Fourche infiltration aallery.
Surface water quality problems have been demonstrated no be associated with nonpoint
source pollution; while groundwater pollution in Christensen Drive and at the Belle
Fourche infiltration gallery have been influenced by septic tank systems located in
the alluvial bottoms of streams and by nonpoint sources.
In order to correct the water quality problems of the area it is recommended that
nonpoint source control strategies be implemented and two new interceptor sewers be
constructed. Based on local and state requirements, these interceptor sewer lines car
only be funded if these unincorporated areas are incorporated into the City of
Spearfish or into the Spearfish Valley Sanitation District. The estimated capital cosft
of the interceptors is $175,155.
17
<£V WOROS ANO OOCUMENT ANALYSIS
DESCRIPTORS
b IOENTI FI E RS/OPEN ENOEO TERMS C COSATI Field/GfOUp
Sewer Interceptor
Groundwater Pollution
Individual Disposal Systems
Infiltration Gallery
Environmental Impact Statement
Town of Spearfish
Town of Belle Fourche
Black Hills
18 OIST^J SUTION STATs S46N7
3el ease llnl imi ted
19 SECURITY C-.AS5 {t nts Reoort)
| 21 NO OP ?aGc5
I 174
|*Q SECURITY CLASS iTm: page)
!22 3RICS
E?A form 2220 — 1 (Re* 4—77)
sopviCuS
¦3ITION iS C9SOL£"E
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