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i'DKIQS and Stokes Associates, lac, SsiFOiHSr.t'O
Prepared for
Environmental Protection Agency, Scarify VJA Region X
1979
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TECHNICAL REPORT DATA
(PIrase reed inumi (tons on the rcve*Je before complrnng)
' ^9-79-063
¦S TITLE AND SUBTITLE
SEWAGE EFFLUENT DISPOSAL FOR THE CITY OF BEND,
OREGON
5 REPORT DATE /
' ( . _ 1979
& PERFORMING ORGANIZATfON CODE
7 AUTHOH(i)
B PERFORMING ORGANIZATION REPORT NO
9 PERFORMING ORGANIZATION NAME ANO ADDRESS
Jones & Stokes Associates, Inc.
2321 P Street
Sacramento, CA 95816
10. PROGRAM CLEMENT NO.
1t CONTRACT/GRANT NO
12 SPONSORING AGENCY NAME AND ADDRESS
U.,S. Environmental Protection Agency
Kegion X
1200 Sixth Avenue, Seattle, ''A 98101
13 TYP£ OF REPORT ANO PERIOD COVERED
E1S
%A SPONSORING AGENCY CODE
IB SUPPLEMENTARY NOTES
»
The City of Bend, Oregon has proposed to construct a new 6 million gallons per
day (mgd) secondary treatment plant to replace the present facility which
treats an average of 0,5 mgd. The majority of domestic wastes are currently
disposed of through septic tanks discharging to lava sink holes or drill holes.
These waste disposal wells ha*'e been declared a potential public health' hazard
because they Te&teh potential for contamination of domestic water supply wells
which are numerous'm the area. » propertyofUS Envir0nmental
Protection Agency Ljbrary MD-108
i
I
-OCT 0 3 |989
1200 Sixth Avenue/Seattle, WA 98101
KEY WORDS AND DOCUMENT ANALYSIS
DESCRIPTORS
b IDENTIFIERS/OPEN ENDED TERMS C COSATI Held/Group
Sewage Tieatment Plants
Ground water
Bend, Oregon
Bend, Oregon
8 DISTRIBUTION STATEMENT
unlimited distribution
19 SECURITY CLASS tThu RrporlJ
uncLassitied
21 NO OF PAGES
20 SECURITY CLASS (This page)
unclassified
uosfrof
FPA Form 2220*1 (9 73)
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SEWAGE EFFLUENT DISPOSAL FOR
THE CITY OF BEND, OREGON
Prepared By:
Jones & Stokes Associates, Inc.
2321 P Street
Sacramento, CA 95816
In Association With:
Gulp, Wesner and Gulp
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TABLE OF CONTENTS
Pa£e
SUMMARY 1
CHAPTER 1 - INTRODUCTION 7
Background of Past Events 7
Effluent Disposal Alternatives 10
Problem Description/Issues 10
Necessity/Purpose of EIS 10
CHAPTER 2 - AFFECTED ENVIRONMENT 13
Introduction 13
Location 13
Climate 13
Land Resources 13
Topography 13
Geology 15
Soils 15
Land Use 16
Water Resources 16
Surface Water Quality/Quantity 16
Groundwater Quality/Quantify 17
Water Supply and Beneficial Uses 18
Flood Hazards 18
Air Quality 18
Biological Resources 19
Flora 19
Fauna 19
Rare and Endangertd or Threatened Species 20
Archeological and Historical Resources 20
Aesthetics 20
Social Environment 21
CHAPTER 3 - WASTEWATER CONVEYANCE, TREATMENT AND
DISPOSAL SYSTEMS
Introduction 23
Historical Wastewater Handling Systems 23
Existing Wastewater Handling Systems 25
Future Wastewater Handling Systems 28
The Stevens, Thompson S> Runyan Engineers
Facilities Plan (STR) 28
The Modified Facilities Plan (BECON) 30
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Page
CHAPTER 4 - ALTERNATIVE EFFLUENT DISPOSAL AND
REUSE SYSTEMS 39
Introduction 39
Screening of Effluent Disposal and Reuse
Alternatives 39
STR Proposed Alternatives 40
Proposed Effluent Disposal and Reuse
Alternatives 42
Subsurface Disposal 42
Discharge to the Deschutes River 44
Discharge to Sealed Evapotransp;ration
Ponds 44
Land Application by Spray Irrio-3tion 47
Discharge to the North Unit Ma^n Canal 50
No-Action Alternative 51
CHAPTER 5 - LEGAL, POLICY AND INSTITUTIONAL
CONSTRAINTS 53
Environmental Requirements (General) 53
Cultural Resources and Land Use Constraints 54
Water Pollution Control 56
Water Quality Standards and Effluent Disposal 59
CHAPTER 6 - EFFECTS OF THE ALTERNATIVES ON
ENVIRONMENTAL RESOURCES 63
Introduction 63
Short-Term Impacts 63
Primary and Secondary Long-Term Impacts 67
Reliability 68
Groundwater 69
Surface Waters - Deschutes River 82
Surface Waters - North Unit Main Canal
System 8b
Public Health 89
Fisheries 99
Wildlife 101
Vegetation and Soils 101
Land Use 102
Odors 102
Noise 102
Aesthetics 103
Archeology/History 103
Resource Consumption 105
Monetary Costs 105
Mitigation_Measures 114
iii
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Page
Local Short-Term Uses of the Environment vs.
Maintenance and Enhancement of Long-Terra
Productivity 118
Irreversible and Irretrievable Commitment
of Resources 119
Unresolved Issues 119
CHAPTER 7 - LIST OF PREPARERS 121
CHAPTER 8 - BIBLIOGRAPHY 123
CHAPTER 9 - APPENDICES 129
IV
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LIST OF FIGURES
Fiqure
Page
2-1
Study Area
14
3-1
Diagram of a Typical Domestic Sewage
Disposal System in the Bend Area
24
3-2
Existing Sewerage Systems
26
3-3
Lava Tube Effluent Disposal From the
Existing Wastewater Treatment Plant
27
3-4
A Sample of Water Wells in the Bend
Area
29
3-5
Treatment Plant Locations and Proposed
Effluent Disposal Areas (Sites C & E)
31
3-6
Schematic Diagram of Proposed Treatment
Plant
33
3-7
Preliminary Plant Layout
34
3-8
Projected Annual Average Wastewater Flows
35
4-1
Potential Location of Infiltration Pond
and Gravity Pipeline
45
4-2
Proposed Effluent Disposal Outfall to
the Deschutes River
46
4-3
Potential Location of Pipeline/Canal
Route and Ponded Areas
48
4-4
Potential Sites for Land Application by
Spray Irrigation
49
6-1
Idealized Plume of Effluent from Site E
74
6-2
Flow in a Water-Table Aquifer
76
6-3
Potential Mechanism for Contamination of
Uncased Well
77
6-4
Locations of Domestic Water Diversions
and Recreational Use on the Deschutes
River Below Bend
84
6-5
The North Unit Irrigation District
Canal and Reservoir System
86
6-6
Historical Roads m the Project Area
104
6-7
Primary Energy Use
106
6-8
Estimated Secondary Energy Requirements
107
6-9
Estimated Present Worth Values
108
6-10
User Charge Per Home
110
v
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LIST OF TABLES
Table Page
3-1 Monthly Wastewater Volumes and Average
Daily Flows (Based on a 6 MGD Annual
Average Daily Flow) 36
3-2 Summary of Effluent Quality (City of
Bend Wastewater Treatment Plant) 38
4-1 Anticipated Effluent Quality for Each
Major Alternative 43
6-1 Short-Term Impacts Bend Effluent Disposal
Alternatives 64
6-2 Morphometric Data for Haystack Reservoir 87
6-3 Removal of Coliforms by Sedimentation in
Saturated Sand of Various Effective Sizes 91
6-4 Soil Texture and Colifcrm Count at a Depth
of 3 Feet For Five Soils Upon Which
Sewage Was Spread 97
6-5 Projected 1979 Use and Costs of Aquatic
Herbicides - North Unit Irrigation
District 112
VI
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SUMMARY
Background
Adequate sewage treatment in the City of Bend, Oregon is
provided for approximately 10 percent of the city's population
by the city secondary wastewater treatment plant. Disinfec-
tion effluent produced by the plant is discharged into a lava
sink hole on the plant site. At present the treatment plant
treats an average sewage flow of 0.5 million gallons per day
(mgd).
The majority of domestic wastes, however, are disposed
of through septic tanks discharging to lava sink holes or
drill holes. Approximately 6,000 to 7,000 of these waste
disposal wells are currently utilized in the Bend area.
These waste disposal wells have been declared a potential
public health hazard by the Oregon State Department of Environ-
mental Quality (DEQ) because they create a potential for con-
tamination of domestic water supply wells, which are also
numerous in the Bend area. Subsequent DEQ regulations pro-
hibiting construction and use of waste disposal wells after
1980 prompted the city to study alternative methods of
treating domestic wastes.
As a result of these studies, the city proposed to
construct a new 6 mgd secondary wastewater treatment plant
at a new location approximately 4 miles northeast of the
city. The existing treatment plant would be abandoned due to
a potential for significant adverse environmental impacts
associated with its expansion. Effluent produced by the new
treatment plant would be discharged to the subsurface on an
interim basis with a final method of effluent disposal to be
determined at a later date.
In 1978, the Environmental Protection Agency (EPA)
issued a Negative Declaration for design and construction
of the new treatment plant, which is currently under
construction. The EPA, however, decided to prepare an
Environmental Impact Statement (EIS) on the ultimate method
of effluent disposal because of the potential for adverse
environmental impacts assoc_ated with the proposed interim
method of effluent disposal.
1
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Effluent Disposal Alternatives
Five major alternatives of effluent disposal from the
new wastewater treatment plant are described and evaluated
in this document. These are: 1) subsurface disposal via
drill holes or infiltration ponds near the treatment plant;
2) discharge to the Desch'.tes River below the Bend diversion
dam; 3) discharge to evapotranspiration ronds (i.e., sealed
ponds developed as wildlife habitat) extending in a north-
east direction from the treatment plant; 4) land application
by spray irrigation of a harvestable grass crop; and
5) discharge to the North Unit Main Canal, which includes
modifications to year-round canal discharge to avoid dis-
charging effluent to an empty canal. The "No-Action"
alternative, which would be a continuation of existing
wastewater treatment and disposal methods (i.e., secondarily
treated, disinfected effluent discharged to a lava sink hole
and inadequately-treated wastes discharged to disposal wells)
is also evaluated.
Effluent treatment processes would vary under the
proposed alternatives. Advanced wastewater treatment
employing sand filters for bacteria and virus removal would
be used for effluent discharge to the subsurface vin drill
holes, the Deschutes River and the North Unit Main Canal.
Effluent quality would be less stringent for discharge to
infiltration ponds, evapotranspiration ponds and land irri-
gation systems, which would utilize natural filtration
processes to purify the effluent.
Environmental Effects of the Alternatives
and Mitigation of Adverse Impacts
Short-term construction-related impacts of varying
magnitudes would occur with all alternatives except the no-
action alternative. These impacts would include temporary
loss of vegetation, disruption of wildlife, dust and aerial
pollutants, soil erosion, noise, visual impects, traffic
congestion, safety hazards and water quality impairment.
Long-term impacts of the major alternatives are summarized
in Table A. Major adverse impacts associated with particular
alternatives are described below.
The major adverse impact associated with subsurface
disposal to drill holes would be the potential for ground-
water contamination, which could adversely affect domestic
well water use and pose a throat to public health.
2
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Table A
SUMMARY OF LONG-TERM IMPACTS - MAJOR ALTERNATIVES
Major Alternatives-*-
EanS
Subsurface Evapo- Application North
Drill
Infiltration
Deschutes
transpiration
by Spray
Unit Main
Ko
Environmental Element Holes
Ponds
River
Ponds
Irriqation
Canal
Action
Potential Ad/erse Isrpacts:
Surface vater quality
-
+
-
-
+
-
Croiir.dwat et +
0
-
-
0
0
+
Public Health +
0
+
0
0
+
+
i? a stories, -
-
+
-
-
+
-
Wildlife ;
0
-
+
+
-
-
Vegetationiand soils -
0
-
+
+
-
-
Lard use
0
-
0
+
-
-
Odors
0
-
0
0
-
+
Noise -
-
0
-
0
-
+
Aesthetics
-
+
-
0
+
Archeology/h?story
0
-
+
+
-
Resource consumption 0
0
+
0
+
0
-
User costs 0
0
+
•f
+
0
-
Other direct costs - ¦» #
-
-
-
+
-
Ability to expand - 0
—
+
+
—
+
Potential Beneficial impacts:
Wildlife -
0
-
+
0
-
-
Vegetation arid soils
-
-
-
+
-
-
Aesthetic.'.
-
-
+
-
—
-
^ ¦» Signifi<;ant inpact
0 L todcrate impact
- Negligible or no impact
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Establishment of an extensive groundwater monitoring program
prior to any subsurface disposal of effluent is suggested as
a mitigation measure to aid in estimating groundwater con-
ditions below the disposal site and attenuation of pollutants
once they enter the ground. In the event of domestic well
contamination, new wells could be drilled to the deep artesian
aquifer.
Major adverse impacts of subsurface disposal via
infiltration ponds would be a significant land commitment,
potential vector problems and a reduced potential for ground-
water contamination. Potential mitigation measures include
use of insecticides to control mosquitos, proper maintenance
of infiltration ponds to prevent clogging of the filtering
medium and a small-scale monitoring program to detect ground-
water contamination below the site.
Major impacts of effluent discharge to the Deschutes
River would be adverse effects, particularly in summer, on
water quality and fisheries resources. Downstream domestic
water use might be precluded as a safeguard to public health.
Potential mitigation measures -include upgrading the treatment
process to reduce water quality degradation and the potential
for ammonia and chlorine toxicity to aquatic life and develop-
ing alternative sources of drinking water for domestic users
downstream.
Major adverse impacts associated with development of
evapotranspiration ponds wculd be a large land commitment,
loss of native wildlife habitat, a public health risk from
insect vectors or effluent contact, a high initial capital
expenditure and high aser costs. Wildlife habitat losses
should be mitigated by creation cf new aquatic habitat that
would benefit native spfecies in surrounding habitat as well
as attract new species to the area. Insect vectors could be
controlled using insecticides or through natural means. To
protect against diseases, contact with undiluted, unpuiified
effluent in the first pores of the series could be prevented
by fencing. Public education programs would be beneficial.
Major impacts associated with land application by spray
irrigation include a high initial capital expenditure, high
operation and maintenance costs, a large land commitr.ient,
reduced ability to accommodate future expansion and a signifi-
cant loss of vegetation and associated wildlife. Wildlife
habitat losses could be slightly mitigated by enhancing
adjacent native habitat.
4
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Major adverse impacts of discharge to the North Unit
Main Car.al include public health risks to domestic water users
in the City of Madras, accelerated eutrophication of the canal
system and Haystack Reservoir, impacts of the reservoir
fisheries increased costs to the North Unit Irrigation District
for control of increased aquatic weed growth and for liability
insurance and potential groundwater contamination from seepage
in winter. As a mitigation measure, an alternative source of
domestic water could be developed for the City of Madras.
Nutrient removal by advanced wastewater treatment would reduce
the potential for accelerated eutrophication and adverse
impacts on the fishery. Increased costs of aquatic weed
control could be mitigated by improving effluent treatment
through nutrient removal or by reimbursing the District for
estimated increased expenditures. The City of Bend could
assume liability for public health risks to irrigators and
recreationists. A small-scale monitoring program could be
developed to detect any groundwater contamination from canal
seepage in winter. Modifications to year-round canal disposal,
which would eliminate adverse impacts of winter discharge, are
indi cated.
The no-action alternative would allow for continued
disposal of inadequately-treated septic iank wastes once
the capacity of the existing treatment plant was exceeded.
The major adverse impact associated with this alternative
would be the possibility of groundwater contamination and
related public health risk from contaminated domestic well
water. As the population in the Bend area increases, the
potential for groundwater contamination would also increase.
Complaints related to odors, noise and heavy truck traffic
would increase as residential developments grow ,around the
existing treatment plant.
5
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Chapter 1
INTRODUCTION
Background of Past Events
In 1970 the City of Bend population was 13,710 while
the urban area population was 19,150. By 1974 the estimated
city and urban population had grown to 17,215 and 25,690,
respectively. The year 2000 population for the urban area
is projected to be 60,000. Presently, about 10 percent is
being served by sewers and adequate sewage treatment.
In 1970 the City of Bend constructed a sewage collection
and treatment plant designed to serve a population of 20,000,
which would produce an average sewage flow of about 2 million
gallons per day (mgd). The facility provides secondary
treatment (actived sludge process) and discharges disinfected
effluent into a lava sink hole on the plant site. The plant
presently treats an average sewage flow of 0.5 mgd.
Five other wastewater treatment and disposal facilities
are operated in the study area. They are small units serving
apartment complexes and industries, and most are approved
for interim use until a regional sewage system becomes
available.
The majority of domestic wastes are disposed of through
septic tanks discharging to lava sink holes or drill holes.
Approximately 6,000 to 7,000 of these waste disposal wells
are currently utilized in the Bend area. This method of
disposal is necessary because the soil overburden is generally
less than 12 inches deep, which does not provide sufficient
surface leaching.
Although no evidence has been documented to date, these
several thousand waste disposal wells create a potential for
contamination of domestic well water supplies, and thus are
a public health hazard. A study done by the Federal Water
Quality Administration entitled Liquid Waste Disposal in
Lava Terranc of Central Oregon concluded that a continued
discharge of septic tank wastes to drill holes poses a
potential hazard to the quality of the groundwater (Sceva,
1968). Subsequently, the Oregon Department of Environmental
Quality (DEQ) promulgated legulations prohibiting the
construction .of additional lava sink holes for disposal of
inadequately treated wastes iiv the Bend urban area after
January 1975 and prohibiting their use.beyond January 1980.
7
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As a result of these regulations and a formal requirement
issued to the city by DEQ on September 5, 197 5 as part of the
waste discharge permit, the City of Bend initiated a study to
determine the proper treatment and disposal of sanitary
wastes for the Bend urban area. A report entitled Sewerage
Facilities Plan, City of Bend, Oregon was prepared for the
city in September 1976 by Stevens, Thompson & Runyan, Inc.
and Tenneson Engineering Corporation. In this document the
recommended plan called for expansion of the existing waste-
water treatment facility to a capacity of 6.0 mgd. Approximately
150,000 linear feet of collector and interceptor sewers would
be installed and disposal of treated effluent would be through
year-round spray irrigation on approximately 600 acres located
about 3 miles north of the treatment plant.
After environmental review of this document, the U. S.
Environmental Protection Agency (EPA) determined that the
proposed project did not constitute a significant action and
therefore did not require an Environmental Impact Statement
(EIS). On April 5, 1977, the EPA released a Negative
Declaration announcing its preliminary decision not to
prepare an EIS. This decision was based on the fact that
the proposed project conformed with the city's local land
use plan and with statewide planning goals and guidelines!
The city's proposed project to sewer the entire City of Bend
would also be necessary to comply with state water quality
regulations.
On July 8, 1977 upon completion of the 15-day comment
period on the Negative Declaration, the EPA awarded a Step II
construction grant to the City of Bend for design of the' proposed
project. After reevaluation of the proposed project, however,
the city decided to reject the plan approved by EPA and
instead proposed to construct a new secondary wastewater;
treatment plant at a site on Bureau of Land Management ('ELM)
lai\d approximately 4 miles northeast o^, the existing faqility.
The effluent would be filtered> disinfected and discharged
year-round to the subsurface via drill holes or lava tubes
or cracks on the new site as an interim measure with a
permanent disposal method to be proposed at a later date.
The existing treatment plant and disposal site would be
abandoned.
The city proposed this alternative to the EPA in Amendment
Number One to the Sewerage Facilities Plan in November 1977,
contending that a comparative cost analysis of the treatment
alternatives shoved-the -total cost was essentially the same
for either alternative. The city also contended that major
environmental impacts would occur if the existing plant was
expanded. Among these nuisance impacts were noise and odor
problems relating to recent residential developments around
the existing facility.
8
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To review costs associated with the two treatment plants
and relocation to the new site, the EPA contracted Brown and
Caldwell Engineers to perform an independent cost comparison
analysis. The Brown and Caldwell analysis reported that
construction of the new plant would be as cost-effective as
expansion of the existing plant. As a result, on April 5,
1978 the EPA issued a Negative Declaration for design and
construction of the new wastewater treatment plant, and
collector and interceptor sewers. However, because the
city*3 newly proposed project contained significant changes
in the method of effluent disposal, -J.ye EPA determined to
prepare an EIS on the ultimate means of effluent disposal.
In the event that the EPA has not selected a final
effluent disposal alternative when the new treatment plant
is ready for start-up (estimated August 1980), the City of
Bend has approval from the DEQ for use of subsurface disposal,
defined as a drill hole, as an interim method of effluent
disposal. Interim use of a drill hole was conditionally
approved by the E?A in a letter to the DEQ dated March 16,
1978.
Conditions that must be met before EPA can give final
interim approval to subsurface effluent disposal to a drill
hole are:
1. Disposal to a drill hole must be the only feasible
alternative available at the time of actual use.
2. The City of Bend must pursue and exhaust other
available interim or final disposal alternatives.
3. Discharge to a drill hole must be found to be
environmentally acceptable in this EIS.
4. The City of Bend must commit itself to aggressively
constructing the final disposal system to limit the
use, if any, of an interim solution.
5. A comprehensive groundwater monitoring program
approved by EPA must be established and operable
prior to the time of first discharge. This monitoring
program is intended to evaluate the fate and impact
of effluent on the receiving groundwater aquifers,
including the regional groundwater table.
More recently.- in Design Definition Memorandum #10
(June 1979), BECCrt has redefined subsurface disposal to
include gravity flow to drill holes, gravity flow to a lava
crack (or tube), areal percolation (through natural per-
colation or induced by blasting to fracture lava strata)
or pumped flow to injection wells.
9
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Effluent Disposal Alternatives
The major effluent disposal alternatives evaluated in
this EIS are: 1) subsurface disposal via drill holes or
infiltration, 2) discharge to the Deschutes River, 3) dis-
charge to the North Unit Main Canal, 4) land application
by spray irrigation, and 5) discharge to a series of sealed
po.ids developed as wildlife habitat. The no-action alter-
native, which would be continuation of the present methods
of effluent disposal (discharge of secondarily-treated
effluent to a lava tube from the existing wastewater treatment
plant and subsurface disposal of inadequately-treated wastes
from individual septic tanks) is also evaluated.
Problem Description/Issues
It is clear that there are several key environmental
and economic issues relating to the proposed, alternative
methods of effluent disposal. These issues became evident
through discussions with City of Bend officials, personnel
of various local, state and federal agencies and review of
relevant correspondence and reports.
The issues listed below are identified and evaluated
more fully in Chapter 6 - EFFECTS OF THE ALTERNATIVES ON
ENVIRONMENTAL RESOURCES. Those issues remaining unresolved
and/or of greater scope than covered in this EIS will also
be discussed in Chapter 6. The generic issues of particular
importance to this project are:
o The impacts on the quality and domestic use of the
groundwater system resulting from subsurface disposal
or infiltration of treated effluent.
o The biological, social and economic impacts of effluent
discharge to the Deschutes River or the North Unit
Main Canal.
o The monetary and land use cost of installation and
operation of a spray-irrigation system for year-round
effluent disposal.
Necescity/Purpose of EIS
The National Environmental Policy Act of 1969 (NEPA)
requires that all agencies of the federal government prepare
a detailed EIS on proposals for projects that may significantly
affect the quality of the human environment. NEPA requires
that agencies (in this case EPA) include in their decision-
making process all considerations of environmental aspects
of proposed artions, the environmental impacts of the
10
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proposed project arid its alternatives, and a discussion of
ways to avoid or minimize adverse effects. The EIS is to
be a "full disclosure" document and must follow specific
regulations of the EPA contained in 40 CFS, part 6,
as published in the Federal Register, Vol. 40, No. 72,
April 14, 1975.
Because the City of Bend project can be 75 percent
funded by the EPA, as part of the Construction Grants
Program authorized by the Federal Water Pollution Control
Act Amendments of 1972 (PL 92-500), it requires NEPA action.
After reviewing the amended Step II grant application from
the City of Bend for the design of a new wastewater treatment
facility, the EPA determined that significant environmental
impacts may be associates with effluent disposal and therefore
an EIS was required for the ultimate method of effluent disposal.
This decision was based on the potential of the present and
proposed means of effluent disposal to cause significant
adverse impacts on the quality of groundwater in the Bend
area.
11
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X
/•'
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Chapter 2
AFFECTED ENVIRONMENT
Introduction
This chapter presents a brief description of the project
area environment for reader orientation. More detailed
information regarding the environment directly affected by
project alternatives is given in Chapter 6 (EFFECTS OF THE
ALTERNATIVES ON ENVIRONMENTAL RESOURCES).
Location
The study area, extending from the City of Bend and its
surrounding urban area north to the Madras area, is located
in Deschutes and Jefferson Counties in west-central Oregon
(Figure 2-1). The Cascade Range and Deschutes National Forest
lie west and south of the study area. Deep canyons of the
Deschutes River and its major tributaries and level to gently
rolling high desert terrain lie to the north and east. The
Deschutes River is the major water course flowing south to
north through the study area. Site E located northeast
of Bend is the location of the wastewater treatment plant
currently under construction.
Climate
The Bend-Madras area is characterized by a semiarid
climate. Annual rainfall averages 10-12 inches with the
majority falling in winter as rain or snow. Summers are
typically hot and dry. Mean monthly temperatures range between
30°F in winter and 66°F in summer. Freezing temperatures can
occur during any month of the year.
Land Resources
Topography
The Bend-Madras study area lies within the broad, flat
plain of the DeSchutes River basin at the foot of tne eastern
slopes of the Cascade Range. Elevations vary from approximately
3,600 feet at Bend to 2,200 feet at Madras. Several volcanic
landmarks including Pilot Butte, CJ ir.e Butte, and Haystack
Butte rise up out of the gently unculating plains of the basin
to elevations exceeding 4,000 feet.
13
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FIGURE 2-1
STUDY AREA
14
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The study area is dissected by the deep canyons of the
Deschutes, Crooked and Metolius Rivers. Smaller streams of
importance in the valley are Tumalo, Willow and Trout Creeks.
Geology
Below shallow valley soils are extensive basaltic lava
flows commonly referred to as the "rimrock lavas" which form
the cliffs bordering most canyons in the study area. These
flows range from 50 to 150 feet in thickness. Lava tubas
or caves, formed when molten lava flowed out from beneath
a cooled and hardened crust, occur throughout the area.
Rimrock lava flows generally overlie a formation known
as the Madras Formation, which exceeds 700 feet in thickness
in northern portions of the study area. This formation is
composed primarily of layers of pumice, ash, conglomerate
sandstone, mudflow deposits and some interbedded lava flows.
At some locations the Madras Formation is underlain by
Columbia River Basalt. This formation is a series of basaltic
lava flows which underlie a large part of central Oregon and
Washington.
Both the Madras Formation and Columbia River Basalt
Formation overlie the John Day Formation, which is a sedimentary
unit composed chiefly of tuff.
Soils
The most common soil type in the study area is Deschutes
sandy loam, which occurs between mounds and ridges of outcropping
basalt known as scabland (USDA, 1958). Soil depths range
from several inches to 3 feet. This soil is derived from
pumice sand. Because of its coarse texture, this soil tends
to be well drained and runoff is slow.
Other common soils which occur mainly north of the Crooked
River in Jefferson County are Agency gravelly loam and loam,
Deschutes loamy sand, Era sand loam, Lamonta loam and sandy-
clay loam and Madras loam and sandy loam. Most of these soils
occur on nearly level to undulating upland plains and are
derived from sedimentary and volcanic material. Drainage is
moderate to rapid.
15
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Land Use
A primary use of land within the study area is agricultural,
with averaye farm sizes ranging from 276 to 1,344 acres (U. S.
Department of Commerce, 1977). Where soils are suitable and
irrigation water is available crops such as pasture grass,
alfalfa, wheat, peppermint and potatoes r~e grown. In areas
where cultivation i3 not economical, land is used primarily
for cattle grazing. A large portion of range land vithin the
study area is owned by the Bureau of Land Management and leased
to private parties for livestock grazinq or to other agencies,
such as the Oregon National Guard, for training purposes.
Remaining land in the study area is dominated by city and
rural centers and some state and federal recreation and park
facilities along the Deschutes River and elsewhere.
Water Resources
Surface Water Quality/Quantity
The major source of surface water in the study area is
the Deschutes River. Major tributaries such as the Crooked
and Metolius Rivers drain into Lake Billy Chinook created by
construction of Round Butte Dam on the Deschutes River east
of Madras. Smaller tributaries include Tumalo, Squaw and
Willow Creeks.
During the irrigation season, April through October,
almost the entire flow of the Deschutes River is diverted
into six irrigation canals. At the Bend diversion dam, three
canals, the Swalley, Pilot Butte and North Unit Main Canal divert
in excess of 160,000 acre-feet of water for use north of Bend and
in the Redmond and Madras areas, respectively. Upstream from the
diversion dam the three remaining canals divert over 90,000
acre-feet of water for agricultural and domestic uses east
and southeast of Bend and near Tumalo. In normal years
during the irrigation season a minimum of approximately 12-30
cubic feet per second (cfs) flows over the diversion dam to
meet water needs in the Deschutes River above Tumalo Creek
(Perry, pers. comm.). Below Tumalo Creek and upstream of
Lake Billy Chinook, flows in the Deschutes River increase to
approximately 500 cfs.
From November to March water flow over the Bend diversion
dam averages between approximately 500 and 1,000 cfs. During
this period, all canals, with the exception of the North Unit
Main Canal, have winter flows between 100 and 4, 000 acre-feet,
per month to allow domestic water users to fill their cisterns.
16
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Water quality in the Deschutes Ri"er below Bend usually
meets the state standards for dissolve * oxygen, temperature,
turbidity, pH and coliform bacteria set by the Oregon Depart-
ment of Environmental Quality for the basin (DEQ, 1977).
However, substandard conditions do occur occasionally as a
result of high tota] coliform levels from land runoff, turbidity
during periods of high flow and high temperatures during surner
low flows. Minor violations of standards for dissolved oxygen and
pH have been reported. Algal blooms in Lake Billy Chinook
are common in summer.
Water quality in the irrigation canals at their point
of diversion at Bend is the same as that in the Deschutes
River. In the North Unit Main Canal alyal and aquatic plant
blooms can occur in summer in canal segments with sluggish
water movement (Wagner, pers. comm.). Watei quality data
from this canal show that pH and coliform counts can be
seasonally high.
Groundwater Quality/Quantity
The primary source of groundwater in the Bend-Madras
area is the Madras Formation. The regional water table lies
at a depth of 500-600 feet at Bend and between 200-300 feet
below the land surface at Redmond and Madras. Perched j*
groundwater occurs within this formation at depths between'
100-200 feet at Bend and less than 20 feet below the ground
level at some locations near Madras (Sceva, 1968). Columbia
River Basalt also series as a source of groundwater wherever
it underlies the Madras Formation. An artesian groundwater
system lies below the regional water table. The John Day'
Formation has low permeability and generally does not transmit
groundwater. ,
Groundwater in the study area is believed to generally
flow in a northerly and northwesterly direction. Near Madras,
the ^Tohn Day Formation transects the Desphutes River bas:p
forming a subsurface barrier that prevents further downstream
movement of groundwater. This barrier forces all groundwater
to discharge into the river system. Over 1,400 cfs discharges
into the Crooked River Canyon and smaller amounts discharge
into the Deschutes and Metoliui. Canyons. Some of this
rising groundwater now discharges directly into Lake 3illy
Chinook.
From limited samples ot wells in tne aucdy area by Sceva
(1968) and the DEQ (unpublished data), groundwater quality
r-eLs dunking voter-standards established bv the EPA.
Groundwater in the Bend area is slightly alkaline, has a pH
of 8 and is lew in dissolved minerals. Average concentr-itions-
17
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of dissolved minerals are higher in samples taken in the Red-
mond area and highest in samples from the Madras area (Sceva,
1968). Resampling by the DEQ also confirms this trend with
increases in total dissolved solids, sodium concentration and
specific conductance being most conspicuous (Shimek, pers.
comm).
Water Supply and Beneficial Uses
Groundwater and surface water supplies in the study area
are used primarily for agricultural, domestic and recreational
purposes. Water for irrigation is supplied mainly by the
large canals diverting the Deschutes River at Bend or by
smaller diversions from the river downstream. Domestic
supplies for the City of Bend come primarily from Tumalo
Creek with two supplementary municipal wells located south-
west of the city. The City of Redmond obtains its domestic
supply from the Pilot Butte Canal and two wells in summer
and primarily from wells in winter with the Deschutes River
as a backup source. Madras obtains its water exclusively
from two wells in winter with supplementary water from the
North Unit Main Canal in summer. In rural areas domestic
supplies are obtained from private wells, irrigation canals,
springs or the Deschutes River.
Flood Hazards
Due to regulation of the Deschutes River by Crane Prairie
and Wickiup Reservoirs upstream and the presence of steep
canyon walls surrounding the river downstream from Bend, flood
hazards in the study area are minimal. All canal systems
are equipped with flow-regulating devices and spillways to
prevent flooding of surrounding land. The North Unit Main Canal
flows into Haystack Reservoir which acts as a regulating
reservo:r for the canal systen..
Air Quality
Air quality in the Bend-Madras area is excellent. In
197 6 those pollutants measured - total suspended particulates and
sulfur dioxide - complied with standards as determined by DEQ
monitoring (DEO, 197G). On winc.y days, naturally entrained
dust can increase the total suspended particulate level in
the study area. However, these levels do not exceed DEQ air
standards.
IB
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Biological Resources
Flora
The Bend-Madras area lies within the rain shadow of the
Cascade Mouncains. Summers are warm and dry with evapotrans-
piration far exceeding the precipitation in winter months.
Most of the natural vegetation in the study area reflects
these xeric conditions.
The most common and widespread plant community in the
study area is western juniper savanna. The original juniper
community consisted of an open stand of mature juniper trees
with an understory of native bunchgrasses such as bluebunch
wheatgrass, Idaho fescue, Thurber needlegrass, Sandberg blue-
grass and Indian ricegrass. Perennial forbs such as milkvetch,
buckwheat, yarrow and phlox occurred at various locations. Biy
sagebrush and bitterbrush were the dominant shrub species.
Domestic stock grazing on this plant community in the
past resulted in major vegetational changes in understory
species. Invading annuals such as cheatgrass, mustard and
Russian thistle are now dominant with native bunchgrasses
occurring at scattered locations. Rabbitbrush has increased
considerably and is the dominant shrub ir more disturbed stands.
»
Other plant communities of the study area include ponderosa
pine forest, which intergrades with juniper habitat at the
foot of the Cascade Range; riparian forest along stream beds
dominated by willows, aspen and sedges; and agricultural land
dominated by cultivated crops and irrigated pasture.
Fauna
The juniper community provides habitat for a variety of
wildlife species that have adapted to the characteristic dry
climate. Common resident species of birds include the red-
tailed hawk, black-billed magpie, California quail, American
robin and western meadowlark. Common summer residents are
the brown-headed cowbird, mourning dove and ash-throated
flycatcher. Tht Townsend's solitaire is a common winter
resident. Characteristic mammals are the Townsend ground
squirrel, Ord kangaroo rat, mountain cottontail, coyote and
mule Cc~cn reptiles include the western rattlesnake,
gopher snake, western fence lizard and side-blotched lizard.
Common species of fish found in the Deschutes River and
its tributaries are the rainbow and brown trout which are
thought to spawn in the Deschutes River above Lake Billy
Chinook (Fies, pers. comm.), brown bullhead, dolly varden
19
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and nongame species such as squawfish and bridge lip suckers.
Additional game species - kokanee and small- and largemcuth
bass - occur in Lake Billy Chinook. Haystack Reservoir
provides habitat for limited populations of rainbow trout,
kokanee, white crappie and large- and smallmouth bass
(Schwartz, pers. comm.). Most canals are piesently equipped
with fish screens at their diversion point from the river
and thus support few fish.
Rare and Endangered or Threatened Species
No rare and endangered or threatened species of fish
or wildlife are known to reside within the study area.
Archeological and Historical Resources
At the time of Euroamerican contact, the northern Paiute
Indians occupied the regions in and adjacent to the study
area. The Tenino tribe and others occupied areas to the
north and west. The first recorded exploration of the Bend
area was made in 1826 by trappers affiliated with the
Hudson Bay Company.
In the mid-1800s, pioneers began to move into Oregon.
One historical road, known as the Huntington Wagon Road,
crosses north to south through the study area. The Meeks
Wagon Train, one of the earliest wagon trains to enter central
Oregon, is believed to have used this road.
Another road of historical importance in the study area
is the Prineville-Bend Wagon Road established through con-
tinuous use by early residents of the area. The route was
the source of mail and freight into Bend for many years.
Aesthetics
Much of the land in the study area is characterized by
vast expanses of rolling, rocky, high desert terrain dissected
by deep canyons of the Deschutes River and it«; tributaries.
Numerous snowcapped peaks of the Cascade Range, most notably
the Three Sisters, Mount Washington and Mount Jefferson provide
an outstanding panoramic view from the study area. Other
attractions of the area include Lava and Pilot Buttes and the
numerous state parks such „>s Smith Rock State Park and The
Cove-Palisades. A variety of recreational opportunities
attract large numbers of both winter and summer vacationers.
20
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The aesthetic qualities of the Bend-Madras area result
primarily from the vast untouched nature of much of the
surrounding high desert terrain coupled with the scenic beauty
of the Deschutes River, noted for its numerous falls and steep
canyons, and the snowcapped peaks of the Cascade Range.
Social Environment
In 1970, the City of Bend's population was 13,710
while the urban area populanion was 19,150. By 1974, the
population had grown to 17,215 in the city and 25,690 in
the urban area. Growth within the city during this period
was attributable primarily to annexation.
Between 1962 and 1972, employment in Deschutes County
increased by approximately 72.5 percent. Although the
greatest growth in manufacturing employment occurred in the
lumber and wood products industry, which has been the
historical backbone of che local economy, the greatest total
increase in employment during this period occurred m con-
tract construction, primarily as a result the increased
employment opportunities in the manufacturing industry.
The rapid growth from 1962 to 1972 has not been sustained,
and the Bend area is currently experiencing a period of
depressed housing construction.
Another principal manufacturing industry of the study
area is livestock and dairy product processing. The recrea-
tion industry and retail trade are also significant employers.
21
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Chapter 3
WASTEWATER CONVEYANCE, TREATMENT
AND DISPOSAL SYSTEMS
Introduction
This section presents a brief summary of the existing
wastewater handling system. Also discussed is the proposed
wastewater handling system described in the City of Bend
Facility Plan prepared by STR Engineers and the Design
Definition Memoranda developed by BECON. The proposed
collection and treatment works are the facilities included
in Negative Declarations issued by EPA on April 5, 1977 and
May 3, 1978. The disposal facilities considered in this
EIS are for the treatment facility now under construction.
Historical Wastewater Handling Systems
Wastewater generated in the Bend area was historically
treated in septic tanks followed either by a drilled disposal
well or a conventional drain field. Because this area is
mantled by extensive basaltic lava flows, the pits for the
septic tanks had to be blasted using dynamite. When needed,
a disposal well was drilled adjacent to the tank and extended
to as much as 60 feet in depth. A typical disposal system
is shown in Figure 3-1. The wastewater receives a minimum
amount of treatment before the liquid is discharged to the
drilled well from which point it percolates to the groundwaters.
The number of individual disposal wells in and adjacent
to the City of Bend amounted to more than 3,000 in 1968.
By 1977, the number had risen to an estimated 6,500 wells.
A majority of the disposal wells are located east of the
Deschutes River and average about 50 feet in depth. Disposal
wells west of the Deschutes River are slightly deeper due
to the lack of surficial lava layers and the necessity
therefore of drilling to the sedimentary deposits.
The City of Bend instalxed a small collection and treatment,
system circa 1912. This system served a part of the downtown
area and some residential areas northeast of the city. Treat-
ment was by an Imhoff tank located near the present treatment
plant site. Effluent from the Imhoff tank flowed by pipe-
line and open ditch for use in irrigation and discharge to
the lava sink hole, which is now in use by the city. Until
23
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FIGURE 3-1
DIAGRAM OF A TYPICAL
DOMESTIC SEWAGE DISPOSAL SYSTEM
IN THE BEND AREA
DISPOSAL
SOURCE^ SCEVA, 1968
24
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1970 the wastewater received a minimum of treatment and no
disinfection prior to discharge. The flow was estimated at
about 0.5 million gallons per day (mgd), with a suspended
solids concentration of 50 to 200 mg/1. As a result of a
study started in 1968, the wastewater treatment plant was
constructed in 1970 and is now in use.
Existing Wastewater handling Systems
Ihe Bend urban area is served by six independent waste-
water collection and treatment systems as well as the individual
disposal systems (septic tanks) already discussed. The
largest system is owned and operated by the City of Bend
and orovides service for approximately 10 percent of the
city's population in a limited geographical area as shown
in Figure 3-2. This system, which is principally a gravity
system, terminates at the City of Bend wastewater treatment
plant. The plant is a complete mix, activated sludge plant
with a design capacity of 2.0 mgd, which was originally
sized on a service area population of 20,000 people. Sludge
digestion capacity, however, limits the plant capacity to
some value less than 2.0 mgd. The original design alsof
allowed for a future expansion to 4.0 mgd. The present)
annual average wastewater flow is about 0.5 mgd, which
indicates that significant additional population or service
connections have not been added to the system in the past
10 years.
Tne treated and disinfected effluent from the treatment
plant is discharged to the same lava sink hole that was used
before construction of the plant (sec Figure 3-3). Dis-
cussions with the treatment plant operator indicate that no
problems with regard to treated effluent disposal have! ever
occurred. Surcharges to 1 mgd. for shprt periods of ti|ne
apparently had no effect on the hydraulic capacity of (the
sink hole; however, long-term, high-volume tests have not
been performed.
Sludge generated in the treatment plant is aerobically
digested and mechanically dewatered to 12 to 14 percent solids.
The solids are trucked to a sanitary landfill site for disposal.
The treatment plant also receives and treats septic tank
sludge and privy vault wastes. Treatment of these wastes is
by course screenmo, aerobic digestion, dewatenng and
disposal of solids as.nlready described. The receiving
area for these wastes and the devatering equipment are totally
enclosed to minimize outside odor problems.
25
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FIGURE 3-2
EXISTING SEWERAGE
SYSTEMS
NIATT ftPTS
A, TREATMENT SITE
ill PUMP STATION
FORCE MAIN
GRAVITY SEWER
LIFE INSURANCE CO
RED OAKS SQUARE COMPLEX
~"V Ctl'r TREATMENT
Mb plant
I
%
I
I
I
A
A
II
ffi
*000- 40O0'
WARD CONSTRUCTION CO
PRESSURE COLLECTION St STE IS
26
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FIGURE 3-3
LAVA TUBE EFFLUENT DISPOSAL
FROM THE EXISTING
WASTEWATER TREATMENT PLANT
27
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The second largest wastewater collection and treatment
system is owned and operated by the Ward Construction Company.
This system is totally pressurized and serves a housing develop-
ment as located in Figure 3-2. Treated effluent is disposed
of by spray irrigation on a once or twice weekly basis, as
needed.
The remaining four systems are individual systems that
serve commercial activities. These small systems are septic
tanks followed by chlorination of the effluent prior to
discharge to drill holes.
Future VTastewater Handling Systems
Because of the practice of discharging wastewater
effluents, much of it essentially untreated, into deep lava
sink or drill holes, considerable concern has been expressed
about the hazards to public health through contamination of
water supplies. The significant number of water wells in
the area, as shown in Figure 3-4, and the estimated 6,500
drill holes for waste disposal scattered throughout the area
indicates the proximity of contaminating sources to drinking
water supplies. Most of the area in Figure 3-4 is considered
to have severe septic tank limitations, which would result
in poorer waste treatment prior to percolating to the ground-
water. A 1968 study conducted by the Federal Water Pollution
Control Administration (FWPCA), the predecessor to the EPA,
concluded that discharge of septic tank wastes to lava sink
or drill holes poses a potential hazard to groundwater quality.
t
i
The DEQ has subsequently promulgated regulations for the
control of waste disposal in lava sink holes (see Chapter 5).
These regulations prohibit disposal of inadequately treated
domestic wastes outside the Bend city limits after January
1975 and within the Bend urban area as of January 198 0.
Because of these regulations, it becam« imperative to dfetermine^
the optimum method for collecting, treating and disposing
of the wastes in an economical and environmentally sound
way. Also, in the WPCF discharge permit issued to the city,
DEQ required that a study be completed outlining the recom-
mended method for handling the wastes for the Bend area.
The Facilities Plan prepared by STR Engineers resulted in a
recommended plan for the collection, treatment and disposal
of wastes.
The Stevens, Thompson FnciriGers Facilities ?lsn (STP)
The STR Facilities Plan recommended a regional approach
to wastewater management in which the existing City of Bend
wastewater treatment plant would be expanded and all other
existing treatment plants would be phased out. The plan
28
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recommended by STR is described briefly in the following
paragraphs. It should be kept in mind that the STR plan
was superseded and altered by the BECON plan which changes
the treatment facility location and point of effluent disposal.
Sewage collection would typically be by conventional
gravity sewers with several pumping stations to convey the
sewage to the treatment facility.
Secondary treatment of the wastewater would have been
provided by expanding the existing activated sludge treat-
ment plant from 2.0 mgd to 6.0 mgd. Development in the Aubrey
Butte area of Bend would be served by an interim treatment
plant until the orderly expansion of the collection system
extended to this area. Waste sludge from tho treatment plant
would be anaerobically digested (primary sludge) and
aerobically digested (secondary sludge) and applied to the
land in liquid form.
The treated secondary effluent would have been used to
irrigate crops on Site C (Figure 3-5). Based on preliminary
design parameters, an estimated 600 acres would have been
required. However, during seasons when irrigation is not
feasible, treated effluent would have been discharged to the
Deschutes River downstream of the diversion dam. At these
times, water is normally not being diverted from the Deschutes
River and the dilution factor would be in the order of 1,000:1.
The other possible method of effluent disposal during inclement
weather was to the groundwater using either drill holes or
lava sink holes at the treatment plant site.
The foregoing regional plan was prepared by STR for
the city. Subsequent to the publication of the STR report,
the city elected to retain a consortium of engineers, BECON,
to implement the plan. BECON prepared a series of 10 Design
Definition Memoranda on various aspects of the project, and
these resulted in a different plan for wastewater treatment
and disposal than that described by STR. The revised regional
treatment system adopted by the City of Bend is described
below.
The Modified Facilities Plan (BECON)
The major change made to the STR regional plan was to
relocate the treatment plant to Site E approximately 4 miles
northeast of the existing site (Figure 3-5) and to abandon
the existing facilities. The reasons given for the change
in location ape: 1) the encroaching residential development
2) aesthetics, 3) lower energy consumption in the collection
system because a larger area is served by gravity, 4) concerr
30
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FIGURE 3-5
8F* BEND
j\ AIRPORT
TREATMENT PLANT LOCATIONS & PROPOSED
EFFLUENT DISPOSAL AREAS
(SITES C & E)
NEW TREATMENT PLANT
BEIND
CITY TREATMENT PLANT
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about the capacity of the lava sink hole now in use and, 5)
drill hole disposal within the Bend urban area, which has a
greater potential for contamination of local water wells
shown in Figure 3-4. The new wastewater management system
is briefly described here. The EPA prepared an environmental
assessment and, finding no significant environmental con-
sequences, issued a Negative Declaration (May 3, 197 8) for
the new wastewater treatment and sludge disposal facility.
Description of Collection, Treatment and Disposal
Facilities. Wastewater treatment would be by a conventional
activated sludge plant (secondary treatment) followed by
chlorine disinfection. Filtration using a dual-media (sand
and coal filters) would be included, if necessary, to further
reduce suspended solids thereby significantly improving
effectiveness of the disinfection process. The effluent
filtration system would be designed as a side stream operation
so Lnat it could be bypassed at times when it was not required.
The treatment schematic of the proposed plant and the
preliminary plant layout are shown in Figures 3-6 and 3-7,
respectively.
Disposal of the anaerobically digested sludge would be
by land spreading at Site E. Specially designed tank trucks
would transport and spread the sludge evenly over the disposal
area. Because the sludge would be in the 3 to 5 percent
solids range, routine discing to integrate the sludge into
the soils was not anticipated.
The projected average annual wastewater flow rate to
the plant would be as shown in Figure 3-8. At the design
capacity of 6 mgd, reached in about 1992, 2,190 million
gallons of effluent would be produced annually. The average
monthly variations in flow rate are shown in Table 3-1,
in terns of a percentage of the total annual volume and also
an estimated average daily flow during each month, based
on a 6 mgd plant capacity.
According to the city plan prepared by BECON, effluent
disposal would be to the subsurface by drill holes or lava
tube cracks to the groundwater on an interim basis. (Both
the interin and final disposition for effluent disposal will
depend upon the findings of this enviror.nertal irpact state-
ment . )
Effluent Characteristics. Effluent characteristics
refer to the probable effluent quality from the new treatment
plant. Determination of effluent quality is difficult
without the availability of detailed design criteria and
plant schematics. However,,.an indication can be obtained
from the operative records of the existing treatment plant.
32
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FIGURE 3-6
SCHEMATIC D0AGRA&3
OF PROPOSED TREATMENT PLANT
FILTRATION
PRIVY WASTES
RECEIVING
STATION
-------
FiCURC 3-7
PRELIMINARY PLAN? LAYOUT
AERATION BASINS |
SOURCE BECON, AUGUST, 1979
24
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FIGURE 3-8
PROJECTED ANNUAL AVERAGE WASTEWATER FLOWS
SEBAGE
FLOB (OGD)
YEAR
SOUaCE etc ON 0F3ISM OEFINITIOH MEMORANDUM NO T, AU0U3T 19TT
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Table 3-1
MONTHLY WASTEWATER VOLUMES AND AVEP'VGE DAILY FLOWS
(BASED ON 6 MGD ANNUAL AVERAGE DAJLY FLOW)
Average Monthly Volume Average Daily Flov;
Month1 Percent of Total Annual mgd for Month
Jan
8.05
5.7
Feb
7.36
5.8
Mar
8.22
5.8
Apr
8.05
5.9
May
8.57
6.1
June
7.97
5.8
July
9.26
6.5
Aug
9.51
6.7
Sept
8.54
6.2
Oct
8.40
5.9
Nov
7.99
5.8
Dec
8.07
5.7
'"The summer months, as used in this EIS, are through OcL'ooer arjc] the
Winter months are November through April.
36
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Also, effluent criteria can be established that will ensure
at least secondary treatment levels. These are presented
in the following discussion.
The existing wastewater treatment plant does not have
extensive records of effluent qualities. Information
available has been summarized in Table 3-2. This information
is based on data presented in the facilities plan and also
on limited analyses conducted by Century West Laboratories
and presented in the BECON Design Definition Memorandum
Number 2.
37
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Table 3-2
SUMMARY OF EFFLUENT QUALITY
(City of Bend Wastewater Treatment Plant)
Parameter Effluent Quality
(mg/1)
BOD 5-10
Boron 0.4 3
Calcium 7.0
Chloride 29.0
Chlorine Residual 1-2
COD 37.0
Conductance, MMO^- 363
Magnesium 1.9
Nitrogen
Total 13.0
Ammonia *
Nitrate *
pH, units 6.7-8.0
Phosphate *
Potassium 9.3
Sodium 52.0
Solids, Total Suspended 10-20
Solids, Total Dissolved 352
Sulphate 15
SAR, dimensionless 4.2
Bicarbonate alkalinity
as CaCo3 123
* Not measured.
38
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Chapter 4
ALTERNATIVE EFFLUENT DISPOSAL AND REUSE SYSTEMS
Introduction
Effluent disposal alternatives considered in detail in
the facility plan and additional feasible alternatives added
for consideration are reviewed in this chapter. The facilities
plan presented the alternatives considered in terms of total
systems, which therefore included wastewater collection and
treatment followed by effluent disposal methods ^ one of
several methods However, in this EIS, only effluent
disposal methods are being considered. All treatment
facilities required in addition to conventional secondary
treatment using the activated sludge process, followed
by chlorine disinfection, are considered as part of the
effluent disposal alternative. This would also include
the costs, if any, for secondary treatment facility en-
largement as a result of recycled flows that may be present
if higher levels of treatment are required. An example
of such enlargement might be the backwash solids captured
in the filters and returned to the primary sedimentation
basins.
Screening of Effluent Disposal
and Reuse Alternatives
The following are the effluent disposal options that were
initially considered in the STR Facilities Plan. The alterna-
tives to be evaluated were based on these options.
A Discharge to the Deschutes River during the winter
months (November to April) only
o Discharge to an Irrigation Canal during the summer
(May to October) only
q Land application of effluent by one of three methods
1. Spray irrigation
2. Overland flow
3. Infiltration/Percolation Ponds
o Evaporation of the effluent by discharge to storage
pords having a large surface area,
o Discharge to drill holes (relatively shallow wells)
for a regional treatment facility (in accordance with
Oregon Administrative Regulations)
e Discharge to deep well fields for regional treatment
facilities. {Wells would be totally encased and
penetrate the lower aquifer by at least 100 feet)
39
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© Reuse of effluent by two methods
1. Industrial reuse such as boiler make-up water or
cooling waters
2. Domestic or potable reuse by treating and returning
the effluent to the water supply system
Based on these seven options for effluent disposal the
facility planner selected four methods fur detailed evaluation
in coordination with the wastewater collection and treatment
alternatives. The industrial reuse option was dropped from
consideration by the facility planner, because there are no
existing or potential industrial users in the Bend area
to take the projected quantities of effluent. The domestic
reuse option was dismissed from consideration because of
the potential health risks and the high costs of treatment.
Also, the City of Bend is served by a reliable source of
high quality water. Deep well disposal and use of evaporation
ponds were dismissed in the facilities plan without detailed
explanation.
STR Proposed Alternatives
The four effluent disposal alternatives selected by
STR are described below. All four are for a regional treat-
ment facility to be located at the site of the existing
treatment plant.
Year-round Drill Hole Disposal. Under this alternative,
effluent would be discharged to drill holes on a continuous
basis. The treatment level considered was secondary, using
activated sludge followed by chemical coagulation, clari-
fication and filtration and finally, disinfection using
chlorine. Although the facilities plan indicates treatment
for nitrogen control as well, the treatment systems finally
reported and costed do not include this option.
Combination of Drill Hole and Irrigation Canal Discharge.
Effluent disposal would be to the North Unit Main Canal
during the summer months and to drill holes during the winter
months when the canal was not utilized. Treatment for dis-
charge to the irrigation canal vould be secondary treatment
followed by chlorine disinfection. Treatment for drill hole
disposal would be secondary followed by filtration and
chlorine disinfection.
Combination of Disposal to the Irrigation Canal and
Deschutes River. Secondarily treated (activated sludge)
and disinfected effluent would be discharged to the North
Unit Main Canal during the summer months and to the Deschutes
River during the winter months.
40
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Land Application of Effluent by Spray Irrigation.
Secondarily treated (activated sludge) and disinfected effluent
would be used to irrigate crops at alternate sites on a
year-round basis. For this option, three different sites
were evaluated as three separate effluent disposal alternatives.
No temporary storage reservoir is mentioned as being included
in these options. The three sites would be under control
of the city.
The purpose and intent of the initial screening process
is tc eliminate those alternatives that obviously do not
meet the cost-effectiveness requirements, in which case they
may be excessively costly or have overriding adverse environ-
mental or societal consequences. The goal of any evaluation
procedure is to identify the most environmentally, technically
and economically sound alternative. Final judgement about the
recommended alternative is almost always subjective and
based on the total cost to society. This initial screening
is based largely on monetary costs, which are relatively easy
to develop and require little site evaluation. However, any
alternative that may harbor an overriding adverse environ-
mental impact could also be eliminated unless satisfactory
mitigation measures could be taken.
The criteria used by the Facilities Planner to screpn the
effluent disposal methods included minimizing, or preferably
eliminatin9 environmental or public health hazards; reliability
and flexibility to accommodate future situations; total annual
costs, present worth costs and costs to the homeowner; and
finally site availability. Other concerns such as resource
commitments and social objectives were also considered when
screening the possible alternatives.
Fear alternatives for the disposal of treated municipal
wastewater were analyzed in detail by the facilities planner
(STR) who subsequently eliminated two methods, drill ho,'le
disposal and the combination of canal and drill hole dis-
posal, on the basis of cost and potential groundwater con-
tamination. The final recommended alternative was land
application by spray irrigation on Site C.
As previously stated in Chapter 3, the city retained
BECON to implement the facilities plan. After more detailed
site evaluation by BECON (Design Definition Memorandum #5),
Site C was found unsuitable for land application of effluent.
On the basis of relocation of the treatment plant to Site E
and further analyses of the land application alternative,
BECON recommended subsurface effluent disposal on an interim
basis, with a final disposal mecnod to by belecLeu at a
later date.
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Alternatives of effluent disposal described in the
following section are intended to be utilized as long-term
disposal options. The interim effluent disposal option chosen
for funding by EPA, in the event that the treatment plant
is ready for start-up prior to completion of this EIS,
would have to be compatible with the long-term effluent
disposal option ultimately chosen.
Proposed Effluent Disposal and Reuse Alternatives
As a result of relocation of the treatment plant to
Site E, the basis used by STR for discarding alternatives
has been altered. For example, the estimated plume of
contamination for drill hole disposal would be relocated to
the northeast and might therefore have less chance of affecting
groundwater supplies. Thus, based on disposal options
considered in the STR facilities plan, including modifications
by DECON and Joner. & Stokes Associates, Inc., there are
five basic effluent disposal options potentially suitable
for the new wastewater treatment plant. These are:
1. Subsurface disposal via drill holes or infiltration
from the surface.
2. Discharge to the Deschutes River.
3. Discharge to sealed evapotranspiration ponds.
4. Land application by spray irrigation.
5. Discharge to the North Unit Main Canal.
Subsurface Disposal
This alternative would involve year-round conveyance
of effluent by pipeline for discharge to a series of drill
holes on Site E or to infiltration ponds. Effluent discharged
to drill holes would receive secondary treatment and chlorine
disinfection followed by sand filtration. The filtration
system would be designed as a side stream operation so that
it could be bypassec" when not needed. Effluent discharged
to infiltration ponds would not receive filtration. Anti-
cipated effluent quality in terms of BOD, suspended solids
and coliform bacteria is given in Table 4-1.
For drill hole disposal, effluent would travel by
gravity flow through a pipeline to a series of drill holes
a short distance from the treatment plant. The number of
drill holes, their depth or exact location has not been
established pending detailed geological surveys recently
completed on Site E by BECON (BECON, preliminary draft,
September 1979).
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Table 4-1
ANTICIPATED EFFLUENT QUALITY FOR EACH MAJOR ALTERNATIVE1
BOD
Disposal Alternative mg/1
Subsurface:
Drill holes 10
Surface Infiltration 30
Deschutes River 10
Evapotranspiration Ponds 3 0
Land Application by
Spray Irrigation 20
North Unit Main Canal 10
Suspended
Solids
(mg/1)
10
30
10
30
kO
10
Coliform
MPN/100 ml
<10
1,000
2
1,000
20
<10
1 SOURCES:
Drill holes - See Appendix 6 - DEQ letter dated February 8, 1979.
Infiltration - estimated quality.
Deschutes River - See Appendix 4 - Minimum Design Criteria - Deschutes
River Basin
Evaporation Ponds - estimated quality.
Land Application - See Chapter 5 - current WPCF permit.
North Unit Main Canal - See Appendix 6 - DEQ letter dated February 8, 1979.
-------
Discharge of effluent to infiltration ponds would involve
gravity flow of effluent by pipeline to a series of ponds
located on Site E, or to a natural closed depression located
east of Site E (Figure 4-1) . Based on preliminary data (Cooper-
Clark & Associates, 1979), the clear water infiltration rate
in the depression was measured to be an average of 7/8 inch
per hour or 147 inches per week. However, use of wastewater
substantially reduces the amount of water that can be percolated.
For purposes of this study, a rate of 15 percent of the clear
water rate or 22 inches per week was used to determine the
land area required. (A value of 5 to 25 percent of the
clear water rate is recommended by EPA.) Local evaporation
records were used to determine the amount of evaporation
that might be experienced. The evaporation rate was found
to be negligible compared to the percolation rate. Allowing
for peak flows and reduced infiltration capecity, about
85 acres would be needed to dispose of the wastewater.
Development of the infiltration pond would require the
construction of three or more cells in the infiltration
area, which would allow maintenance of one cell while the
others were in operation. The cells would be separated by
dikes or berms. Native materials would be used to construct
the berms, which would be about 4 feet high with a crest
width of 6 feet. Soire sand and gravel would be imported
to provide a minimum percolation depth cf 3 feet. See
Appendix 1 for more detailed facilities planning on this
alternative.
Discharge to the Deschutes River
Treated wastewater under this alternative would be
pumped through a pipeline to the Deschutes River on a year-
round basis. This would be accomplished using a pumping
station and a 6.7-mile forcemain along the right-of-way of
the North Unit Main Canal. Effluent would be discharged!
downstream of the Bend diversion dam (Figure 4-2). The J
treatment system would include sand filtration and chlorjine
disinfection. Anticipated effluent quality is given in
Table 4-1.
Discharge to Sealed Evapotranspiration Ponds
Although this alternative was rejected in the STR
facilities plan, it has been reconsidered in this EIS in
modified form at the request of a local citizen, Mr. Gordon
Priday. The Priday alternative would involve construction
of a series of sealed ponds interconnected by a small canal
system. Effluent would flow by gravity through the pond
series which would extend in a northeasterly direction frcm
the wastewater treatment plant. Each pond would be constructed
and managed to establish wildlife habitat.
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FIGURE 4-1
POTENTIAL LOCATION OF INFILTRATION
POND & GRAVITY PIPELINE
-------
FIGURE 4 -2
PROPOSED EFFLUENT DISPOSAL OUTFALL
TO THE DESCHUTES RIVER
OUTFALL
PIPELINE
ROU TE
:/*
:/
:'/
;/
./If
BEND
.NEW TREATMENT
PLANT
-------
Preliminary evaluation of tbj Priday alternative revealed
that approximately 4,000 acres oJ sealed ponds having a
depth of 5 feet would be necessary to evaporate yearly
effluent production. Because of the high acreage require-
ment, the Priday alternative was modified to include peak
flow and cold season use of infiltration ponds described
under subsurface disposal.
Under this alternative, effluent would flew by gravity
pipeline to the first marshes and the infiltration pond
(Figure 4-3). Subsequent downstream flow to additional
wetlands would utilise small cement-lined canals. Wetlands
would be developed utilizing natural depressions as much as
possible for embankments. Artificial embankments, or berms,
would be constructed as described for infiltration ponds.
Marshes would have a maximum depth of 12 feet and would be
sealed with bentonite or other clay material. Aquatic
vegetation, native to the Bend area, would be planted in
each wetland area.
Marsh basins would be sized to evaporate over 3 feet
of effluent per year during the months of April through
October. Approximately 1,270 acres would be needed. Marsh
basins would evapotranspire over half of the effluent
during the year. The balance would be discharged to in-
filtration basins with an estimated 35 acres required. See
Appendix 2 for more detailed facilities planning on this
alternative.
Land Application by Spray Irrigation
Under this alternative effluent would receive secondary
treatment, then would be pumped to either center-pivot or
fixed-head (solid-set) irrigation units for spraying onto
the land. Anticipated effluent quality is given in Table 4-1.
The sprinkler system would be designed to work around
rock outcrops, thereby eliminating the expense of rock removal.
The disposal system also would include storage reservoirs
to hold the effluent during periods of freezing weather when
the irrigation system could not be operated.
Spray irrigation disposal of project effluent would
ultimately require 1,350 acres to accommodate a treatment
plant capacity of 6 ragd. Site E (3,000 acres) contains
approximately 800 acres of suitable land for irrigation.
The remaining 550 acres would be developed on Site F (2,560
acres) as needed (Figure 4-4). Four 100 acre-foot reservoirs
would be needed for effluent storage during periods of freezing
temperatures.
47
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FIGURE 4-3
POTENTIAL LOCATION OF PIPELINE/
CANAL ROUTE & PONDED AREAS
-------
FIGURE 4-4
POTENTIAL SITES FOR LAND APPLICATION
BY SPRAY IRRIGATION
A
u
A
MO^'L s'
J
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Site loading factors, or quantities of effluent to be
applied to the soil, were determined by BECON in Design
Definition Memorandum #5 on the basis of hydraulic and
nutrient loading rates. Other constraints considered were
metal and salt quantities, crop requirements for moisture
and climatic restraints. The basic site-loading factor
determined from these studies was a hydraulic loading rate
of 5 acre-feet per acre-year. At this loading rate, no
other constraints were found to limit effluent application
on a suitable site.
Effluent would be applied to a cover crop such as reed
canary grass, fescue, orchard grass, meadow foxtail or a
combination of these. No final selection of crops has been
made as to the most suitable with respect to maximum water
consumption and nitrogen use. The crop would be harvested
and marketed.
Discharge to the North Unit Main Canal
The alternative i:. based on year-round discharge of
treated wastewater to the irrigation canal. Due to the
location of the treatment plant, which is currently under
construction and the principal use of canal water for
irrigation, the North Unit Main Canal was considered moie
appropriate for effluent disposal than other canal systems
in the Bend area. Effluent would undergo secondary treatment
followed by chlorine disinlection and filtration prior to
discharge. Effluent qualify would be as given in Table 4-1.
The effluent would be pumped through a short forcemain
and discharged directly to the canal. The flow rate would
average approximately 9 cubic feet per second (cfs).
Because the North Unit Main Canal operates only duriny
the irrigation season, roughly April through October,
modifications to year-round canal discharge are included
under this alternative to avoid discharging effluent to an
empty canal. That is, effluent would be discharged to the
canal during the irrigation season only, and one of the
following alternatives would be utilized for effluent disposal
from approximately November through March.
1. Discharge; to the subsurface (i.e., drjll holes
or infiltration).
2. Discharge to the Deschutes River.
3. Discharge to storage reservoirs.
The method and location of discharge to drill holes,
the Deschutes River and infiltration ponds would be the sane
as previously discussed under each major alternative. However,
50
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because effluent would be discharged only 5 1/2 to 6 months
of the year to these locations, the annual effluent discharge
would be 870 million gallons, with the remaining 1,320 million
gallons discharged to the canal during the irrigation season.
Infiltration pond size would be approximately 35 acres.
Discharge to storage reservoirs would involve construction
of sealed reservoirs near the treatment plant site. The
storage system would consist of several smaller storage cells
to afford operational flexibility and easier management of
the system. Effluent stored in winter would be discharged
to the canal during the next irrigation season at a constant
rate sufficient to empty all lagoons by the end of the
irrigation season. The delivery system would consist of a
forcemain and effluent pumping station. Although some
evaporation would occur from the storage reservoirs,
effluert flows to the canal would range from 15 to 20 cfs,
depending on the month and the rate of pumping from storage.
No-Action Alternative
The EPA regulations for preparation of an EIS require
that a "no action" alternative also be evaluated and compared
to the alternatives of effluent disposal. The no-action
alternative for the City of Bend would entail continuation
of the existing wastewater treatment and disposal systems
described in Chapter 3. These are discharge of secondarily
treated effluent from the existing treatment plant through
a lava tube and discharge of inadequately treated wastes to
the subsurface from over 6,000 individual disposal wells.
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Chapter 5
LEGAL, POLICY AND INSTITUTIONAL CONSTRAINTS
This section provides a checklist of laws and regulations
of various governmental agencies that have either regulatory
or planning responsibility affecting implementation of proposed
methods of effluent disposal. Those laws or policies which
may act as constraints or guidelines at the federal, state,
and local level for wastewater disposal m Bend are described.
Environmental Requirements (General)
The following regulations govern preparation of EISs:
National Environmental Policy Act
The National Environmental Policy Act of 1969 (NEPA)
establishes policy regarding environmental quality. NEPA
requires that all agencies of the Tederal government prepare
detailed EISs on proposals for projects that may significantly
affect the quality of the human environment. NEPA requires
that agencies include in their decision-making process an
appropriate and careful consideration of all environmental
aspects of proposed actions, an explanation of potential
environmental effects of proposed actions and their alternatives
for public understanding, a discussion of ways to avoid or
minimize adverse affects of proposed actions, and a discussion
of how to restore and enhance environmental quality. The
Act is implemented through the Council on Environmental
Quality (CEC)•
Council on Environmental Quality (CEQ)
The CEQ is responsible for coordinating development of
the impact statement process. Their published regulations
and guidelines (40 CFR 6) apply to the obligation of all
federal agencies under Section 102 (2) (c) of NEPA. Final
regulations are in the Federal Register, November 29, 1978.
Under these guidelines each federal agency is required to
adopt procedures for the implementation of the Act and CEQ
guidelines. The EPA has proposed rules for implementing
procedures on NEPA in the Federal Register, June 18, li<79.
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CPA Cost-Cffeet¦'veness Analysis Guidelines
The EPA Cost-Effectiveness Analysis Guidelines (197 4)
provide a uniform method for computing and comparing the costs
of wastewater treatment alternatives. The guidelines delineate
the planning period over which the alternatives should be
evaluated, the elements of cost that should be included,
the interest rate that must be used, guidance on the service
life of various types of facilities, and the salvage value
that should be used for proposed projects.
Cultural Resources and Land Use Constraints
Because effluent disposal facilities will occur in
part or wholly on federal land, the following rules and
regulations governing preservation of cultural resources and
use of federal land are applicable.
American Antiquities Act of 1906
This Act establishes protection over any "historical
or prehistoric ruin or monument, or any object of antiquity
situated on government lands ..." A permit is required fox
their removal.
National Historic Preservation Act of 1966
This Act authorizes the Secretary of the Interior ho
expand and maintain a National Register and establish an
advisory council given the responsibility to comment on the
effect of federal undertakings on National Register properties.
National Environmental Policy Act
Title I, Section 101(b) of NEPA charges the federal
government with "the continuing responsibility ... to use
all practicable means ... to preserve important historic,
cultural and natural aspects of our national heritage . . ."
Executive Order 11593
Executive Order 11593 (1971) entitled Protection and
Enhancement of the Cultural Environment directs federal agencies
to survey all lands and nominate properties to the National
Register.
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Recreation and Public Purposes Act of 3 926
This Act authorizes the Secretary of the Interior, under
specified conditions, to sell or lease National Resource
Lands (public domain) to state and local governments for public
and quasi-public purposes. Relevant provisions of the Act
follow:
1. A limit to 6,400 acres exists on acreage that can
be leased or purchased annually by political
subdivisions of the state.
2. The BLM may dispose of no more land than is reasonably
necessary for efficient operation of the projects
described in the development plan submitted by an
applicant.
3. The BLM must conduct a field examination e.nd other
investigations to gather information and data on
the environmental considerations and proper classi-
fication of the land proposed for disposal. Public
meetings must be held for any disposal over 640
acres.
Federal Land Policy and Management Act of 1976
Title IV, Section 402 (grazing leases and permits)
states:
"Whenever a permit or lease for grazing domestic live-
stock is canceled in whole or in part, in order to devote '
the lands covered by the permit or lease to another public
purpose, including disposal, trie permittee or lesser (sic),shall
receive from the United States a reasonable compensation 1
for the adjusted value ... of his interest in authorized
permanent improvements placed or constructed by the permittee
or lessee on lands covered by such permit or lease . . .
Except in cases of emergency, no permit or lease shall be
canceled urder this sutsocti >r. without two years' prior
notice."
The North Unit Main Canal is owned by the Bureau of
Reclamation and operated by the North Unit Irrigation District.
Under the following contract, there are stipulations governing
operation of the canal system.
55
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Amendatory Repayment Contract - U. S. Department of the
InteriorBux-oau of Reclamation, February 13, 19~54
As interpreted by the Bureau of Reclamation, Article 29(b)
implies that the District and the Bureau have the right to run
water in the North Unit Main Canal system only during the
irrigation season (Williams, pers. comm.).
Several effluent disposal alternatives, if chosen,
would be constructed on BLM land in or near Site E, which
is located directly north of the Bend Airport. The airport,
which serves primarily propellor aircraft and some private
turbo jets, is planned for expansion. The following Federal
Aviation Administration (FAA) Regulations are applicable to
the location, in relation to airports, of effluent disposal
facilities involving use of open water areas.
Federal Aviation Administration Order 5200.5
"5. CRITERIA. Sanitary landfills [or any other structure
that attracts bird life (pers. comm. Ossenkop]), will be
considered as an incompatible use if located within areas
established for the airport through the application of
the following criteria:
a. Landfills located within 10,000 feet of any runway used
or planned to be used by turbojet aircraft ..."
Water Pollution Control
The following federal and state laws governing water
pollution control are applicable to all alternatives of
effluent disposal.
Federal Water Pollution Control Act Amendments of 1972
and 1977
This Act establishes a national goal to eliminate the
discharge of pollutants into navigable waters by 1985 and an
interim goal of water quality which provides for the protection
and propagation of fish and wildlife and provides for recreation
in and on the water by July 1, 198 3. National policies
established by the Art call for federal assistance for construction
of publicly-owned waste treatment works and preparation and
implementation of area-wide waste treatment managment planning
processes by each state. The EPA is designated as the
administrator of the Act.
Under Section 102(a) of the Federal Water Pollution
Control Act the EPA, in cooperation with state and local agencies,
is responsible for developing . . .
56
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" . . . comprehensive programs for preventing, reducing,
or eliirdnatirig the pollution of the navigable waters and
ground waters and improving the sanitary condition of surface
and underground vaters. In development of such ccmprehensive
programs due regard shall be given to the inprovements which
are necessary to conserve such waters for the protection and
propagation of fish and aquatic life and wildlife, recreational
purposes, and the withdrawal of such waters for public water
supply, agricultural, industrial, and other purposes."
Safe Drinking Water Act
The Safe Drinking Water Act of 1974 (Public Law 93-523)
directs the EPA to establish minimum national drinking water
standards. These standards set limits on levels of specific
contaminants in public water systems which, in the judgement
of the EPA, may have an adverse effect on the health of
persons.
The EPA has established maximum contaminant levels for
various inorganic and organic chemicals, bacteria, radio-
activity and turbidity (Appendix 3).
Under Part C of the Act, entitled Protection of Under-
ground Sources of Drinking Water, the EPA has developed
regulations governing underground injection of wastes (Section
1421). Section 1422 of the Act requires implementation of an
underground injection control (UIC) program, which meets the
requirements of regulations in effect under Section 1421, in
states which, in the judgement of the EPA, need a 'JIC program
to assure that underground injection will not endanger
drinking water sources. The State of Oregon has recently
been included on the list of states needing UIC programs
(Federal Register, June 19, 1979) and therefore muse develop
a program meeting EPA requirements. The EPA has proposed
regulations for UIC programs (Federal Register, April 20 and
June 14, 1979). Under these proposed regulations, subsurface
disposal via drill holes, as described m Chapter 4, would
potentially be classified as a Class V well which includes
municipal effluent disposal wells that discharge wastes
above all underground sources of drinking water (Sceva,
pers. comm.). A particular Class V well would be subject
to regulation if it cculd be proven that the waste discharge
was presenting a significant risk to the health of persons.
57
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Water Supply Systems - Oregon Revised Statutes 448.205 to
448.325
Under these statutes the Oregon State Health Division
has jurisdiction over all domestic water supply sources and
community and public water supply systems. The division is
in charge o£ examining water sources "periodically to ascertain
whether the sources are adapted for use as water supplies
for drinking and other household uses, or are in a condition
likely to cause a public health hazard."
The division is required to prescribe minimum standards
for the biological, chemical, radiological and physical
quality of water supplied for water supply systems. State
water quality standards are given in Appendix 4.
Water Pollution Control - Oregon Revised Statutes 468.7QQ
to 468.775
Authority over water pollution control is given to the
Oregon Department of Environmental Quality (DEQ) and Environ-
mental Quality Commission under these statutes. The commission
by rule may establish effluent limitations as defined in
Section 502 of the Federal Water Pollution Control Act and
other minimum regulations for disposal of wastes. The commission
may also establish standards of water quality and purit^ for
all river basins in the state.
Groundwater Act of 1955 - Oregon Revised Statutes 537.505 to
537.795
This Act directs the State Water Resources Department
in conjunction with other agencies to assure "adequate ^nd
safe supplies of groundwater for human consumption . . j. and
prevent or control within practicable limits the impaiirment
o$ natural quality, of groundwater by pollution ..."
Construction and Use of Vaste Di^n-bnl Kells - Oregon
Administrative Rules 340--4-005 to 34 0—4^-045
In 1969 the State of Oreqon adopted regulations designed
to restrict, regulate or prohibit future construction and use
of waste disposal wells in the stazo, particularly in lava
terrain of central Oregon, because sucr. practices constituted
"a threat of serious, detnnental and irreversible pollution
of valuable groundwater--resources and a threat to public
health ..." Extracts, cf relevant sections appear in
Appendix 5.
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Oregon Revised Statute 690-62-02b adopted in 1977 by
the State Water Resource Department states that "no well shall
be used as a disposal pit for sewage, industrial waste, or
other materials that could pollute the ground water supply."
Uater Quality Standards and Effluent Disposal
Pemit Requirements
Point source discharge of wastewater effluent to surface
waters receives a Federal National Pollutant Discharge
Elimination System (NPDES) permit which prescribes general
and special conditions, such as allowable mixing zones ar.d
monitoring programs, governing the permitted discharge. All
other nethods of wastewater disposal not involving direct
discharge to surface waters of the state come under the
jurisdiction of the Oregon DEQ and are issued Water Pollution
Control Facilities (WPCF) permits.
Surface Water Discharge
Deschutes River. Specific water quality standards have
been adopted by the State Dopartrcit of Environmental Quality
for the Deschutes River basin to protect a variety of benefice!
uses including domestic water supplies, irrigation, anadrorojs
fish passaqe, rearing and spawning, recreation, and aesthetic
quality. These standards are outlined in Appendix 6.
The Department of Environmental Quality has also esteh' ishe-i
minimum design criteria for discharge of any waste from any
new or modified treatment facility to waters of the Deschutes
River basin, subject to the implementation program of Section
3-10-J1-120 (requires issuance of a permit from the DEQ prior
to discharge to public waters). Relevant criteria from
Section 340--il-575 are also included in Appendix 6.
North Unit Main Canal. The North Unit Irrigation District
NP^iJS waste discharge peinut was revoked in March of 1978
(.V^conaix 1) . The Clean Water Act of 1977, which amended
the federal Wai"er Pol lution Conlrol Act, removed irrigation
return flows from the point sorrce pollufon category and
identified tnem as nonpont souica pollutants. Therefore,
a permit is no longer required lor the District's irrigation
return flow..
59
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Minimum design criteria (OAR 340-41-575) for waste
discharge to the North Unit Main Canal would bo 20 mg/1 BOD
and SS on an interim basis and 10 mcj/1 BOD and SS for long-term
disposal (see DEQ letter, Appendix 8). ORS 449.550-449.565
(Deschutes River Pollution Abatement) prohibiting discharge
of sewage effluent to irrigation canals in the Deschutes
Basin was repealed in 1973.
Subsurface Discharge
Specific regulations regarding the quality of effluent
discharged to lava tubes or drill holes are contained in
WPCF permits issued by the DEQ. Current limitations on
subsurface water disposal contained in the City of Bend KPCF
permit (Appendix 9) are:
"Prior to disposal of the waste water it shall receive at
least the following treatment:
a. Monthly average effluent flow shall not exceed 37S5 m^/d
(1.0 MS)).
b. BOD and TSS shall not exceed a monthly average of 20 nig/1
or 76 kg/day (166.8 UVday); weekly average of 30 mg/1
or 113 ko/day (250 lb/day); and a daily maxiiarn of 170
kg (375 lb).
c. Effluent discharged to the sink liole shall receive dis-
infection sufficient to reduce fecal coliform bacteria
to a monthly average of 200 per 100 nl or a waekly
average of no more than 400 per 100 ml.
d. The effluent pH shall be within the range 6.0-9.0. "
Land Application by Spray Irrigation
Reuse of treated effluent is encouraged by both state and
federal agencies. Section 201 (d) of the Federal Water Pollution
Control Act Amendments states ''the Administrator (EPA) shall
encourage waste treatment management which results in the
construction of revenue-producing facilities providing for . . .
the recycling of potential sewage pollutants throuqh the
production of agriculture, silviculture, or aquaculture pro-
ducts...". In addition, the EPA Policy on Land Treatment
of Municipal Wastewater (D. Costle, letter to regional admin-
istrators, October 3, 1^77) states that "particular attention
should be given to wastewater treatment processes which renovate
and reuse wastewater as well as recycle the oroanic matter
and nutrients m a beneficial manner". Chapter 340-41-026
of the Oregon Administrative RuJes states that it is the
policy of the State of Oregon to give highest priority to
alternatives of waste disposal which utilize reuse or disposal
with no discharge to public waters.
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The DEQ has prepared a proposed statewide policy for land
irrigation and disposal of treated sewage effluent. These
standards were adopted to act as guides in reviewing proposals
for such use and disposal. Excerpts of relevant sections
follow:
"IV. Application in Areas Where Public Contact is Restricted
1. Surface or spray irrigation of crops not for human consumption.
Treated sewage effluent used for either surface
or spray irrigation of alfalfa, stubble land,
timber land, grass seed crops or other types
of fodder crops shall at all times be an
adequately disinfected secondary effluent.
The sewage effluent shall be considered
adequately disinfected if the average coli-
form bacteria count does not exceed 1,000
per 100 milliliters with not more than 20%
of the sa-rples exceeding 2,500 per 100
milliliters.
V. Degree of Treatment Required
2. Any sewage treatment plan where it is desired or
intended to produce treated sewage effluent for
the purpose of land irrigation under Section IV-1
above, must at all times during irrigation:
A. Produce an effluent where the:
(1) Biochemical oxygen demand does not exceed
30 ng/l.
(2) Suspended solids do not exceed 30 mg/1.
B. Provide an actual chlorine contact time as
determined by dye test of at least 60 minutes
at average design flow after thorough mixing.
C. Provide a chlorine residual of at least 2.0
mg/1.
VI. Sampling, 'lasting, and Reporting
1. Land irrigation.
Ml tests required by the waste discharge
permit shall be coruucted; and durinq the
period when treated sewace effluent is being
used for land irrigation, effluent samples
for bacteriological analyses shall be collected
at least three tiros weekly on alternate days
of the wee1: and shall be analyzed using an
approved laboratory method for coliform
bacteria count."
61
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Additional and more restrictive regulations on spray
irrigation for the City of Bend are contained in the current
WPCF permit.
Sound irrigation practices must be followed to prevent:
"a. Prolonged ponding of waste on the ground surface;
b. Surface runoff or subsurface drainage through drainage
tile;
c. The creation of odors, fly and mosquito breeding and
other nuisance conditions; and
d. The overloading of land with nutrients or organics.
Unless approved otherwise in writing by the Department,
a deep-rooted, permanent grass cover shall be maintained on
the land disposal area at all times and periodically cut to
maintain it in the growth cycle to insure maximum infiltration
and evapo-transpiration rate during the disposal season."
Effluent must receive at least the following treatment:
"a. BOD and TSS shall not exceed a monthly average of 20 mg/1
or 76 kg/day (166.8 lb/day); weekly average of 30 mg/1 or
113 kg/day (250 lb/day); and a daily maximum of 170 kg
(375 lb).
b. Effluent disposed of on land shall receive disinfection
sufficient to reduce fccal coliform bacteria to a monthly
average of no more than 20 per 100 ml. In no case shall
the chlorine residual be permitted to drop below 1.0 mg/1.
c. Hie effluent pH shall be within the range 6.0-9.0".
£2
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Chapter 6
EFFECTS OF THE ALTERNATIVES ON
ENVIRONMENTAL RESOURCES
Introduction
Central to the evaluation of viable wastewater disposal
alternatives are the environmental impacts that result. In
this chapter, both the beneficial and adverse impacts are
identified and evaluated. Mitigation measures for adverse
impacts are also discussed with primary attention given to
those resources most evidently affected by the proposed
actions.
Short-Term Impacts
Short-term impacts, as the name implies, have a short
but finite period of impact, usually from the start until
completion of project construction. Such impacts usually
can be effectively mitigated. Common short-term impacts and
their mitigation measures are presented in Table 6-1. Most
of the short-term impacts presented are considered to be
relatively minor or moderate in effect. A discussion of
those short-term impacts considered to be most significant
follows.
Major adverse short-term impacts would be associated
with land application by spray irrigation. Construction of
a spray disposal system would initially require conversion
of 8CJ0 acres of native vegetation on Site E to cover crops
such as fescue, orchard grass and meadow foxtail. An addi-
tional 550 acres on Site F would be converted for spray
irrigation of effluent as the treatment plant is expanded to
a capacity of 6 mgd.
A temporary loss of vegetation of this magnitude could
significantly increase soil erosion. Soils in the Bend area
are finely textured and when exposed are subject to severe
erosion primarily by wind. Water erosion on Sites E and F
would be minimal cue to low rainfall ana gentle slopes.
During construction of the spray disposal system, wind
erosion of soils could ue controlled by sprinkling water or
wetting chemicals on the soil surfaca.
63
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Table 6-1
SHORT-TERM IYPACTS
BEND EFFLUENT DISPOSAL ALTERNATIVES
The direct short-tern impacts of this project are related to construction activities. Mary are relatively
niror in effect and magnitude and in most cases the adverse impact can be effectively mitigated. The ir-.pacts
corsidered, our judgement of the relative level of effect and mitigation measures are given in the following
-.atnx.
Disposal Alternatives'
Short-term Impacts'
NO
Action
Recommended Mitigation
Measures
Te-.porary loss of
vegetation
Replant after construction
or encourage regrowth of
natural vegetation.
Vegetation adjacent to
pipelines should be
flagged or fenced to keep
vegetation destruction to
a minimum.
Disr iptioT to 1 2 J 2 2 1 0 Vegetation removal should
wildlife ' occur during late sur.-ier
or fall when nesting
birds are not present.
'fater quality 112 112 0 Construction acti"iti»s
degradation in streans or canals
should be limited to low
flow or no flow periods.
Care should be taken r.ot
to discharge petroleum or
other pollutants into
streams.
Increased turbidity 1
di5t'jrb5ncc to fish
life
0 2 0 0 1 0
Constuction should occur
djring period of lowest
flow and f.st.
l.itions wojld be least
off ected.
Increased potential 13 2 3 3 2 0 Soil should be netted
soil erosiOT ~nd dust down during construction.
After construction o.posed
soil areas should be re-
sccded -fith rati\o
species cr cover crop"; as
c.oon as possible.
-------
Short-terr iTpacts'
Disposal Alternatives'
1 -.o
a b 2 3 4 5 Action
Reeomendod Mitigation
Measures
Construction-related 1
traf fic
2 2 2 2 2 0
Construction should occur,
if possible, during the
fall period when traffic
voluires are lower.
Disr-ption of through 0
aid local traffic
0 2 0 0 1 0
Barricades and flagmen
should be posted as
necessary to guide
traffic through con-
struction zones.
Residents in area should
be notified as to
location, nature, and
duration of construction.
Safety hazards 1
12 111 0
All open trenches should
bo covered or fenced at
the end of each work day.
All construction equip-
ment should be sccurec.
against unauthorized use.
Aerial pollutants
f,
All vehicles and equip-
ment should bo fi cd
v.ith appropriate pollx1-
tion control devices that
arc properly maintained*
(Burning of veactatiun
should bo confined to
periods of favorable
^eteorolo i jca1 conditions).
Visual lr.pact of
construction 1
12 111 0
Equipment should be stored
in a designated area.
All litter should be
removed.
Spoil disnosal 1
2 2 3 2 2 0
Wherever possible, dis-
posal of spoil rrateriil
from pipeline routes or
other construction area®;
should be coordinated with
ether onqoiry projects
rcedxrrj till Tutorial.
-------
Short-term Impacts'
Disposal Alternatives'
1 No Recommended Mitigation
a b 2 3 4 5 fiction Measures
Stockpiling and 1
storage of spoil
2 2 3 2 2 0
All spoil material not
needed for backfilling
should be removed from
pipeline routes or con-
struction areas or spread
over the surface and
reseeded if possible.
Increased noise 1
2 2 2 2 2 0
All equipnent should have
mufflers, properly in-
stalled and maintained.
Construction activities
should be limited to day-
light hours.
Enploy-ient + + + + + + 0 No le necessary.
Ecoro-nic activity + + + + + + 0 None necessary.
'Degree of Impact;
0 No change from present
1 Minor adverse iirpact
2 ['operate adverse impact
3 I'jior adverse impact
+ Beneficial impact
2A1 ternativc:
1 Subsurface Discharge: a) drill hole; b) infiltration
2 Di,:c1i;r(,c to the Deschutes Piver
3 D: sch.ito ccalcd evapotrar.spiration ponds (including peak flow and cold season use
of infiltration banins)
4 Lara application by spray irrigation
5 Dischorc-e to the North l>mt "am Caral (including options for winter discharge)
-------
For storage of effluent whenever spraying is not possible,
four 100-acre-foot reservoirs would be constructed on Site E.
Reservoir construction would require removal of additional
acres of native vegetation. Unless natural land depressions
are used as reservoir sites, a significant amount of soil and
rock would be excavated from the site and used in dike con-
struction or removed. During construction, a significant
amount of soil erosion by wind could occur. Those techniques
mentioned above for controlling soil erosion and dust could
be utilized here.
Construction of infiltration and sealed evapotranspiration
pond alternatives would require removal of 85 and 1,305 acres
of native vegetation, respectively. Construction operations
would require extensive soil excavation and rock removal where
natural land depressions are not used. During this time, loss
of vegetation and soil disturbance could result in severe wind
erosion of the remaining soil. Mitigation measures mentioned
above for construction of a spray irrigation system would also
aid in alleviating soil erosion problems during construction
of evapotranspiration and/or infiltration ponds.
Primary and Secondary Long-Term Impacts
Primary impacts result directly from the construction,
location and/or operation of advanced wastewater treatment
(AWT) and effluent disposal facilities. These impacts tend
to be on or near a facilities site or pipeline routs or in the
area of effluent disposal. Secondary impacts refer to induced
effects of the project. These impacts may occur in all the
areas in which primiry project impacts are anticipated such as
land use, economics, and the natural environment. They are the
outcome of changes in the pattern of land and resource use for
which the project can be seen as the sole or contributing cause.
Secondary impacts are indirect in nature and, therefore, are
generally more difficult to identify and quantify than are
primary impacts. Primary and secondary long-term impacts
generally remain in force for the life of the project (20 years),
or longer.
The following section will address those primary and
secondary long-term environmental impacts associated with
alternative methods of effluent disposal and AWT treatment
as well as those associated with the no-action alternative.
Impacts will be discussed by resource categories such as
surface water, groundwater, and fisheries. Any additional
information about these resources, deemed necessary to dis-
cussing impacts, will be included under the appropriate
resource category. Impacts associated with construction of
67
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the new wastewater treatment facility on Site E are similar
for all effluent disposal alternatives considered and were
evaluated in the EPA Negative Declaration issued in April 1978.
Reliability
Wastewater Treatment Plant. Central to the discussion
of impacts of all disposal alternatives is the reliability
of the future treatment facility in meeting secondary treat-
ment standards. A recent EPA report indicated that approxi-
mately 55 percent of the nation's treatment facilities did
not meet secondary treatment standards as defined by the EPA.
In a separate report prepared for the EPA, 30 treatment plants
were evaluated in detail with the following results:
o 23 percent met secondary treatment standards
o 54 percent did not meet secondary treatment standards
because of operation and maintenance deficiencies
o 23 percent did not meet secondary treatment standards
because of design deficiencies
Therefore, although biological secondary treatment is
a common and well established treatment process, mdny problems
are prevalent which result in below-standard effluent quality.
Activated sludge treatment systems are not difficult to
operate, but they do require that at least the plant superin-
tendent be a licensed operator who has had several years
training on activated sludge plants. Theie are many methods
that have been used successfully to operate activated sludge
plants; however, descriptions of these arc beyond the scope
of this EIS. Based on the same 30-plant evaluation, the top
ten reasons for not meeting standards were causediby bhe
following: the first three were^operational and pf the next
seven, six were caused by desigir deficiencies. T^ie proper
and efficient operation of the activated sludge plant is
critical to the effectiveness of the effluent filtration
process and subsequent chlormation process.
Therefore, in evaluating the environmental impacts of
each disposal alternative the possibility of treatrcnt plant
failure will enter into these analyses. However, will
assumed that the future treatment plant will meet secondary
treatment standards most of the time.
68
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Groundwater
Groundwater resources of the Bend area have been explored
to only a limited extent by well development and use, and
by professional investigators. Therefore, groundwater reservoir
characteristics and dynamics have had to be inferred to a
large degree. Drilling of new wells in recent years has
added to the understanding of local groundwater. Detailed
studies of the geology and groundwater below Site E have
recently been completed (BECON, preliminary draft, September
1979). Final results of these studies, however, are not
yet available.
Nevertheless, the state of knowledge in the overall
region is adequate to allow a general assessment of conditions
and to at least visualize the range of potential hydrogeologic
occurrence beneath and adjacent to the project site. Whereas
probable site groundwater conditions can be projected from
data in other localities, recently completed site explorations
will aid further in determining actual conditions and how
possible disposal plans would affect the groundwater environment.
Hydrogeology. Most of the Bend project site area is
underlain by basaltic lava flows to usual depths of 100 to
150 feet. These rocks, the so-called rimrock lavas, are
characteristically jointed and fractured and contain occasional
lava tubes, or caves. Consequently, they are substantially
permeable and capable of transmitting fluids readily. It is
into this zone that private septic tanks, as well as the City
of Bend treatment plant, discharge sewage effluent.
Beneath this unit the Deschutes formation (formerly
labelled the Madras formation) extends to depths of at leest
600 to 700 feet. This formation is composed primarily of
sedimentary materials, including sandstone, conglomerate,
ash, cinders, sand and gravel and some clay. Lava flows are
commonly interspersed with the sediments. Most area wells
tap a deep aquifer zone and water table in ^he lower portion
of this sequence at depths of 500 to 600 feet. This aquifer
is not prolific and well yields are commonly limited to 2 to
10 gallons per minute. Weak-perched water bodies are occasionally
encountered by wells at shallower depths which furnish small
amounts of water in places. But frequently no usable amounts
of groundwater are found above the regional water table. A
few deep wells have been reported as dry holes.
A still deeper aquifer exists below this general acea,
tapped by several wells. Although very little data are
available, it is believed to be of widespread regional extent
and the principal groundwater resource in the region. The
best indication of the aquifer is the recent U. S. Forest
Service well at the Bend Pine Nursery, some 2 miles southwest
of the project site boundary and about 3 miles f~cm the new
69
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treatment plant locality. This i.ull encountered an apparent
weak-perched water zone around 500 feet. An aquifer zone
with an estimated 100 gpm productivity potential was penetracec".
at an approximate depth of 94 3 feet under a small amount of
artesian head. Then at 900 feet the well tapped a prolific
aquifer, consisting c" fine gravelly sand under a head of
almost 300 feet. The completed well, open to both of these
lower zones, tested *t 1,500 gpm with less than a foot of
drawdown and is now operational at a yield of 1,000 gpm.
Static water level in the well was reported at a depth of
702 feet.
This deep aquifer may directly overlie the Columbia
River basalt s'equence, comprising either an interformational
unit, or possibly the lowermost member of the Deschutes
formation. Several other wells north and northeast of 9end
exceed 700 feet in depth; however, they do not penetrate
this deeper highly productive zone.
Several miles away, the two City of Bend supply wells
encountered, large aquifer sources 3t depths.in the range of
700 to anout 850 feet. Individual veil production capacity
has been rated up to 2,000 gpm. The distance of this locality
from the Forest Service nursery well makes direct correlation
dubious. Nevertheless, this deep production zone is probably
hydrologically correlative with that of the Forest Service
well and extends throughout a very wide region.
Groundwater Occurrence and Movement. Essentially,
groundwater occurrence here can be categorized as consisting
of a deep regional aquifer, as previously recognized, rancor
localized perched bodies above it, and a deeper, highly
productive aquifer under considerable artesian head.
Perched zones are often found in cinder or sand beds,
but also in lavas and sandstones as well. Individual bodies
of this type are not usually extensive, occurring randomly
anc. erratically. Perched water tables are ordinarily shallow,
ranging from 20 to several hundred feet in depth. Where
tapped by wells, productivity vanes from perhaps 1/2 to
several gallons per minute. Perched water tables may slope
in any direction depending on local stratification and
recharge buildup, which diverts groundwater accordingly.
Where gradients permit, trapped water flows beyond the edge
of the supporting barrier layer and thence follows a downward
path to the next obstruction at a lower depth. Whereps
the ultimate destination of water moving downward is theoreti-
cally the deep regional aquifer zone tapped by most wells,
the variety of stratification and rock materials in the
appreciabx - depth interval to be traversed make such a course
devious. Ti^nsit times cannot be estimated at preser.u. In
some areas they could be relatively rapid, but rates are
undoubtedly extremely slow jn others.
70
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The zone heretofore referred to as the regional aquifer
has usually been encountered between cepths of 600 and 700
feet. The piezometnc levols m such wells run 500 to 600
feet deop, often within 50 feet of the well bottom. In
sone cases, there is a rrmor rise m water level after the
aquifer is first penetrated but such apparent artesian effects
may be only localized.
Similar to perch&d bodies, this water is reported to occur
in sands, gravels, lavas, pumice, sandstone, cinders :>rd
otner materials. Although the best source available to most
wells, productivity is low, seldom exceeding an adequate
house supply; occasionally it is inadequate. Many wells
are constructed with only surface casing, leaving almost the
entire hole open. Well deepening is a common practice.
Despite large areas with ro groundwater data, it is
apparent that the regional piezometnc slope is generally
northward. However, local variations exist. In this regard,
a large piezometnc ridge is suggested from Bend northeastward
through tne western portion of the project site areo. The
western limb of the ridge underlies a reach of the North Unic
Mair. Canal. Also, directly north of Bend the piezometnc
slope is locally eastward, forming a trough between this area
and the aforementioned ridge. The ridge might be maintained
by canal leakage, irrigation seepage, upstream river percolation,
and/or city sewage disposal. The indicated movement north o:
Bend may be caused frcn river or irrigation seepage, or both.
The deeper artesi-rr: aquifer tapped by the Forest Service
(and probably the Bend wells), is indicated to be an extensive
groundwater system conveying very large amounts of water fro.a
southerly source areas northward. The water level in the
Forest Service well stands at an elevation below water ie\'els
in regular deep wells, thus there is no upward movemoni;into
the mamsource aquifer zone. Similarly , there is probably
no significant movement of water down.vard into this underlying
artesian aquifer system in the general Bona project sitr area.
t Recharge and Discharge. With thci exception of thej deep
artesian zcr.o, local groundwater bodits are maintained jfrom
waters which percolate Iron the surface in this region.' Local
annual precipitaticn ave-ages 12 inches, probably insufficient
to generate significant recharge to groundwater. Therefore,
onl\ in v.cttor years is percolation fro-, precipitation probably
of recharge importance. Streams lo^e portions of their flows
to ground seepage m certain reaches. This ;s probably
urirrportant with regard to minor drainage in normal years.
Daschutes P.iver percolation is uncertain below Bend, but must
contribute at least so^e to sha]lover zones. Excess irrigation
water alsc percolate? -in-mo^t cases to add to groundwater
supplies.
71
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East and northeast of Bend, seepage losses fren canals
are indicated to constitute a substantial source of groundwater.
It is estirated that about 11 percent cf total flow in the
North Unit Main Canal is lost to seepage tetween Bend and the
Crooked River Canyon (Kstes, pers. comm.). Consequently, this
cculd rean an 8,000 to 10,000 acre-feet per year loss ir. the
stretch within and upstream of the project site. Considering
the other canals in this area, total canal losses could amount
to several tens of thousands of acre-fuet per year on the
average going to recharge groundwater.
North Unit Mam Canal losses do not maintain a localized
percolation ridge discernible by available data. Data on
12 wells, located within 1/8 to 1/4 mile of the canal south-
west of the project site, show that all but one water level
was in the 500-foot range or deeper. The exception well had
a level of 200 feet; ho; ever, a well a short distance away
was dry. Fron this, it is concluded that canal seepage effects
on groundwater are reflected broadly in the deeper tapped zone.
The injection of sewage effluent m and around Bend is
large enough to be a significant recharge factor. The city
sewage treatrent pier.*: discharges .5 million gallons per day
of treated effluent to a lava tube. City effluent has been
thus disposed of for many years. In addition, approximately
1/2 of the city's residents depend on septic tanks, which
discharge practically all household water to porous lavas.
Recharge to the deep artesian aquifer occurs to the south,
primarily fron river and snovnelt percolation.
In the general Bend area groundwater is discharged through
well pumpage and subsurface flow, basically in a northerly
direction. There is one recently constructed well on Site E.
The closest private wells to Site C are situated approximately
l'j miles '.\est and 2 rules norLinvest of the new troatm-'it
Thus, there is some groundwater discharge as well as subsurface
outflow in this vicinity. Whether or not the mam tapped
aquifer zone is capable of transmitting large amounts of
water laterally is somewhat questionable, considering the
poor well productivity. In any case, local additions to
this zoic must move through the area as jubsurfucc flo-.. unLiJ
ontcung the area of a well.
Groundwater Quality. Generally, groundwater is of excel-
lent mineral quality. Previous sr.'. pling by federal and statf.
agencies shew that total dissolved solids range from abc-ut 65
to 225 mg/lr hardness is commonly between about 2S ard 140 iy-'I ;
and maximum chlorides are on the oicer of 15 rr.g/1. There arc
reports of problem iron content but this is rot known to be a
widespread corcition, Cxcept for the possicle iron picolen
local Bend, area groundwater is very suitable for domestic
veil as irrigation purposes.
72
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Available groundwater quality data generally show r.o
important variations between wells or aquifer source. Partial
analyses of water from the Forest Service well indicate
it is similar to the average quality reported for other area
groundwaters, except that total dissolved solids (240-290 rr.g/1)
range nigher than most. Most variations are caused by the
occurrence of different rock materials which add additional
mineral matter to migrating waters. Overall mineral content
generally increases with distance downstream from the Bend
area due to greater contact tine with aquifer rock materials.
There are no data currently available on the quality of
groundwater underlying the project site. However, mineral
quality there should be similar to that to the west ar.d
southwest. Therefore, it is asrumed that site groundwater,
including perched water, if any, is of low mineral content
and acceptable for all normal uses.
Impacts of Subsurface Disposal - Drill Holes. The
potential for groundwater contamination is tne major problem
associated with effluent disposal to drill holes. Contami-
nation can occur through one of several mechanisms as follows:
1. Direct emplacement into potable water zones; F
2. Escape into potable aquifer by well-bore fail'ure;
3. Upward migration from receiving zone along the
outside of the casing;
4. Leakage through inadequate cor.Tining beds; •
5. Leakage through confining beds due to unplanned
hydraulic fracturing; '
6. Leakage through abandoned wells; f
7. Migration to potable water zone of the same aquifer.
Of these mechanisms, the first six have documented
instances o^ occurrence, while the seventh mechanism!is con-
sidered to be a probable occurrence the future. Tfhcrc
'are certain other mechanisms that a?re specifically related
to drill holes in the lava and sedimentary rock associated
with the cracks and crevices m these formations. Wastes
that find their way into these formations by whatever
mechanism are dispersed to unknown degrees and eventually
find their way to the groundwaters. An idealized pUre of
effluent travel m the regional aquifer from Site C is pre-
sented ir. Figure 6-1. If discharge is to a perched rcre,
the plume could travel ir an entirely different director..
There arc-basically two applicable mechanisms of attenua-
tion which would reduce the cort."1" mnnt concentration with ti~e
and distance traveled. The mecr.anisms are adsorption and -ctr.er
chemical reactions, and dispersion and dilution. Tae urknown
conditions here make it difficult to predict the degree of
contaminant attenuation. The mechanisms are briefly described
below.
7 3
-------
FIGURE 6-1
IDEALIZED PLUME OF
EFFLUENT FROM
SITE E
-------
Adsorption is the phenomenon whereby the surfaces of
solids m contact with water are covered with a thin layer
of molecules or ions taken up from the v ater and held tightly
by physical or chemical forces. The more finely divided the
soils, the greater is the surface area p^r unit volume and
therefore the greater the capacity for a"sorption.
Dispersion is the flow pattern of the contaminants
through the ground profile. In general, the contaminated
water moves to its destination by a definitive route and is
not subject to dilution from the entire body of groundwater.
An idealized system is shewn in Figure 6-2. However,
because groundwater systems seldom can be represented by the
"ideal" situation, dilution of the contaminated water body
probably takes place. Mechanical interactions between the
natural groundwaters and contaminated waters result m water
intermingling and therefore some dilution. Dispersion is
affected by the inherent capacity of the aquifer to cause
dispersion and also the velocity of groundwater movement.
As mentioned previously, the City of Bend has for many
years discharged sewage affluent to the ground. Such effluent
has received secondary treatment in recent years; formerly,
little or no treatment was given. Added to this, a large
portion of the city's residences (half or more) dispose of
liquid wastes through septic tank systems which discharge to
shallow drill holes averaging 50 feet m depth. No ground-
water effects of these public and private injections have
been detected thus far, although no detailed special studies
have been conducted.
This effluent first enters the fractured lavas overlying
the Deschutes formation, some perhaps going into lava tubes
or tunnels. By and large, it appears that it is successfully
dispersed m the subsurface. However, it is not at all certain
that as the quantities of local effluent increase, subsurface
limits for purifying it are not being closely approached,
particularly in the case of septic tank discharges. The close
proximity of septic tank discharges to uncased \vater wells
in the Bend area also may eventually lead to contamination of
local water supplies as depicted in Figure 6-3.
Fringri Impacts. Daily pollutant loadings for drill
hole disposal are estirated to be 350 pounds BOD, 150 pounds
suspended solids, 500 pounds nitrate and 250 pounds phosphorus.
The primary consideration in defining impacts of this projected
daily pollutant load on groundwater resources is that specific
hydrogeological conditions beneath the project site are un-
available at this time. Thus, they must be inferred from con-
ditions in neighboring areas. In view of variations from place
75
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FIGURE 6-2
FLOW IN A WATER-TABLE AQUIFER
GROUND-WATER
DIVIDE
DISPOSAL AREA
LEGEND
NOTE DRAWING NOT TO SCALE
CONSIDERABLE VERTICAL
EXAGGERATION
now lines
EQUIPOTENTlAL LINES
r~7'T1 contaminated ground water
IMPERMEABLE'ROCK
SOUNCE THE REPORT TO CONGRESS, WASTE DISPOSAL PRACTICES
AND THEIR EFFECTS ON GROUNDWATER, JANUARY 1977
-------
FIGURE 6-3
POTENTIAL MECHANISM FOR
CONTAMINATION OF UNCASED WELL
SHORT LENGTH OF
j SOURCE THE REPORT TO CONGRESS, WASTE DISPOSAL
PRACTICES 6. TMEIR EFFECTS ON GROUNDWATER,
JANUARr 1977.
77
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to place elsewhere, it is impossible to predict tho occurrence,
or nonoccurrence, of perched groundwater bodies and the nature
and even existence of the deep regional aquifer aoae tapped by
many area wells. Furthermore, these conditions could well
change markedly over the site area itself.
In addition, the apparently successful subsurface
disposal of effluent at Bend is considerably removed from
the site and may involve somewhat different subsurface con-
ditions. Until conditions are shown to be truly comparable
in either instance, the Bend experience cannot be directly
related to project prospects.
Positive Considerations for Subsurface Disposal.
1. The indicated percolation processes could apply,
in which any perched groundwater bodies receiving
effluent would eventually spill, or otherwise drain,
and there could be sufficient filtering sediments
above the regional water table to assist purification.
2. Dilution within the deep regional aquifer could
diminish any remaining vestiges of adverse effluent
quality.
3. It is likely that no significant amount of effluent
discharged to the subsurface would enter the deep
artesian aquifer system, potentially the most pro-
ductive and important groundwater resource in the
entire region.
4. Significant development and utilization of new
domestic supply wells on BLM lands to the north
could be controlled. Under BLM's Management Frame-
work Plan, public land to the north is designated
for multiple use management (i.e., grazing, watershed
protection, wildlife habitat management, etc.).
No disposal of public lands for private housing
development is planned (Paterno, pers. comm.).
5. An adequate monitoring program should detect any
developing problem in time to allow remedies before
major damage is done to groundwater resources.
Negative Considerations Against Subsurface Disposal.
1. Permeabilities of unlerlying lavas and sediments may
be too high to provide the filtration-purification
processes required. The closest drilling records
indicate that most, if not all, harder rocks encountered
are fractured or vesicular and the other materials
tend to be granular. Previous investigations cite
research in the Snake River Plain of Idaho involving
percolation of wastewater through basalt, clay and
rubble and suggest that some contamination of regional
groundwater would probably be unavoidable (U. S. EPA,
1977).
78.
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2. Perched groundwater zones may exist beneath the site
•hich do not spill laterally and/or leak-drain, as
assumed for most Bend area conditions. Effluent
discharged to the subsurface could thus build up to
high levels which would reduce discharge rates.
Although a remote possibility, considering the dis-
tance involved, uncased wells could act as conduits
downward for such fluids (see Figure 6-3).
3. Should the disposal well(s) be cased through perched
zones, it could involve losing much potential filtra-
tion benefits. Moreover, effluent discharged directly
in or even near an aquifer is fundamentally undesirable
in any case.
4. Subsurface disposal of effluent at the current treat-
ment plant may net be a valid example for comparison
of project site potential. Harmful effects could be
accruing which will become troublesome in the future.
It is possible that contamination exists at present,
but gees unnoticed.
5. There is no guarantee of the local ability of the
deep aquifer zone to rerove this additional inflow
efficiently, or that it even exists in the usual form
at this location. Some well experience has found the
aquifer to be tight and several dry holes are reported.
Prior to obtaining final results of recently completed
exploration and testing of subsurface conditions on Site E,
it is not possible to reasonably project what the effects
would be on groundwater uses from discharge of project effluent
into the ground. Whereas much will be learned from test
drilling, particularly regarding optimum disposal well 'design,
actual subsurface discharge tests would bo needed, involving
a simulated project operation, plus monitoring of groundwater
in adjacent piezometers, to establish probable capabilities
of this area to disperse fluids at the rate required. ,Puri-
fication of effluent could not be tested m advance.
» Should drill-hole disposal of eftluent be pursued, it should
be set up on an expern. ental basis, with the prospect Jthat it
will be interim only. Accordingly. other disposal procedures
must be available for use in the event subsurface discharge
provides unsatisfactory.
Sr co>• i' i Impact*. Should water resources become contami-
nated by an ongoing disposal operation to the extent that
existing domestic water users frcr wells or springs are pre-
vented from utilizing their supply, suc'i supply will remain
polluted to that level, or worsen, as long as the offending
disposal continues",- ancT'lcnger. L'r.dtr such conditions, would-
be domestic water users would also be d'^r.crred from using the
same supply.
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The deep regional aquifer commonly utilized in the region,
and which is assumed subject to contamination, is characteristically
inadequate for more than minimal irrigation supplies. Consequently,
irrigation use does not appear to be a realistic alternative
well use for affected households.
If the stated aquifer becomes unusable, replacement wells
and any new wells would have to be drilled to the deep artesian
zone.
Impacts of Subsurface Disposal - Infiltration. Daily
pollutant loadings to infiltiation ponds are estimated to be
1,500 pounds BOD, 1,500 pounds suspended solids, 1,000 pounds
ammonia and 400 pounds phosphorus. Removal efficiencies for
infiltration ponds should be greater than those for drill
hole disposal because effluent would travel through approxi-
mately 3 feet of soil before entering the groundwater. Removal
of BOD, suspended solids, viruses and bacteria has in recent
studies been calculated to be greater than 98 percent in
infiltration ponds. Other contaminants such as nitrates and
phosphorus have shown removal efficiencies as high as 80-96
percent (Pound and Crites, 1973). Actual pollutant removal
efficiencies for soils in the Bend area, however, are not
known. Monitoring programs would provide needed information.
Impacts of Deschutes River Disposal. Deschutes River
percolation to groundwater is uncertain below Bend, but is
thought to contribute some water to shallower zones. The
dilution of effluent discharged to the river in winter would
be very great. Thus, the effects of winter discharge on
groundwater would be insignificant. Summer discharge of
effluent to the canal, however, would receive less dilution
and could have some effect on shallow perched groundwater
zones. The contamination risk, would be less tnan that for
subsurface disposal to drill holes because of the dilution
effect of river water, some biological decontamination in the
river environment and reduced effluent quantities received by
groundwater zones.
Impacts of Evapotranspiration Ponds. Evapotranspiration
ponds would be sealed with clay material and by natural
processes, and canals would b^ sealed with cement to prevent
seepage of effluent to the groundwater. Thus, there should
be no impact on groundwater from these ponds. Impacts on
groundwater from infiltration basins included in this alterna-
tive would be similar to those discussed under subsurface
disposal-infiltration ponds. The potential for groundwater
contamination in this case would be reduced because less than
half of the effluent produced would be discharged to
infiltration ponds.
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Impacts of Land Application by Spray Irrigation.
Although soils are thin in places over lava bedrock, they
would supply an important element of effluent treatment at
the outset of deep percolation. The proper crop will also
remove much of the nutrient load. Percolation from the
ground surface would give a longer filtration path than for
subsurface disposal.
A large portion of the water applied would be consump-
tively used by the crop and evaporated from the adjacent soil.
Consequently, only a minor portion of total waste discharge
would be available to percolate below the root zone to ground-
water. This amount has not been officially estimated yet,
but, under proper management, probably on the order of 20
percent or less of applied effluent would so percolate in
summer. Of course, the winter-time rate of crop consumptive
use would be lower, but so would effluent discharge. However,
for the year, it is reasonable to assume that less than half,
and perhaps only 30 to 40 percent of plant effluent, would be
excessive to crop evaporation demands and thus tend to perco-
late downward. Percolate would be diluted somewhat in winter
by precipitation.
Dispersion of the discharge over the large specified
area, and perhaps additional land, rather than concentrating
it at only one or several point sinks, makes a vast difference
in the subsurface ability to absorb, filter, and eventually
transmit the added water from the area.
All factors considered, it is concluded that area ground-
water resources woulc not be adversely affected by sprav-
irrigation disposal of plant effluer.t under a properly managed
operation.
Impacts of North Unit Majn Canal Disposal. As previously
stated, available well data near the canal show only a deep
water level in the 500-foot range. Seepage from the canal nay
be temporarily retained m one or more perched zones, but there
is no evidence that any significant shallow water table is thus
maintained. Consequently, canal seepage is assumed to percolate
deeply to the regional groundwater zone utilized by most wells
in the fashion previously described.
The dilution cf effluent discharged to the canal in
summer would be very great. Translated into quantities of
effluent which might seep from the canal, the total is very
small. Thus, the effects of summer effluent discharge into
the canal or gro -.ndwater should be insignificant.
81
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On the other hand, discharge to the canal in winter when
it is empty would not bo expected to proceed a great distance
down the canal before entering the ground. BECOH has esti-
mated this distance to be approximately B miles (Design
Definition Memorandum #10). This would involve some of the
same elements as subsurface discharge with some of the same
contamination risk. Therefore, subsurface conditions would
have to be explored by test drilling and the operation
monitored using somewhat similar though less stri-.gent
procedures. There would be some winter dilution of effluent
from precipitation, which would mitigate effects to some extent.
Impacts of the No-Action Alternative. Adoption of the
no-action alternative (discharge of secondarily-treated,
chlorinated effluent from the present wastewater treatment
plant to a lava tube and discharge of inadequately treated
wastes to the subsurface from individual disposal wells)
could eventually have an adverse effect on groundwater supplies
in the Bend area. The potential for groundwater contamination
would be greatest under this alternative because effluent
entering the subsurface would receive minimal treatment. in
addition, projected population growth in the City of Bend would
magnify the potential for groundwater contamination. Because
the present treatment plant has a capacity of 2 mgd, it would
not be possible to connect residents now on septic tanks or
new residents in the Bend area to the sewer system without
expanding the treatment plant. This would result in thefcon-
tinuation of subsurface disposal of inadequately treated)
wastewater which, after 1980, would be in violation of
OAR 340-44-045. This regulation prohibits the use of waste
disposal wells after January 1 of that year unless approved
and authorized by the DEQ.
Surface Waters - Deschutes River
The Deschutes River flows to the north through the]
study area. Beneficial uses of the river include recreation,
fiph rearing and spawning, irrigation end domestic uses'.
Four state parks are located on the river between the B'end
diversion dam and Round Butte Dam. Lake Chinook is a popular
recreation area for swinwing, water skiing and fishing.
Fishing use of this portion of the river in 1970 was estimated
to be 6,300 angler days (Fies, pers. comm.).
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Fifteen private domestic water diversions are located
on the Deschutes River between the Bend diversion dan and
Lake Chinook- All are located between the diversion dart and
the town of Tumalo (Figure 6-4). In addition, 20 miles
downstream from the diversion dam the City of Redmor.d utilizes
river water in winter as an emergency backup source for two
city wells. Deschutes River water has not been used for
this purpose, however, for the last three years (Edwards,
pers. comm.). The city's major water source in summer is the
Pilot Butte Canal, which diverts Deschutes River water above
the Bend diversion dam. City residents receive water that
has gone through a process of coagulation, sedimentation and
chlorination.
The City of Redmond also has developed plans to utilise
Deschutes "ivcr water as a future year-round domestic supply
because ot current problems with canal water quality and well
operation (Edwards, pers. comm.).
Impacts on Surface Water. For effluent discharge to the
Derchutes River, the projected pollutant loadings from the
treatment plant are as follous: BOD at 350 poundr, per day;
suspended solids at 150 pounds per day; ammonia-nitrogen at
1,000 pounds per day and phosphorus at 250 pounds per day.
Based on the low flows anticipated during the winter months,
a dilution ratio of approximately 14 to 1, based on estimated
low flow conditions of 150 cfs, would result in a minimum of
contaminant concentration increases. The quality of effluent
discharged to the Deschutes River would meet all existing
standards. There would be a small oxygen deficit which would
not cause the dissolved oxygen concentrations to fall below
90 percent of saturation, which is the required minimum value.
These conditions, however, would be magnified substantially
for discharge to the Deschutes River during the summer months,
when the low flow conditions have been determined to be 15.5
cfs. The oxygen saturation would fall to approximately 8 5
percent of saturation, which is nominally below the 90 percent
value required by state standards.
There should be no impact on Deschutes or Crooked Rivers
water from subsurface disposal or land application of effluent.
Deep groundwater recharge to streams is many miles northward
in the Crooked Uiver Canyon, primarily in the vicinity of Opal
Springs. It is projected that no project contaminants would
be measured at these recharge areas.
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TuUALO STAT£ PARK
FIGURE 6-4
LOCATIONS OF DOMESTI
WATER DIVERSIONS AND
RECREATIONAL USE ON
THE DESCHUTES RIVER
BELOW BEND
- L-E: ge: no -
• DOMESTIC WATER DlVESSiC*
V//P STATE PARK WITH WATER
C/3 CONTACT ACTIVITIES
TUMAlO
#oei*t saw ¦ •[#
STATE PARK
BEND
C
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Surface Waters - Korth Unit Main Canal System
The North Unit Main Canal, which is a Bureau of Reclamation
project operated by the North Unit Irrigation District, is
approximately 65 miles long with 235 miles of laterals. The
canal system diverts watE.r from the Deschutes River at DcncI for
agricultural and limited domestic use in Jefferson County. Crops
grown using canal water include fresh vegetables, potatoes,
garlic and peppermint. The Cities of Madras, Metolius and
Culver utilize canal water for various purposes. In years of
low precipitation water is al^o diverted from the Crooked River
where the canal crosses the river canyon. Figure 6-5 shows
the route of the North Unit Main Canal and the 58,000 acres of
agricultural land served by the irrigation district.
Haystack Reservoir, at canal mile 40, acts as a regulating
reservoir for the ctnal system to reduce operational waste.
During the irrigation season water levels in the reservoir
can fluctuate in excess of 1 foot per day. Morphonetric
data for Haystack Reservoir is given in Table 6-2. The
reservoir is a recreational area for swimming, water
skiing and fishing. An estimated 29,214 recreationists
visited the reservoir in 1977 for water contact activities
(Crooked River National Grassland, unpublished data).
A private rescrt is located on the south side of the reservoir.
Flows in the North Unit Main Canal average approximately
700 cfs for 6 1/2 months of the year (mid April through October).
The canal carries no flow for the remaining 5 1/2 months.
During the irrigation season, sign:ficant waver losses from
the canal occur through seepage. As previously stated,
these losses approximate 11 percent of canal flow between
Bend and the Crooked River Canyon (Estes, pers. corrjn. ^.
Excess canal water eventually returns to the Deschutes River
via spillways at Willow, Mud Spring and Trout Creeks.
i
The sole user of canal water for domestic purposes is
the City of Madras, which diverts approximately .5 cfs from
the canal at mile- 56 durmu the irrigation season to sucpler: ent
— - pr-" y » r
three city wells. Canal water receives coagulation, sedi-
mentation and chlorination treatment prior co use by city
residents. The Cities Of Metolius and Culver use canal water
for vegetable production, lawns and yards.
Impacts on Surface Water. Daily pollutant loadings to
the irrigation canal for BOD, suspended solids, ammonia, and
phosphorus would be 3 50 pounds per day, 150 pounds per day,
1,000 pounds per day, and 250 pounds per day, respectively.
These numbers are_ based on typical values from an activated
sludge plant achieving a "iO/10" (10 mg/1 BOD and suopcrJc-d
35
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mo*rm vmtr
t»*/matto* otsr»/cr
styrusrus
LAKE
CHINOOK
HAYSTACK
RESERVOIR
DCSCHUT£ S CO.
REDMONO
FIGURE 6-5
THE NORTH UNIT IRRIGATION
DISTRICT CANAL & RESERVOIR
SYSTEM
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Table 6-2
MORPHOMETRIC DATA
Morphometry
Surface area
Volume (2,842 feet
pool elevation)
Mean depth
Maximum depth
M = million
m = meters
HAYSTACK RESERVOIR
225 acres (105 Mm2)
5,650 acre-feet (8,690 Mm3)
25 feet (7.65 meters)
68.5 feet (20.9 meters)
Source: U. S. Bureau of Reclamation, 1972.
87
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solids) effluent quality. Based on the typical average flow
in the North Unit Main Canal of 700 cfs, a dilution ratio of
77 to 1 would result at a 6 mgd flow rate. At low flows in
the canal reported to be approximately 59 cfs within the last
five years, the dilution ratio would be 6.5 to 1. The colifori.;
count would be kept below 10 MPN/100 ml.
Eutvonkicatior. Voter.tial. The lack of water quality data
(from Storet, 1978) in the Deschutes River basin allows only a
cursory analysis and a crude estimate of potential eutrophi-
cation problems in the North Unit Main Canal system. Deschutes
River water at the Bend Diversion Dam is relatively soft with
little buffer capacity (alkalinity - 30 mg/1 as CaC03, total
hardness - 20 mg/1 as CaC03). The pH (7-8.3) and DO (86-109
percent saturation) values indicate little primary productivity
problems. A marked productivity increase occurs west of Cove
State Park (pH - 7.5-9.3,- DO - 97-165 percent saturation) fror.i
input of Crooked River water, which is of poorer quality.
The North Unit Main Canal requires treatment with xylere
to remove objectionable plant growths indicating an input of
nutrients from the Deschutes and Crooked Rivers and from
within the canal system. These plants interfere with flow as
well as affecting aesthetics and water quality.
A detailed water quality analysis of the existing canal
system is available in appendix form upon request. |
Based on phosphorus as the controlling variable, results
of the W£-ter quality analysis indicate that Haystack Reservoir
would become eutrophic (nutrient-rich) if all effluent entered
the reservoir. Bypassing up to 50 percent of the effluent
would still produce eutrophic conditions. Bypassing 7 5 percent
of the effluent would result in mesotrophic (moderately
nutrient-rich) waters. Historically, water quality in the
reservoir has been poor and addition of project effluent could
accelerate reservoir eutrophication as well as adversely effect
water quality in the North Unit Main Canal. I
.• ' I
To confirm these predictions, however, monthly analyses
for a year of samples collected at a number of points along
the canal and in the reservoir for total P, orthophosphate P,
NH3-N, NO3-N, NO2-N, TKN, pH, DO, temperature and alkalinity
would he a minimum program. Secchi depth and chlorophyll a
analy&cs in Ilaystack Rer ervoir would also be appropriate.
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If modifications to year-round canal disposal were imple-
mented such as irrigation season canal disposal in combination
with winter disposal to the subsurface or the Deschutes River,
annual pollutant loading to the canal would be reduced by 42 to
50 percent, or by that amount no longer discharged to the
canal in winter. If the effluent were to reach Haystack
Reservoir, the potential for accelerating eutrophication
would also be reduced.
In the case of canal disposal in combination with winter
storage, pollutant loadings are difficult to estimate, because
the degree of treatment while in storage is unknown, and can
only be estimated. Assuming effluent from the storage
reservoirs would be recycled through the filtering system
prior to discharge in the canal, effluent quality from storage
would be approximately equal to that being discharged directly
fro:n the treatment plant. Annual pollutant loadings would,
therefore, be approximately the same as for year-round canal
discharge, but would be accrued over the 6-1/2 month irrigation
season rather than over the entire year. This means that
daily pollutant loadings on the canal during the irrigation
season would be somewhat greater than that stated for year-
round canal disposal. However, the magnitude of this potential
increase in pollutant loading can not be accurately estimated.
In any event, a small elevation in daily pollutant loading
would probably not change the potential for adverse impacts on
water quality in the canal system beyond those stated for year-
round disposal.
There is also a potential for adverse impact on the
Deschutes River from effluent disposal to the North Unit Main
Canal. Irrigation return flows to the Deschutes River from
the canal system could contain additional nutrients and
herbicides thereby further degrading existiry iiver water
quality.
Public Health
Impacts of Subsurface Disposal. Potential health hazards
are associated with contamination of groundwater by bacteria
and viruses and chemical compounds such as ammonia and nitrate,
carcinogens, organics and toxic substances. Nitrate concen-
trations in groundwater over 10 mg/1 measured as nitrogen have
been documented as causing methemoglobinanemia "blue baby".
Other compounds such as total dissolved solids can be harmful
89
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to people with cardiac, respiratory or viral diseases, if high
levels are present in drinkiny water supplies. The fate of
the other contar.iinants listed above cannot be determined v;ith
any degree of reliability. Suffice it to say that the mechanisns
of filtration, adsorption and dilution would lessen the impact
of these contaminants.
The potential contairinants of greatest concern are patho-
genic bacteria ana viruses. Dilution and disinfection, in most
cases, renders potentially hazardous substances safer by
lowering the risk of contamination. Particular features of
these processes are described below. A more detailed accounting
of the risk of effluent disposal to human health is available
in appendix forn upon request.
Dilution. Over one million acre-feet per year surfaces
in springs in the Crooked River Canyon area north of Redmond.
This is commonly used as a minimal estimate for groundwater
flow. Complete mixing of discharge wastewater into this
volume of groundwater would give a dilution ratio of 1 part
effluent to 150 parts of groundwater. The dilution effect,
however, would most probably be less than this since as stated
by Sceva (1968) "once the waste water or effluent from a septic
tank reaches a perched or regional water table, it flows down
the hydraulic gradient. As most groundwater flow is under
laminar conditions, there is much less dispersion of the
effluent in groundwater than in surface water".
Disinfection. Saturated flow of groundwater through soil
can be effective in the removal of bacteria as is shown in
Table 6-3. To make a conservative estimate of the number of
microorganisms transmitted through a relatively coarse medium,
sedimentation should be considered the primary mode of action.
In this instance the p in Table 6-3 represents filterability
by sedimentation. This ignores the other physical-chemical
phenomena as well as natural die-off.
Assuming the coarsest sand size (0.11 cm) one would
estimate that within 50 feet a 99.5 percent reduction in
bacteria would occur; and within 100 feet the reduction
would be in the range of 99.998 percent.
Recently, Dr. Robert Cooper, University of California,
Berkeley, conducted a test in which a groundwater aquifer
was recharged with secondary effluent to which polio virus,
ECHO virus and coliphage was added. The sampling well was
25 feet from the injection well. The removal rate at this
distance was 99.9999 percent. Thus, flow through the saturated
zone appears able to remove considerable amounts of animal
and bacterial viruses.
90
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Table 6-3
REMOVAL OF COLIFORMS BY SEDIMENTATION IN SATURATED SAND
OF VARIOUS EFFECTIVE SIZES
Effective Removal of Coliforms Per Travel Distance (c/cn)**
Sand Size
i
cm v Value 0.5 ft. 5.0 f t. 10 ft.
0.11 0.0035 0.949 0.592 0.350
0.04 0.0169 0.776 0.008 „ 0.006 16
0.019 0.1200 0.165 1.52 x 10- 2.3 x 10-
lA QQ 99
0.0063 2.000 9.3 x 10- <1.0 x 10- <1.0 x 10-
*Flow rate 0.044 to 0.52 cm/sec
**Final concentration of coliforms/initial concentration
15 ft.
0.207
0.0005 24
3.5 x 10-
99
<1.0 x 10-
Adaptcd from: Krone, "et alv>--1958.
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The aquifer will also present ion exchange capacity,
biological activity and sorption capacity for inorganic and
trace organic compounds. This will reduce even further the
concentration of chemicals in the water of wells down gradient
from the injection site. Eventually equilibrium will be reached
and a rather constant concentration of the chemicals will be
found in the pumped water.
The conclusion to be drawn is that the passage of water
through a saturated zone can effectively remove biological
agents and reduce the concentration of chen.i^al agents.
Subsurface disposal via infiltration ponds would be expected
to provide a greater degree of removal efficiency than would
drill hole disposal because effluent would pass through a
layer of soil before entering the underlying strata. An
adequate monitoring program would be necessary to determine
the contaminant removal efficiency of the underlying rock
formations as well as that of the infiltration ponds.
An additional health risk associated with infiltration
ponds would be the potential for mosquito propagation.
Bacterial or viral diseases could be transmitted to man or
animals by this means.
It is expected that infiltration ponds, because of their
strict operational design, would be fenced to prevent public
acce&L. Therefore, health risks relating to direct contact
with effluent would be restricted to operators. Skin contact,
as it might be associated with ingestion or food contact,
would be of concern; however, good personal hygiene on the
part of operators would presumably minimize potential problems.
Public health risks of a different nature would also be
associated with the location of infiltration ponds in relation
to the Bend Airport. According to FAA regulations {Chapter 5)
any infiltration pond located on Site E in the vicinity of
the new treatment plant would fall into the FAA prescribed
safety zone and would thus pose a significant threat of bird
strikes to aircraft approaching the airport. Any infiltration
ponds within this safety zone would require wire screen or net
covering to repel birds (D. Field, FAA, letter to EPA dated
August 14, 1979). Infiltration ponds constructed in the
natural depression to the east of Site E (see Figure 4-1) would
not lie within the FAA safety zone.
Impacts of Deschutes River Disposal. Discharge of dis-
infected and filtered secondary effluent into the Deschutes
River would result in dilution of the biological and chemical
agents present in the effluent. To be conservative the lowest
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dilution during the wet and dry seasons were chosen. From
these dilution ratios of 14 to 1 during the wet season and
less than 2 to 1 during the dry season, it was determined
that from November to March the treatment plant's contribution
of conforms would be about 1 per 100 ml, and about 2 viruses
per liter. It should be noted that from 1970-1974 the
coliform level observed in the water of the Deschutes River
above Bend averages 680 per 100 ml (ranges from 23-7,000/100
ml) and the fecal coliform level averages 646 per 100 ml
(ranges from 5-7,000/100 ml). The estimated contribution of
the treatment plant would be extremely small compared to the
reported background levels. During the dry season (April-
October) the dilution would be correspondingly less, yet the
contribution of coliforms would still be only a small percentage
(approximately 1.5 percent) of the average background numbers
of these bacteria.
Chemical compounds present in the discharge would be
diluted in a manner similar to the biological agents. One
would expect most heavy metal concentrations to be reduced
to levels acceptable for drinking water. Nitrate would be
significantly reduced in the wet season and much less so
during the dry season. Nitrates are reported (1970-1974) to
average 0.07 mg/1 as NO3-N in the Deschutes River above Bend.
Thus, effluent from the treatment plant would give a large
proportionate increase in nitrates but should be below
acceptable drinking water maximum. During the dry season
the dilution would be significantly less and the nitrate
level would be greater accordingly.
As the biological and chemical agents move downstream
there would also be some reduction due to natural decay,
adsorption and other physical-chemical processes. The extent
of the activity of these processes in the Deschutes River is
unknown, particularly for chemical entities. The half life
for viruses and bacteria in natural waters has been estimated
to be in the range of 4 to 30 hours. Thus, unless a stream
is particularly sluggish the impact of natural decay on
relatively close, downstream stations should be negligible.
In estimating the health risk to downstream water users the
most conservative approach is to assume that these various
removal processes would have a minimal effect upon chemical
and biological agent concentrations.
The City of Redmond may in the future take drinking water
from the Deschutes River during the dry season, the period
of least dilution of the upstream Bend treatment plant effluent.
Conventional water treatment processes (coagulation, sedimen-
tation, filtration and disinfection) should effectively reduce
93
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biological agents present to an acceptable public health
level. The removal of organic compounds by conventional
water treatment is not anticipated, however, to be of any
significant magnitude. Thus, if the increased organic load
were to affect Redmond drinking water quality then activated
carbon treatment would need to be added to the process.
High nitrate levels could also cause problems to the Redmond
water supply.
Individual water supplies taken from the river would
normally not have the benefit of complete treatment. It is
assumed that the microbial quality of the Deschutes River
is presently questionable due to causes unrelated to Bend's
municipal waste disposal. Thus, the anticipated contribution
of bacteria and viruses from the proposed Bend discharge
would not significantly increase the probability of infectious
disease to those individual households who now use the river
water. The chemical impacts could be more significant upon
these individuals. As a safeguard, downstream domestic use
of river water by private residences would probably be pro-
hibited.
The public health threat to the recreationist using the
river should be insignificant, although it should be noted
that the low flow times of year would be the time of most
swimming and recreational boating contact.
Impacts of Evapotranspiration Ponds. Daily pollutant
loading to sealed evapotranspiration ponds and infiltration
basins under this alternative would be 1,500 pounds BOD,
1,500 pounds suspended solids, 1,000 pounds ammonia and
400 pounds of phosphorus. Coliform bacteria levels would
be approximately 1,000/100 ml of effluent.
Infiltration basins would be fenced to prevent public
access. Evapotranspiration ponds developed as wetlands,
however, could be made accessible to the public. Thus, the
major public health risk would be from skin-to-mouth contact
or from drinking effluent directly. As effluent travels
through the series of evapotranspiration ponds, howevjer,
concentrations of the above pollutants should be reduced
substantially through natural decay, uptake by aquatic vege-
tation and settling. Studies by Woodwell (1977) utilizing
marsh environments to treat domestic sewage showed removal
rates for inorganic nitrogen and phosphorus of over 90 percent
within a period of seven days.
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Bacterial concentrations in the effluent would be reduced
over time by natural die-off. Survival time of pathogenic
bacteria in water has been reported a:; being from several
weeks to over three months (Pound and Crites, 1973). It
should be noted, however, that coliform levels in the Deschutes
River below Bend have been reported as high as 7,000/100 ml
with no apparent effect on downstream uses.
Viruses in the effluent would also be subject to natural
die-off over time with survival times in water reported less
than one month for some organisms (Pound and Crites, 1973).
Mosguitos could also be potential carriers of diseases
to man if propagation were to occur in evapotranspiration
ponds or infiltration basins.
An additional public healch threat is associated with
the location of evapotranspiration ponds in relation to the
Bend Airport as discussed previously under impacts of sub-
surface disposal-infiltration ponds on public health. Two
tentative locations for evapotranspiration ponds would lie
within the designated FAA safety zone and would, therefore#
be unsuitable locations for marsh areas. One ponded area
is located within Site E and a second, southernmost pond, is
adjacent to the Powell Butte Highway (see Figure 4-3).
Impacts of Land Application by Spray Irrigation. Under
this alternative, the public health concern would involve
exposure to field workers, aerosol generation and contami-
nation of the underlying groundwater. Crops to be irrigated
would include various grasses, some of which can be used for
animal fodder. No leaf or root crops for human consumption
would be involved.
When reclaimed water is used for sprinkler irrigation
the chances for ingestion of large volumes of water (100
to 1,000 ml) is rather small. The major route of contact
would be from hands contaminated with reclaimed water placed
in one's mouth, from ingestion/inhalation of aerosols generated
by such activity or from drinking water directly. This latter
situation may arise when workmen drink from irrigation hoses
or hose bibs or in a situation in which the reclaimed water is
accidently cross-connected with the potable water supply.
Skin contact should be of minimal concern except as it
might be associated with ingestion or food contact. Good
personal hygiene among those exposed should prevent any
problem. An important route of contact will be respiratory.
The ability of disease transmission via aerosols is an
extremely complex combination of factors which include the
95
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nature of the agent, size of aerosol particles, distance of
travel, relative humidity, sunlight, ambient temperature,
characteristics of the exposed host, etc. At present the
evaluation of the effect of aerosols upon the health of
those exposed must be based upon existing field measurements
and upon epidemiological experience in instances where
wastewater is aerosolized.
No data are available which indicate that the aerosols
generated by activated sludge plants have been the source of
disease either for plant personnel or for downwind communities.
Plant personnel are exposed to considerable aerosolized material
originating from a significantly more concentrated source of
agents than that proposed to be used in the Bend project.
One hundred to two hundred feet should be considered an adequate
sanitary buffer zone between activated sludge plants and houses.
The health effects of chemicals in reclaimed water used
for irrigation have not been investigated except as runoff
may affect surface supplies or chemicals, such as cadmium,
may be translocated into edible plants. The impact of
aerosolization of chemical agents has not been discussed
in the open literature. The amounts of these agents in the
applied water should generally be in the microgram level. The
tremendous dilution effect of the air would be expected to
reduce these concentration levels far below the background
created by auto emissions, .industrial effluvia and the like.
Although the land irrigation alternative does not offer
a dilution effect, the soil mantle is recognized as an effec-
tive treatment system for wastewater. An estimate of coliform
removal by soil systems can be made utilizing data from
Table 6-4. In the most coarse soil (Oakley Sand) from one to
three orders of magnitude reduction in coliform numbers would
be expected within the first 3 feet of the soil horizon. If
the application rates at the proposed Bend sites are less
than 0.18 to 0.21 feet per day, then removal rates might be
expected to be even greater. Thus, within a few feet of soil
depth a coliform level in percolated water of less than 1 per
100 ml would be expected.
Data on virus-soil interactions are not as well developed
as that for bacterial agents. Removal will be effected by
application rates and clay content of the soil. In one study
(Lance and Gerba, 1977) after application of viruses to rapid
infiltration soil columns at hydraulic rates of 6 to 22 inches
per day the detection of viruses was limited to soil depths
less than 69 inches with 90 percent or more removed within the
first few inches. It can therefore be concluded that the
96
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Table 6-4
SOIL TEXTURE AND COLIFORM COUNT AT A DEPTH OF 3 FEET FOR
FIVE SOILS UPON WHICH SEWAGE WAS SPREAD
Effective
Size (rrm)
Flow Rate
Feet per Day
Percent Coliform
Removal
Hesperia sandy loam
0.0020
0.23
99.985-99.99997
Columbia sandy loam
0.0033
0.18
99.990-99.99997
Hanford sandy loam
0.0074
0.21
99.904-99.9998
Vale sandy loam
0.021
0.23
99.900-99.9998
Oakley sand
0. 020
0.21
90.000-93.9782
Adapted from: Orlob and Butler, 1955.
-------
occurrence of enteric viruses beyond a few feet of soil, when
water of the projected quality to be produced at the Bend
plant is applied, would be of low probability.
Nitrate generation or removal will depend upon application
rate, soil type and crop. In some instances where long-term
applications have been practiced, such as at Lubbock, Texas
(Pound and Crites, 1973) increases in groundwater concentra-
tions of nitrate have been observed.
Control of insects on a wastewater irrigation site is
more critical than on a conventional irrigation site because
of the possibility of effluent contamination by bacteria or
viruses. Mosquitos could reproduce in storage reservoirs or
on irrigation sites where any ponding of effluent occurs and
thereby carry diseases transmittable to man.
Impacts of North Unit Main Canal Disposal. This alterna-
tive has similar aspects to effluent discharge to the Deschutes
River; however, when the canal is in use, the dilution factor-
would be at least five times greater at low flow than that of
the river.
The public health risk of greatest concern would be to
users of canal water for domestic purposes in Madras. The
city uses conventional water treatment processes to purify
canal water for domestic use, which should effectively reduce
any biological contaminants to acceptable public health levels.
Removal of organic compounds and nitrates, however, might not
be complete and could therefore adversely affect public health.
The City of Madras reportedly has existing problems purifying
poor quality canal water for domestic use (Miller, pers. comm.).
Additional nutrients from effluent could aggravate this problem.
The risk of contracting bacterial-caused diseases should
be minimal to users of canal water containing effluent for
irrigation of crops or yards or to persons consuming crops
irrigated with this water. Effluent would contribute an addi-
tional 10 MPN/100 ml to canal waters, an insignificant arrount
of pollutants when compared to bachground coliforn levels as
high as 7, 000 K.PN/100 ml potentially entering the canal at the
diversion dan. This level of bacterial contaminants would be
similar to coliform levels currently existing in several streams
elsewhere in the state v^here river water, receiving treated
sewage effluent, is used to irrigate crops grown for direct
human consumption. For example, the Willamette River receives
effluent fron numerous city treatment plants (e.g., Euger.e,
Corvallis, Salem, Albany, etc.). V.'atcr frcm this river is
used to irrigate a wide variety of truck crops including beans,
onions, strawberries and carrots. Total coliforn levels in
98
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this river have
-------
The concentration of unionized ammonia which has been determined
to provide safe levels for all species of aquatic life is 0.02
mg/1 (Thurston, et al., 1978). The concentration of ammonia in
the Deschutes River, which would result in toxic concentrations,
is affected by the temperature and pH of the water. Based on a
water temperature of 11.5°C and an average pH of 8, the allow-
able ammonia concentration is 1.0 mg/1. At the discharge point,
however, concentrations of ammonia in the mixing zone would be
approximately 1.2 mg/1. Special treatment facilities would
therefore be required to lower the effluent ammonia concentra-
tion to a safe value.
Another potential problem is that of chlorine toxicity
to aquatic life when chlorine concentrations are higher than
the safe value of 0.003 mg/1 (Thurston, et al., 1978). Based
on low flow conditions in the river, this value would be
exceeded and dechlorination of the effluent would have to be
included to maintain the beneficial use of the fishery.
Effluent disposal to the North Unit Main Canal is also
projected to increase ammonia concentrations in the canal
system. However, at an average flow of approximately 700 cfs
in the canal during the irrigation season, ammonia concentra-
tions would be approximately 0.32 mg/1 which is substantially
below the allowable level of 1.0 mg/1. Therefore, ammonia
should not adversely affect fish in the canal or reservoir.
Chlorine concentrations in the canal system would be
approximately 0.006 mg/1 at the discharge point. At a fish
toxicity level of 0.005 mg/1, addition of chlorine to the
canal could adversely impact the fisheries.
Accelerated eutrophication of Haystack Reservoir could
also have an adverse impact on the reservoir fishery. Increased
algae and aquatic plant growth could cause dissolved oxygen
concentration to fall below tolerance levels of resident species,
particularly cold water species, such as trout and kokanee.
Extensive fish kills, thought to be the result of low dissolved
oxygen concentrations in the reservoir, have occurred in the
past under current reservoir water quality conditions.
Additional nutrients added to the system by effluent discharge
could aggravate this existing problem.
100
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Wildlife
All alternatives of effluent disposal, except no action,
would have some degree of impact on wildlife. Placement of
disposal facilities (e.g., ponds, cropland, storage reservoirs)
would result in long-term losses of wildlife habitat utilized
by native species.
Habitat losses would be of greatest significance under the
land application by spray irrigation alternative, which would
require conversion of at least 1,350 acres of juniper-sage
brush habitat to cropland. The infiltration and evapotrans-
piration alternatives would also impact substantial acreage.
Habitat losses under these alternatives, however, when com-
pared to available juniper-sage brush habitat in central
Oregon, would be relatively insignificant.
In construction areas, subsurface dwelling and sedentary
mammals and reptiles would be destroyed. More mobile species
displaced from construction sites could also be lost, if
surrounding habitat already supports a carrying capacity of
that species.
Operation of the spray irrigation system, infiltration
ponds and evapotranspiration ponds would produce some secondary
benefits by providing new habitat for species adapted to agri-
cultural practices and aquatic habitats (e.g., waterfowl,
blackbirds, etc.). Establishment of "islands" of greenery
could increase the density of some native species inhabiting
adjacent undisturbed habitat through creation of an "edge"
effect.
Vegetation and Soils
All effluent disposal alternatives, except no action,
would have some degree of impact on existing vegetation.
Placement of disposal facilities (e.g., croplands, storage
reservoirs and ponds) would result in long-term native vege-
tation losses. The land application by spray irrigation,
infiltration and evapotranspiration pond alternatives would
have the greatest impact.
Both beneficial and adverse impacts on soils and vege-
tation may result from spray irrigation of effluent. Eenefxcial
impacts include increased soil fertility, increased soil organic
matter content, and more vigorous plant growth from nutrients
such as nitrogen, phosphorus, potassium, lime trace elements
and humus, supplied by the effluent. Potential adverse vmpacts
of effluent disposal on soils and vegetation arc overloading of
101
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organic matter, which could clog the soil and seal the surface
and cause a buildup of nutrients, salts, or heavy metals in
the soil, which could result in poor plant growth and eventually
necessitate abandonment of the irrigation site.
Land Use
Impacts on land use would be most significant for those
alternatives requiring large acreage, i.e., land application
by spray irrigation, discharge to evapotranspiration ponds
and discharge to infiltration ponds. Land proposed for use
under these alternatives is publicly-owned BLM land. Current
uses of the land include cattle grazing, hunting and other
recreational uses. Conversion of BLM land for spray irrigation
or infiltration ponds would preclude present land uses for the
life of the project. Under the evapotranspiration pond
alternative, secondary benefits could be provided by allowing
public access for hunting, bird watching, etc.
Under the no-action alternative, no direct impacts on
land use would occur.
Odors
Malodors resulting from discharge of effluent by any
of the five main disposal alternatives are anticipated to be
minimal. The secondary treatment process should remove most
of the organic matter that might produce odors in decomposition.
For disposal alternatives centered in or near Site;E, the
remoteness of the site should also reduce the potential of
objectionable odors reaching populated areas.
Under the no-action alternative, any odors generated by
effluent disposal would have a greater impact due jto the
close proximity of the existing treatment plant tcj residential
areas.
Noise
Some noise would be generated by disposal facilities for
all alternatives and by truck traffic serving the new treatment
plant. However, due to the remote location of Site E from
developed areas, the impact should be negligible.
102
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Under the no-action alternative, continued operation of
the present treatment plant and disposal facilities, coupled
with increasing residential development in surrounding areas,
would probably result in increased complaints about noise
from heavy truck traffic serving the treatment plant.
Aesthetics
Under the subsurface disposal alternative, probably the
only adverse impact on aesthetics relates to the drinking of
groundwater in an area where sewage effluent is entering the
groundwater aquifer. A series of disposal wells or infil-
tration ponds would have little adverse visual impact.
Effluent disposal to the Deschutes River, particularly
in summer, would probably cause growth of algae on rocks in
the river bed below the point of discharge, a condition that
could be considered aesthetically displeasing.
Discharge of effluent to a series of evapotranspiration
ponds developed as wildlife habitat should be aesthetically
pleasing. Wetland vegetation developed amidst desert terrain
would constitute a beneficial visual impact.
The impact of a spray irrigation system on aesthetics
should be minor. The spray irrigation system would resemble
irrigation systems presently used in the Bend area. The
remoteness of Sites E and F and planned buffer zones surround-
ing each site should reduce any adverse visual impacts.
Under the North Unit Main Canal disposal alternative,
addition of nutrients to the canal and reservoir in summer
could have adverse visual effects through an increase in
production of algae and aquatic plants.
Archeology/History
Two sites of historical significance are found within
the project area and could be affected by several alternative
methods of effluent disposal. The historic Huntington Wagon
Road crosses the northwest corner of Site E (Figure 6-6).
It is felt by some local authorities that the road was also
used by the Meek Wagon Train in 184 5. The road has been
nominated as the Meek Trail to the National Register by the
BLM, Prineville District. That nomination is still pending.
It is projected that the Huntington Wagon Road would not be
adversely impacted by the land application by spray irrigation
alternative. This area of Site E is characterized by extensive
rock outcrops, which would be unsuitable for development as
irrigated cropland.
103
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o
FIGURE 6-6
HISTORICAL ROADS IN THE! PROJECT AREA
A
u
A
NEW TREATMENT
PLANT
- L EGEND -
HISTORICAL ROAD
BEND
-------
A second road of historical importance passes through
Sites E and P (Figure 6-6). This is the Prineville-Bend
Wagon Road. A nomination to the Oregon State Inventory of
Historic sites has been filed for this road. The alternatives
involving effluent disposal via land application by spray
irrigation, infiltration ponds and evapotranspiration ponds
could adversely impact this road.
A number of archeological sites containing cultural
material occur on Si-f-e E. Construction of a spray irrigation
system could adversely impact these sites.
Resource Consumption
Resources consumed during operation of each disposal
alternative includes, where appropriate, primary energy to
operate the treatment plant, the filtration system and pump
effluent to the disposal site and chlorine to disinfect the
effluent. Secondary energy consumption relates to energy and
fuel required to manufacture and transport the chlorine used
in the treatment process. Figures 6-7 and 6-8 compare annual
primary and secondary energy use, respectively, for the five
major alternatives. The land application by spray irrigation
alternative would require the greatest primary energy use due
to energy needs for pumping effluent to spray irrigation
systems. Both the infiltration pond and evapotranspiration
pond alternatives would require no primary energy use because
effluent would be conveyed by gravity flow to the disposal
point. Secondary energy usage would be lowest for both sub-
surface disposal via drill holes and discharge to the North
Unit Main Canal.
No additional resources would be consumed under the no-
action alternative.
Monetary Costs
Present Worth. Estimated present worth values of the
major effluent dispopa) alternatives are compared in
Figure 6-9. Present worth values include initial costs of
facilities and construction, equipment replacement, annual
operation and maintenance minus salvage value at the end of
the project. The evapotranspiration pond alternative would
have the highest present worth value of over $28,000,000.
Land application by spray irrigation would also be costly at
over $24,000,000. The least costly alternative would be sub-
MjrfacG disposal via drill holes at approximately $2,600,000.
105
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FIGURE 6-7
PRIMARY ENERGY USE
- LECZTAID
^ 1980
1990
M 2000
fc
:*n
$3
I
;;
DRILL HOLE
INFILT.
PONDS
SUBSURFACE
DESCHUTES
RIVER
EVAPOTRANS.
PONDS
LAND
APPLICATION
NORTH UNIT
MAIN CANAL
MAJOR ALTERNATIVES
106
-------
FIGURE 6-8
ESTIMATED SEGOMDA^Y EfcSESW
REQUIREMENTS
30 T
- S.SGSMD -
£2 ELECTRICAL ENERGY
~ fuel
28-
26-
24-
22-
20-
13-
16-
10-
12-
10-
8-
6-
4-
2-
0-
DRILL HOLES
SUBSURFACE
INFILT DESCHUTES EVAPOTRANS LAND NORTH UNIT
PONDS RIVER PONDS APPLICATION MAIN CANAL
MAJOR ALTERNATIVES
107
-------
FIGURE 6-9
ESTIMATED PRE SEMT WORTH VALUES
28-
26-
24-
«/> 22"
z
o
_l
-J 20-
£
a**
¦ 18"
UJ
—I
5 16-
S .H
a;
a.
12-
10-
o
ui
t—
< 8-1
6-
4 -
2-
_Vl
j v/k
i
DRILL HOLE INFILT
PONDS
SUBSURFACE
I
%
Vs.
\
DESCHUTES EVAPOTRANS LAND
RIVER PONDS APPLICATION
NORTH UNIT
MAIN CANAL
MAJOR ALTERNATIVES
108
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Modifications of year-round discharge to the North Unit
Main Canal to avoid winter discharge, i.e., combining irri-
gation season discharge to the canal with winter discharge
to: 1) the subsurface via drill holes or infiltration ponds;
2) the Deschutes River; or 3) winter storage, would have
present worth values ranging from $3,424,000 to $8,445,400.
Combined canal and drill hole disposal would be least costly.
In the event that the land application by spray irri-
gation or evapotranspiration pond alternatives would be
eligible for an additional 10 percent grant funding by the
EPA as innovative or alternative technologies, present worth
costs of these alternatives would be reduced to a substantial
degree.
No additional costs would be generated under the no-
action alternative. However, if the no-action alternative
was adopted, monies expended for construction of the new
treatment plant on Site E would essentially be wasted.
User Costs. Costs presented here are for the effluent
disposal system only. However, to gain a perspective of the
total user charges to be expected, an approximate value of
$8.25 per month per single family home was computed for
wastewater collection and treatment. This value was computed
by assuming full federal participitation (75 percent) for the
treatment plant and sludge handling system and no participation
for the sewer system. This amount should be added to the
monthly charges presented to obtain the approximate total
monthly charge per home. The local annual cost analysis is
an estimate of the probable cost individual homeowners would
have to pay per month for each alternative if it was
constructed. The results of this analysis are presented in
Figure 6-10. As would be expected, the evapotranspiration
pond alternative would have the highest user cost of $6.39/
month. The least costly alternative to the user would be
subsurface disposal via drill holes at $0.54/month.
As stated 'jreviously, user costs for the evapotranspi-
ration ponds ard land application by spray irrigation alter-
natives would 'oe reduced if these alternatives become eligible
for additional EPA funding.
Under the no-action alternative, there would be no
additional costs (other than inflation) to Bend residences
for sewage effluent disposal.
109
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X
z
o
UJ
£
o
cc
UJ
a.
640
6 20-
5 80-
5 20-
4 80-
440"
400"
3C0-
3.20-
O 2 so-
ar
*x
a:
UJ
in
=3
2 40-
2 00-
I 60-
I 20-
80-
40-
I
I
I
^ 1
DRILL HOLE INFILT
PONDS
SUBSURFACE
DESCHUTES
RIVER
NOTE USER CHARGES ARE FOR
THE EFFLUENT DISPOSAL
SYSTEM ONLY ADD §8 25/
MONTH FOB SEWAGE
TREATMENT TO OBTAIN
TOTAL. COST PER HOUSEHOLD
FOR SEWAGE TREATMENT
AND DISPOSAL.
w
EVAP0TR ANS
PONDS
LAND
APPLICATION
NORTH UNIT
MAIN C&NAl
MAJOR ALTERNATIVES
110
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Monthly user costs of implementing modifications to year-
round North Unit .Main Canal Discharge would range from $0.69
to $1.74 per connection. The combination of canal and drill
hole discharge would be least costly.
Other Secondary Cost Impacts. Significant increases in
costs of controlling aquatic weeds in the North Unit Main
Canal system could result from discharge of effluent into the
canal at Bend. The North Unit Irrigation District has a
severe and continuing problem controlling aquatic weeds in
their main canal and laterals. The District is obligated to
maintain capacity to deliver water to its users and assure
acceptable water quality. Excessive amounts of aquatic plant
debris reportedly clog structures, turnouts, head ditches,
sprinkler screens and heads and siphon tubes.
Projected use and costs of aquatic herbicides by the
District in 1979 is shown in Table 6-5. The total estimated
cost of herbicide use is $19,7 05. Costs of labor, equipment
and overhead for application of herbicides is generally equal
to at least their purchase price. Thus, the total cost of
aquatic weed control in the North Unit Irrigation District
should be about $39,400 in 1979 (R. Vissia, U. S. Bureau of
Reclamation, letter to EPA dated November 13, 1978).
It has been estimated by the Bureau of Reclamation that
addition of the City of Bend effluent to the canal system
would double or triple the aquatic ueed problem. A dou'bled
aquatic weed control program would cost the District ad
additional $40,000 annually at present day dollars.
Other secondary cost impacts to the North Unit Irrigation
District would be related to maintenance of the canal structure.
Damage to the structural integrity of the canal could 'poten-
tially occur during winter effluent discharge to an empty canal.
Other irrigation districts in the project area that commonly
have winter runs in their canals to allow domestic cistern
filling, experience maintenance problems from ice buildups.
With an average effluent flow of 9 cfs from a 6 mgd capacity
treatment plant and an estimated 11 percent seepage l9ss, water
depth in the North Unit Main Canal Would be only about 2 to 3"
inches. However, it has been reported that ice buildups from
flows as low as 10 cfs can result in structural damage to
project area canals (Wagner, pers. comm.). Actual costs of
increased canal maintenance, however, have not been estimated.
Additional potential secondary cost impacts associated
with effluent discharge to the North Unit Mam Cannl relate
to legal liability of the Irrigation District in the event
that any person or his/her property is adversely affected by
canal ¦..•tter containing-effluent contaminants. There is
111
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Table 6-5
PROJECTED 197 9 USE AND JOSTS OF AQUATIC
HERBICIDES - NORTH UNIT IRRIGATION DISTRICT
Material Amount $ Cost
Xylene
10,500
gal.
7,004.00
Emulsifier
165
gal.
937.00
Magnacide H (acrolein)
832
gal.
9,568.00
Copper sulfate
6,000
lbs.
2,196.00
TOTAL
19,705.00
Source: R. Vissia, Bureau of Reclamation, letter to EPA
dated November 13, 1978.
11?
-------
potentially no limit to the magnitude of this cost impact;
however, it should be noted that any person(s) bringing suit
against the District for alleged personal harm would have to
prove conclusively that canal effluent contaminants caused
their disorder. The probability of proving such a case
during the irrigation season would be highly unlikely taking
into account existing canal water quality and the unlimited
sources by which contaminants could make their way into the
canal system. In winter, however, no dilution of effluent
would occur resulting in a greater likelihood that any harmful
effects to persons coming in contact with the effluent stream
could be more easily proved. Costs of liability insurance
for the District were estimated to be approximately $1,000
annually (QECON, Design Definition Memorandum #10).
Discharge of effluent to the North Unit Main Canal
system could also have a secondary economic impact on the
private resort at Haystack Reservoir. Any adverse changes
in the quality of water in the reservoir (eutrophication
leading to increased algae and aquatic plant growth) could
reduce recreational use of the reservoir, thus reducing
income of the resort. The magnitude of this potential adverse
impact on the resort, however, cannot be estimated.
For those alternatives involving potential impact on
drinking water supplies, including the no-action alternative,
secondary cost impacts could be associated with necessity to
provide alternate sources of drinking water for affected
users. Under the subsurface disposal and no-action alternative,
contamination of groundwater supplies in the Bend area would
require that all affected wells be deepened to utilize the
isolated deep artesian aquifer. Costs associated, with this
requirement would depend on the number of contaminated wells
and could be highly significant. Under the Deschutes River
discharge alternative, domestic use of river water could be
prohibited requiring private users and the City of Redmond to
find alternate sources -- also a potentially significant cost
impact of unknown magnitude. Urj?ler the North Unit Main Canal
disposal alternative, the City of Madras nught al'so be required
to develop an alternative source to canal water use in summer.
An additional city well could be drilled for this purpose at
an estimated cost of $800,000 with annual maintenance costs of
$15,000 (BIICON, Design Definition Memorandum #10).
Under the no-action alternative, an additional secondary
cost impact of unknown magnitude would be associated with poten-
tial effluent overflow from the lava tube presently used for
subsurface disposal. Backup of effluent could result in con-
siderable damage to residential areas surrounding the trcatr-or.t
plant.
113
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Secondary costs would also be associated with the ability
to expand the chosen effluent disposal alternative in the
future. The population in the Bend service area is forecast to
increase throughout the 20-year planning period. Associated
with an increase in population would be- an increase in waste-
water flows which would have to be accommodated by expanding the
treatment and disposal facilities. The disposal alternative
that could be expanded using the least number of facilities
and would also be the least land-consumptive were considered
to be easiest and least costly to expand. Accordingly, the
ranking is as follows:
1. Drill hole disposal, North Unit Main Canal discharge,
Deschutes River discharge.
2. Infiltration ponds.
3. Evapotranspiration ponds, land application by spray
irrigation.
Mitigation Measures
To reduce potential adverse impacts of the alternative
methods of effluent disposal, the following mitigation
measures are proposed.
Subsurface Disposal - Drill Holes. Subsurface disposal
of effluent, particularly in the case of discharge to drill
holes, will be accompanied by a monitoring program under
which appropriate groundwater bodies will be sampled periodically
(EPA letter tc DEQ, 3-16-78). However, mitigation through
a monitoring program has not been defined at this time. A
description of a potential monitoring program follows. Sampling
well stations would be positioned so as to intercept any
effluent-related groundwater flow before it moves beyond
site boundaries. Any present and future wells for some distance
in the general direction of groundwater flow should also
be included. Other wells adjacent to the site should also
be sampled. Sampling might be at 3-morth intervals initially
and adjusted later if appropriate. The static piezometnc
surface should be monitored before each sampling.
Such water quality surveillance should commence at least
1 year prior to actual subsurface effluent disposal to provide
a background data base. Analytical quality determinations
would be designed to detect measurable amounts of effluent.
It is tentatively considered that a minimum of three water
quality monitoring wells might be adequate, one about 1/4
mile north of the disposal point and two about the same
distance inside the north site boundary downstream, spread
about 1/2 mile apart. Additional surveillance points may be
in order after analysis of preliminary exploratory data.
114
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Design standards and criteria for subsurface disposal
wells can be determined only after deep drilling exploration
and testing at the project site is completed. Design criteria
would include optimum depth and diameter of the disposal
well(s), depth of casing, number of wells, locations, and
other factors.
Prior to actual discharge of effluent, a program of
subsurface discharge tests using canal water should be
conducted.
At such time as monitoring results indicate impending
contamination of off-site groundwater supplies by subsurface
disposal of project effluent, then a more intensive sampling
program could be initiated to confirm problems and define
them in greater detail. Additional monitoring stations may
have to be drilled. If project operations are clearly shown
to be damaging the usability of groundwater resources, an
alternate method of disposing of plant effluent must obviously
be put into effect.
The potential mitigating circumstance of greatest
importance m this situation is the underlying deep artesian
aquifer. Its existence beneath the general area is reasonably
indicated, but remains to be proven. Being under considerable
artesian head, it is probably noc subject to any significant
contamination from surface sources in this area. Thus, if
the overlying aquifer zone is contaminated by subsurface
effluent disposal this lower zone is presumed to be available
as an alternative water supply source. Therefore, it is
important that the existence of this aquifer in the Bend
area be explored in greater detail.
Subsurface Disposal - Infiltration. A similar monitoring
program should also be implemented for effluent disposal to
infiltration ponds. Ponds should be properly maintained by
discing infiltration sands and soils on a periodic basis to
prevent clogging of the filtering medium. Insect vectors
could be controlled, if necessary, with insecticides.
Discharge to the Deschutes River. To reduce public
health risks to domestic users of Deschutes River water,
advanced wastewater treatment would have to include nitrate
removal, a very costly treatment process. The only other
alternative would be to provide alternate sources of drinking
water for all domestic users below Bend. To determine the
number of affected domestic users downstream, a program would
be necessary to monitor effluent contaminant concentrations
at various points below the discharge point.
113
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To protect the fishery resource, wastewater treatment
would require ammonia and chlorine removal during periods of
low flow in the river.
Discharge to Evapotranspiration Ponds. To reduce public
health risks, insect vectors could be controlled by stocking
ponds with mosquitofish (Gambusia) or by using insecticides.
Initial ponds in the series, as well as the infiltration pond,
could be fenced to prevent public access thereby reducing the
risk of public contact with undiluted effluent. Ponds
further down in the series would have the benefit of more
complete effluent treatment through processes of natural
decay and biological decomposition, thus reducing public
health risks. The pond series should also be designed to
prevent pond stagnation, a result of poor water circulation.
An education program could be implemented to inform the public
of general precautions that should be taken when coming in
contact with sewage effluent.
Land Application by Spray Irrigation. Due to expected
low concentrations of viruses and chemical compounds in the
secondary effluent, combined with the filtrative capability
of the soils and vegetation, contamination of the groundwater
and a resultant public health risk are unlikely. As a safe-
guard, however, test wells should be established and ihonitored.
Monitoring requirements would be much less intensive than in
the case of subsurface disposal. The closest wells on all
sides of the pro]ect site should be monitored. Also, in the
absence of existing wells, monitoring wells should be drilled
to the first usable aquifer encountered. They should be
spaced on 1 mile centers along the northern site boundary,
1/8 to 1/4 mile outside the site. Sampling of these stations
should be quarterly, beginning approximctaly 1 year prior to
project start-up.
Soils and soil water could be monitored periodically to
^determine any deficiencies in crop nutrients or discLOse a
buildup of any substance that could be harmful to crop
production. However, due to the high porosity of soils on
Sites E and F and the expected low concentrations of nutrients,
salts, and heavy metals in the effluent produced at the new
treatment facility, toxic buildups in soils or vegetation is
not expected.
Advanced wastewater treatment u?ing sand filtration,
which would remove essentially all bacteria and viruses, would
substantially reduce any possible health hazards to irrigation
system operators and the general public from pathogenic con-
tamination of water, soils, air or vegetation. Planned buffer
116
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zones of native vegetation approximately 1,000 feet wide
surrounding each irrigation site should reduce aerosol travel.
Low trajectory nozzles would also limit aerosol travel. The
wain, dry climate of the Bend area should effectively reduce
survival of airborne bacteria and viruses.
Mosquito propagation or. irrigation sites could be
controlled by use of insecticides. Such practices, however,
could involve some degree of environmental degradation and
would probably serve only as a temporary solution. Drying
periods between wastewater applications or reduction of
hydraulic loading rates would reduce breeding opportunities
on irrigation sites.
To mitigate wildlife and wildlife habitat losses, if
possible, construction activities should be scheduled to
avoid disturbances during the breeding season, thus reducing
overall losses of nesting birds and some mammals. Adjacent
native habitat could be enhanced through creation of brush
piles, or range management for preferred food plants or
exclusion of cattle.
Discharge to the North Unit Main Canal. To reduce
adverse impacts of canal effluent disposal, a number of
mitigation measures could be implemented. To mitigate public
health risks associated with domestic water use, monitoring
of the Madras water treatment plant could be conducted during
the irrigation season. If contamination was detected, one
or more new water wells could be constructed for the City of
Madras to replace use of canal water in summer.
A public education program could be implemented to
provide information to irrigators and recreationists on
potential health hazards and public health risks of coming
into contact with canal water containing effluent. In
addition, the City of Bend could assume liability for any
claims against the District concerning harmful effects of
effluent discharge into the canal.
To mitigate increased costs to the District for aquatic
weed control, the City of Bend could reimburse the District
for estimated additional expenditures. The only other alter-
native would be to upgrade effluent treatment. AWT processes
providing phosphorus removal would probably be appropriate.
Establishment of a monitoring program would provide valuable
information on pollutant levels in the canal.
117
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Use of the canal in winter for effluent disposal would
presumably require negotiations between the Bureau of Recla-
mation and the North Unit Irrigation District to amend the
present amendatory repayment contract. If winter discharge
was deemed acceptable, a monitoring program, similar to that
described for subsurface disposal, would be appropriate. A
number of test wells'could be drilled near canal seepage
areas to detect any groundwater contamination of perched or
deep groundwater aquifers. Domestic wells located near the
canal could also be monitored periodically. Implementation
of modifications to year-round canal discharge (e.g., winter
storage, winter drill hole disposal) would eliminate any
adverse impacts associated with winter discharge to the canal.
No-Action Alternative. Inasmuch as there is no current
basis for estimating effects on groundwater from continuation
and increases in the present disposal practices, a carefully
formulated surveillance program as well and river sampling
would be needed to alert the community should problems exist
or arise in the future. In the event of the contamination of
water resources by septic tank disposal, it would appear
essential that households adopt alternate wastewater systems,
regardless of cost. New water wells would have to be drilled
to the deep artesian aquifer to replace contaminated wells.
Were the city treatment plant found to be polluting, then the
only apparent remedy would be to upgrade the level of treatment.
Local Short-Term Uses of the Environment vs.
Maintenance and Enhancement of Long-Term Productivity
The present discharge of inadequately treated wastewater
to the subsurface through individual disposal wells represents
a short-term use of the environment that could adversely
affect the long-term productivity of the regional groundwater
aquifer.
All alternatives of effluent disposal could decrease the
potential for contamination of groundwater and public health
risks. Those alternatives not involving direct discharge of
effluent to the subsurface would afford the greatest protection
against groundwater contamination. Several alternatives con-
sidered involve discharge to surface waters and therefore
could be viewed as a trade-off between potential groundwater
contamination and potential degradation of surface water quality,
which would increase public health risks to domestic water
users on the Deschutes River and North Unit Main Canal. Those
alternatives relying on natural vegetative and/or soil systems
for pollutant removal, i.e., infiltration ponds, land appli-
cation by spray irrigation and evapotranspiration ponds should
be most 'reliable in preventing contamination of either ground-
water or surface water-dr*inking supplies.
118
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Adoption of the no-action alternative would allow for
continued subsurface discharge of inadequately treated wastes.
An even greater risk, to public health from groundwater contami-
nation would develop as population growth occurred in the Bend
area.
Irreversible and Irretrievable Commitment of Resources
With all alternatives, except no-action, there would be
minor and major irreversible and irretrievable commitments of
renewable and nonrenewable resources. Significant commitments
of irrecoverable resources, such as building materials, piping,
time and energy would be required during construction of all
alternative methods of effluent disposal. Alternatives
involving extensive land use, i.e., infiltration ponds, land
application and evapotranspiration ponds, would result in
irreversible losses of some wildlife and native vegetation.
Discharge to surface waters could cause irreversible losses
of some game fish.
After construction, operation of each alternative would
require irrecoverable commitments of time, chemicals, energy
and maintenance mc trials. Land application by spray irri-
gation would require the greatest commitment of operational
resources.
Unresolved Issues
As discussed in Chapter 6, no definite conclusions can
be drawn regarding the potential impacts of subsurface effluent
disposal at Site E on groundwater. Results of a recently
completed geologic investigation conducted by BECON on Site E
should provide greater insight into potentials for1 groundwater
contamination (BECON, preliminary draft, Septemberj 1979).
It is anticipated that final results of these studies will
be available for inclusion and evaluation in the fjinal EIS.
119
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Chapter 7
LIST OF PREPARERS
Charles R. Hazel, Ph.D., Vice President, Jones & Stokes
Associates, Inc., Sacramento, California. Project
Manager.
Karen J. Miller, M.S., Jones fi Stokes Associates, Inc.,
Portland, Oregon. EIS Coordinator.
Robert B. Williams, P. E., Culp/Wesner/Culp, El Dorado
Hills, California. Sanitary Engineering.
Robert C. Gumerman, Ph.D., P.E., Principal, Culp/Wesner/
Culp, Santa Ana, California. Sanitary Engineering,
Cost Comparisons.
William C. Ellis, Reqistered Geologist, Certified Engineering
Geologist, Cooper-Clark Associates, Los Altos, California.
Geology and Groundwater.
Robert C. Cooper, Ph.D., Department of Biomedical and
Environmental Health Sciences, School of Public
Health, University of California, Berkeley. Sanitary
Engineering, Bacterial, Viral Analyses of Water
Supplies.
Donald B. Porcella, Ph.D., Associate Director, Utah Water
Research Laboratory, Utah State University, Logan.
Civil Engineer, Nutrient and Eutrophication Analyses.
Garry Stephenson, M.S. Candidate, Department of
Anthropology, Oregon State University, Corvallis.
Archeology and History.
John A. Draper, M.S. Candidate, Department of Anthropology,
Oregon State University, Corvallis. Archeology and
History.
121
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Chapter 8
BIBLIOGRAPHY
Literature Cited
Bend Engineering Consultants. 1977a. City of Bend, Oregon.
Wastewater collection, treatment and disposal facilities;
supplemental Environmenal Impact Assessment. Amendment
No. 1 to Sewerage Facilities Plan.
1977b. City of Bend, Oregon. Wastewater
collection, treatment and disposal facilities. Design
Definition Memoranda Nos. 1-9.
1979. City of Bend, Oregon. Wastewater
collection, treatment and disposal facilities. Design
Definition Memorandum No. 10.
1979. Summary. Subsurface effluent disposal.
Preliminary Draft. September 20, 1979.
Cooper, Clark & Associates. 1979. Geotechnical jjjivestigations,
Bend, Oregon. July 16, 1979.
Krone, R., G. Butler and C. Hodgkinson. 1958. Movement of
bacteria through porous medium. Sew. and Ind. Wastes 30:1.
I
Lance, J. C., and C. Gerba. 1977. Nitrogen, phosphate and
virus removal from sewage water during land >infiltration.
Prog. Water Technology 9:157. Pergamon Press, Great
Britain.
Oregon. Department of Environmental Quality. 1?7 6. Oregon
air quality report, 1976.
. 1977. Assessment*of stream quality'in Oregon
based on evaluation of data collected in the 1976 stream
sampling program.
Orlob, J., and R. Butler. 1955. An investigation of sewage
spreading on five California soils. Tech. Bull. 12,
I.E.R. Series 37; S.E.R.L., Univ. of C\, Berkeley.
Pound, C., and R. Crites. 1973. Wastewater treatment and
reuse by land application. Vols. I. II. U. S. Environ-
mental Protection Agency. EP.\ 606/2-73-0062, b.
Preceding page blank
123
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Sceva, J. 1968. Liquid waste disposal in the lava terrane
of central Oregon. U. S. Dept. of Interior, Federal
Water Pollution Control Admin.
Stevens, Thompson, and Runyan, Inc. and Tenneson Engineering
Corp. 1976. Sewerage facilities plan. City of Bend,
Oregon. Vol. I, II.
Storet. 1978. Water quality data for Oregon. Available
from the Water Pollution Control Lab., Dept. of
Environmental Quality, Portland, OR.
Thurston, R. V., et al. 1978. Review of the E. P. A. redbook:
Quality criteria for water. Preliminary edition. Water
Quality Section, American Fisheries Society.
U. S. Bureau of Reclamation. 1972. Deschutes project,
central division, Oregon. Potentials for expansion and
improvement of water supplies.
U. S. Department of Agriculture. 1958. Soil survey for
Deschutes County, Oregon.
U. S. Department of Commerce. 1977. 1974 census of
agriculture, Oregon state and county data. Vol.1, Part 37,
U. S. Environmental Protection Agency. 1977a. Waste disposal
practices and their effects on groundwater. Report to
Congress.
1977b. Irrigation wastewater disposal well
studies - Snake Plain aquifer. Ecoloqical Research Series,
EPA 600/3-77-071.
Woodwell, G. M. 1977. Recycling sewage through plant
communities. Amer. Scientist 65(5):556-562.
Personal Communications
Carter, G. 197 8-9. Oregon State Department of Environmental
Quality. Portland, OR.
Edwards, R. 1978. City of Redmond. Redmondr OR.
Estes, B. 1978. Oregon State Water Resources Department.
Salem, OR.
Fies, T. 1978. Oregon State Department of Fish and Wildlife.
Bend, OR.
124
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Miller, B. 1978. City of Madras. Madras, OB.
Ossenkop, D. 1979. U. S. Department of Transportation, Federal
Aviation Administration. Seattle, WA.
Paterno, p. 1979. Bureau of Land Management. Prmeville, OR.
Perry, N. 1978. Oregon State Water Resources Department
Salem, OR.
Sceva, 3. 1979. U. S. Environmental Protection Agency.
Seattle, WA.
Schwart2, E. 1978. Oregon State Department of Fish and
'Wildlife. Prineville, OR.
Shimek, R. 1978. Oregon Department of Environmental Quality.
Bend, OR.
Wagner, R. 197B. North Unit Irrigation District. Kadrcs, OR.
Williams, E. 1979. U. S- Bureau of Reclamation. Boise, ID.
Agencies and Organizations Contacted
Bend, (City of), Oregon
J. Donahue
M. Elmore
A. Johnson
Bend Engineering Consultants
P. Case
N. Dempsey
W. Lapsley
G. Lynch
Century West Engineers
J. Beemer
T. Cooper
M. Hanley
D. Newton
Madras (City of), Oregon
B. Miller
125
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North Unit Irrigation District, Madras, Oregon
R. Wagner
Oregon, Department of Environmental Quality
Bend:
T. Hall
R. Shimek
Portland:
G. Carter
Oregon, Department of Fish and Wildlife
Bend:
T. Fies
Prineville:
E. Schwartz
Oregon, Water Resources Department
Bend:
R. Main
Salem:
B. Estes
K. Mathiot
N. Perry
Redmond (City of), Oregon
R. Edwards
U. S. Bureau of Land Management, Prineville, Oregon
P. Paterno
N. Steggell
M. Ziegler
U. S. Bureau of Reclamation
Salem, Oregon:
R. Kannasto
Boise, Idaho:
C. Daly
G. Lee
F. Oliver
L. Persson
N. Stessman
V. Temple
E. Williams
126
-------
U. S. Environmental Protection Agency, Seattle, Washiryton
B. Mullen
J. Scevn
H. Scott
U. S. Federal Aviation Administration
Seattle, Washington:
D. Ossenkop
Salem, Oregon:
R. CostellG
V. S. Forest Service
Bond, Oreqon:
L. Chitwocd
Prmevillc (Crookea River National Grassland), Orccron:
C. Hylton
U. S. Geological Survey, Portland, Oregon
J. Gonthier
127
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Chapter 9
APPENDICES
129
Preceding page Wank
-------
Appendix 1
SUBSURFACE DISPOSAL OF EFFLUENT
VIA INFILTRATION PONDS
Culp, Wesner and Culp
July 1979
Physical Facilities
This alternative requires that all effluent be discharged
on a year-round oasis to an infiltration/percolation pond area.
Treated water would be delivered to the spreading ponds by
means of an estimated 42-inch diameter gravity flow pipe.
Once at the ponds, the water would be distributed into four
cells and allowed to percolate through the surface media to
the substrate.
Construction of the infiltration pond would require the
construction of approximately four cells in the infiltration
area. The cells would be separated by dikes or berms. The
berms would have the approximate configuration as shown in
Figure 1. Native materials would be used to construct the
berms which would be about 4 feet high with a crest width of
6 feet. Some sand and gravel may be imported to provide a
minimum percolation depth of 3 feet. Percolation of 6 MGD
continuously would require wetting 85 acres. This 85 acres
would be sufficiently large to accommodate the average flow
as well as a peak flow 20 percent greater than the average
flow.
Operational Characteristics
The infiltration ponds would be operated year round.
To maintain good infiltration characteristics, the cells would
need to be cycled such that they are wet for an equal period
of dry time. Additionally, over a period of time the infil-
tration rate may diminish. Consequently, the basins will need
to be disked or rototilled annually. It is also estimated
that the berms may require major repair at 10-year intervals.
Other maintenance that would be required includes periodic
cleaning of the transmission pipe and repair of roads and
fences.
130
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Hydrologic Disposal Characteristics
Percolation and soils data were gathered by a representa-
tive of Cooper-Clark and Associates of Palo Alto, California.
The data were gathered on July 17, 18 and 19, 1979 and a report
was prepared discussing the results and implications of the
data gathered.
Based on preliminary data, the clear water infiltration
rate was measured to be an average of 7/8 inch per hour or
147 inches per week. However, use of wastewater substantially
reduces the amount of water that can be percolated. For pur-
poses of this study, a rate of 15 percent of the clear water
rate or 22 inches per week was used to determine the land area
required. A value of 5-25 percent of the clear water rate
is recommended by EPA. Local evaporation records were used
to determine the amount of evaporation that might be experienced.
The evaporation rate was found to be negligible compared to
the percolation rate. Allowing for peak flows and reduced
infiltration capacity, about 85 acres will be needed to dispose
of the wastewater.
Treatment Reliability
The treatment reliability would be improved over secondary
treatment. The soils would remove a great proportion of any
suspended solids remaining after secondary sedimentation.
The design should include assurance of a minimum of 3 feet
of percolation media. It has been demonstrated that 3 feet
of media is capable of reducing pathogenic organisms that may
be remaining.
131
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FIGURE 1
SCHEMATIC DIAGRAM
OF INFILTRATION POND ALTERNATIVE
-------
Appendix 2
EFFLUENT DISPOSAL VIA EVAPOTRANSPIRATION PONDS
Culp, Wesner and Cuip
July 1979
Physical Facilities
This alternative proposes to dispose of treated wastewater
by discharging to a series of artificial wetland ponds or
marshes. To supplement the ponds, infiltration basins would
be provided to dispose of the treated effluent during peak
flow periods and for winter flows. Since the wetlands would
be primarily used to dispose of the water, the ponds would
need to be designed as evaporation ponds with sufficient capa-
city for water storage. The basins would be sized to evaporate
about 3 feet of water per year during the months of April
through October. This would dispose of about 60 percent of
the annual wastev/ater flow. The balance of the flow would
be placed in infiltration basins designed the same as the
basins for subsurface disposal via infiltration basins.
As seen in Figure 1, the marshes would be aligned in
series with the infiltration basin in parallel. Flow to the
first marshes and the infiltration basin would require gravity
flow through a pipeline. Subsequent downstream flow would
utilize lined trapezoidal canals. Natural depressions would
be utilized as much as possible for embankments. Artificial
embankments, or berms, would be constructed the same as for
infiltration basins. The marshes would have an average depth
of 9 feet and would be lined with bentonite to minimize water
loss through the bottom. The marshes would be stocked with
marsh plants native to the Bend area. Fish would be stocked
in the ponds to reduce the potential mosquito population.
Operational Characteristics
The proposed system could be operated year round. The
marshes would be fed water from April through October, while
the infiltration basins would receive peak flows and winter
flows. The infiltration basins would be operated in the same
manner as for subsurface disposal via infiltration basins.
133
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The marsh ponds would requite a minimum of maintenance.
Periodically, the plants growing in the marshes would need
to be harvested. The resulting plant debris could either be
disposed in a landfill, composted to be used as a soil amend-
ment, or processed as cattle feed.
Limitations experienced with wetlands include poor plant
growth during winter, loss of duckweed from blowing winds,
and mosquito growth. All can be controlled by proper marsh
management. The most significant limitation with the wetlands
as proposed is the salt buildup in the residual water as the
evaporation occurs.
Hydrologic Disposal Characteristics
Design of the wetlands is essentially the same as a design
for evaporation ponds. It is estimated that the wetlands would
experience about 3 feet of evaporation during the application
periods. Thus, maximizing the evaporation, the wetlands would
require 1,270 acres.
The ponds could dispose of about 3,940 acre-feet of waste-
water during the year. The balance (2,780 acre-feet) would
be discharged to the infiltration basins. It is estimated
that the infiltration basins will require 35 acres.
Treatment Reliability
Wetlands can produce a higher quality effluent. Test
units operating artificial marsh facilities have reported
significant reductions in BOD, suspended solids, ammonia,
nitrate, phosphorus and coliform organisms. The quality of
water produced from wetlands treatment has been considered
to be much higher quality than secondary effluent.
Treatment using marshlands has some limitations. Salt
accumulation and low temperatures could hamper plant growth,
thus reducing nutrient removal.
Modifications for Cost Reduction
Substantial cost savings could be realized by using the
wetlands as a treatment process rather than a disposal method.
If this were done, any number of acres could be used but optimum
treatment could be achieved using 150 acres. Another method
of reducing' the cost could be realized by using the downstream
ponds as percolation basins. Regardless of which method is
chosen, staging the construction as capacity is needed could
reduce th'e immediate cost.
134
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u
Ln
FIGURE 1
SCHEMATIC DIAGRAM OF THE
EVAPOTRANSPI RATION POND ALTERNATIVE
0
0
E3
e
D
£3
TOTAL WETLANDS AREA
1270 ACRES
TOTAL l/P BASINS AREA
3S ACRES
-LECfA/D-
A- WETLANDS POND
B-INFILTRATION BASINS
C -PIPELINE (APPROX. 42"
D - OPEN CANAL
OIA.
TYPICAL WETLANDS CROSS SECTION
2 / SLOPE
,3'FREEBOARD
¦ 3 / SLOPE INSIDE
12
BERM
Mton Watar Dtpfh 9'
Maximum Wattr Dtpfh 12'
EDGE OF
NATURAL
DEPRESSION
i AH Wtttid Surfacts Stolid
With 6-12" Of Btnfon'ift
-------
NATIONAL INTERIM PRIMARY DRINKING WATER REGULATIONS -
MAXIMUM CONTAMINANT LEVELS
(Federal Register 40(248), 1975 and 41(133), 1976)
Sut^art Q—t&aSinufft Contomlncnt Uwsts
114I>11 Stialmnro ccoun-lnnnt levels
tea Isareacis cbualtak*
(*) Tbe maximum ccatnmlnnnt level
for Bltnta la applicable to both commu-
nity wsur eywesa and non-coauaunity
water ayatcma. Tha lavalo lor tho other
tnorcuio chemicals apply only to con*
rmmity wata? nys terns. Compliance -nth
mnrlrmim contaminant levels for lnor-
Bania chemicals is c&lculatod pursuant to
1141.23.
(b) Hie following are tfc# maximum
oonumtrrm lords for inornate chtml-
call other than fluoride •
Coat,
mUUeram*
Ocatamlmuit par hut
Amnio 0.0J
Banum i.
Carnnium —. o. oio
CbrenUum .. 0. OS
Uxd — 0 08
Mercury 0.003
Nitrate (m N) ... 10.
Salanlum 0 01
Mllipr 0.03
(e) When the annual averaae of the
mnrlirnim dally air temperatures lor tha
location la which ths community water
system Is situated la tho following, the
mrmlmiKn contaminant leveU tor fluoride
ere:
Tvntmian lavti
D*m«« iVfn-n CrUlus mlUlmnw
pcriiitr
Oleadtefav I? 0«dbabv 14
111 W 14 0 11
u?toi7« zo
GLSlo TU.*._ 17 T to 31 I LB
ra?(«nx. «jui u i •
TP J locals 3JUXU L«
| 141.13 Masimua eootaminanl l«v«U
for organic chemlcala.
Tho following an tho maximum con-
taminant Iovcla for ortranle eheuicals.
They apply only to community water
an tenia. Compliance with tnnxlmum
contaminant lovels for organic chflmlrnln
Is calculated pursuant to f 141.24
tlMl,
niUUyrof7i»
ptrltttr
(•) dlortAfttod brdrocaxbo&o:
Bitina (UJ.OQ. ;o>boucaioro- 0 Q003
0,7^90x7-1 4. UJ 6.7 8 8* octft"
b?sya
1.4 -D. (3,4-..iehlorcp!»«aoiyie«- 0 1
lie Kid I
I.M-TP Sllrn (3 4 3-THcblero- 0 01
paaooxypropiooic acid)
f 141.13 Maximum contaminant levela
for torbldlty.
The maximum contaminant levels for
turbidity arc applicable to both commu-
nity TTater systems (tad non-community
wat«r systems using surfac- water
sources in whole or la part. The maxi-
mum contaminant levels for turbidity
In drinklnfl water, measured at a repre-
sentative «ntry polatta) to the distribu-
tion systeiu. are:
(a) One turbidity unit (TOT. aa de-
termined by a monthly averago pursuant
to 1 141.22. except that &vo or fewer
turbidity unite may bo allowed U tho
ouppller of water can demonstrate to the
Stftta that the higher turbidity does not
do any of the following:
<1> Interfere with disinfection:
(2) Pre\ent maintenance of an effec-
tive disinfectant agent throughout the
distribution system; or
(3) Interfere with microbiological
determinations.
(b) Five turbidity units based on an
averaae tor two consecutive days pursu-
ant to 1141.23.
J 141.14 Maximum microbiological con-
taminant Ict»U.
The maximum contaminant levels for
coUform bacteria, applicable to com-
munity water systems and non-com-
munity water systems, are as follows:
(a) When the membrane filter tech-
nique pursuant to 1 141.21(a) Is used,
the number of collform bacteria shall
not exceed any of the following.
(1) One per 100 milliliters as tho
arithmetic mean of all samples examined
per month pursuant to i 141J1 lb) or
:
(2) Four per 100 milliliters In more
than one iample when less than 20 are
examined per month; or
(3) Four per 100 milliliters In more
than five percent ot tho samples when
20 or more are examined per month
(b)(1) When the fermentation tube
method and 10 milliliter standard por-
tions pursuant to I 14121(a) are used,
collform bacteria shall not be present In
any of the following:
(1) more than 10 percent of tne por-
tions In any month pursuant to I 141.31
(b) or (c>.
For community or non-community
systems that ire required to sample at a
rate of less than 4 per month, com^.l-
ance with paragraphs (a), (b)(1). or
tb) (2) of this section shell be baaed upon
oampllno during a 3 month period, ex-
cept that, at tha discretion of the State,
compliance may ba based upon saopUns
during a ono-i onth period.
9 141.13 MfiaJaaa contaminant lerela
For mjlui»2*6, fodlowa ??8» ind
U«Ma alpha paittck redfeetrirlty In
eoaully veto eydraa,
Tha fallcurlnff aro the maximum con-
tamlnnnt levels for rsdium-228, nullum-
sat, and gro-s alpha particle radio-
activity:
(a) Combined radlum-235 and radl-
mn-ZZS—S pCl/1.
(b) Orooo alpha particle activity (lu-
eluding radlum-228 but excluding radon
bod uranium)—IS pCl/l.
Q 141.16 Maximum contaminant lercta
for botn portld* and photon rttuK*.
actlnly frota aaa-asdc radionu-
clides m eommooity water eyateuu.
(a) The average annual concentration
of beta particle and photon radloccttviiy
from man-made radionuclides In drink-
ing water shall not produce an annuil
dose equivalent to tha total body or ar.y
Internal organ greater than 4 mlUlrem/
year.
(b) Except for tha radionuclides listed
la T&blo A. the concentration of man-
mado radionuclides causing 4 mrem total
body or organ dose equivalents shall be
calculated on the basis of a 2 liter per
day drlnJctair water Intake using the ICS
hour data listed In "itasimum Pcrmlt-
sible Body Burden* and Maximum Pe~-
musfola ConemtraWm of Radionuclide
s s lofal frndy or orynn
tfoM o 1 4 Arcm/fr
RtdtoftnclM*
CmfaeJorfM
pCl
par Um
trtttfvi
. Tbodr.
vx 000
lowmun^ft,
. Boo* (&MTQ* .
1
Subpart C—Mcnito<(ng and Analytical
Requirements
9 141.21 Mlcrobioloficiil contaminant
•ampllnf and anolj^lcai rt*iuii**
Bicnta.
(a) Suppliers of water for community
water systems »nd r.on-commumty wsier
systems shall anal>:e for collform bac-
terj for the purpose of determining
compliance with f 141 14 Analyses shall
be conducted In accordance with the an-
alytical recommendations set forth in
"Stjndard Methods for the Examination
of Water and Wastewater." American
Public Health Association. 13th Edition,
pp (62-488 »xceot List a standard sam-
ple size shall ba employed. The standard
sample used In the membrane filter pro-
cedure shall be 100 milliliters
136
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Appendix 4
OREGON STATE HEALTH DIVISION WATER QUALITY STANDARDS -
OREGON ADMINISTRATIVE RULE 333-42-210
333-142-210 ( 1) Scope: The water Quality
stendards apply to water leaving the source
facilities and to water entering the user's
service pipeline.
(2) Chemical Quality:
(a) Routine Analysis:
Contaminant Max. flUovablg
Concentration in ma/1
Alkalinity (Total as CaCOj) N.A.
Calcium N.A.
Chloride 250.0
Copper 1.0
Fluoride 2.0
Hardness (an Ca CG3) N.A.
Iron 0 30
Manganese 0.050
Magnesium N.A.
Nitrate (as H) 10.0
Nitrite (as N) N.A.
pH N.A.
Silica N.A.
Sodium N.A.
Sulfate 250.0
Solids (Total) 1000.0
Solids (Volatile) N.A.
Zinc 5.0
"N.A." means "not applicable" as applies
to a maximum concentration but the deter-
mination shall be included in the anal-
ysis.
(b) Special Analysis:
When any of the following contaminants are
suspected or known to be present in a con-
centration of 50j or Bore of the following
limits, the analysis for the questioned
contPTinant shall be 'performed along with
the routine chemical analysis:
Cqpta"unant
Hax¦ Allowable
Concentration in ng/1
Arsenic 0.050
Barium. 1.0
CacHiun 0.010
Chromun 0 .050 *
Cyanide 0.20
Lead 0 05H
Mercjry 0.0020
Orijanics:
Alkyl Benzene Sulfonate (ABS)... .0..50
Carbon Chloroform Extract (CCE)..0.20
Phenols 0.0010
Selenium 0.010
Silver 0 050
(c) Miscellaneous: If there is reason to
believe that the water contains any chem-
cals of known deleterious physiological ef-
fects or nuisance properties, then addi-
tional tests shall be conducted for these
chemicals. If the Division finds such chera-
icals in excessive concentrations, then the
concentration shall be lowered to an ac-
ceptable level or a new, acceptable source
ahall be developed.
(d) Routine Chemical Sampling Freouency
Requirements: The water purveyor shall have
a sample of finished water collected and
analysed for each source at such a time as
to represent condition" of average water
quality as follows:
(A) For a surface water, infiltration
gallery or shallow well source, an initial
analysis before July 1, 1978, and there-
after annually;
(B) For deep well, an initial analysis
before July 1, 1979» and thereafter at
three year intervals.
(e) The Division may require that addi-
tional chemical sampling and analysis be
performed when it is known or suspected
that substandard water quality has occurred
in the water system. (When any chemical
contaminant is exceeded refer to subsection
(8) below.)
(3) Physical Ouality:
(a) The maximum allowable contaminant
level of turbidity is one formazin turbid-
ity unit for filtered water supplies. Up to
five units may be allowed on unfiltered
supplies if the water purveyor can demon-
strate to the Division that the higher tur-
bidity level does not:
(A) Interfere with disinfection; and
(B) Prevent maintenance of an effective
disinfectant agent throughout the distribu-
tion sv3ten; and
(C) Interfere with microbiological deter-
minations .
(o) Sand shall not ba present ir. amounts
greater than 2.0 mc/1.
(c) Color sKall not exceed 15 units.
(d) Odor shall not exceed the threshold
odor nunber 3-
(e) The water purveyor shall have a dail/
sanple of finished water collected and
137
-------
Appendix 4 con't.
i 11-/.2-2 10 OREGON ADMINFSIRAHVF RULES
?.rnlv-pd for turbidity from each ronrce
whpre turbidity contaminat ion may be
prf"-"nt. Color and/op odor IpvpI* shall be
fl^rpr-nincl nonthiy when either the color
ppfl/c* odor i? suspected or known to excrrd
of the limits. If th" water quality is
variable, the sample shall he collected at
the tnc of surnected lowest oualitv.
(f) In thp event th?t analysis indicate?
that any physical duality limit ha? been
exce^d^d, the carrplinct and analysis shall
be reoeated promptly. The results of the
two measurements shall be averaged, and
recor«»>d.
(p;) The Division mav reouire that addi-
tional chyieal oi'ality sanplinr? and anal-
ysis b«» performed when jt Is known or sus-
pected that substandard water quality has
occurred in the distribution syrtem. (Vthen
any physical ouality contaminant is ex-
ceeded refer to subsection (8) below.)
CO Microbiological Quality:
(a) Maximum Contaminant Levels:
(A) When the membrane filter techr.ioue is
used (100 milliliter sample size), the
total coliform densities shall pot exceed
one per 100 milliliters as th*» arithmetic
mean of all samples examined opt month; and
cither:
(l) four oer 100 milliliters in more than
one standard sample when less than 20 are
examined per nonth; or
(nj four per 100 milliliters in more
than five percent of the standard sanples
when 20 or more are examined rer month.
(E) When the multiple tube frrmnrtation
nethod (10 milliliter standard portion?) is
used, total coliform organisms shall not be
present in more than 10 percent of the
portions in any month; and not be present
in either:
(I) three or more portions in more than
one sa^rle when less than 20 sampler are
examined ner month; or -
(II) three or more portions in more than
five percent of the samples if more samples
are exaTnpd per month.
138
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Appendix 5
CONSTRUCTION AND USE OF WASTE DISPOSAL WELLS - OREGON
ADMINISTRATIVE RULES 340-44-005 TO 340-44-045
"Construction or use of Waste Disposal Wells Prohibited
340-44-015 (1) After the effective date of these
regulations, no person shall construct or place in operation
any waste disposal well for the disposal of sewage without
first obtaining a permit for said construction or operation
of the waste disposal well frcm an approved permit-Issuing
agency.
(2) After the effective date of these regulations, no
person shall construct or place In operation any waste dis-
posal well for the disposal of sewage from a system serving
more than 25 families or 100 people or of wastes other than
sewage without first obtaining a permit from the State Sanitary
Authority [DBQJ.
(3) After January 1, 1975, no person shall maintain
or use any waste disposal well for the disposal of sewage
or wastes without a currently valid permit from an approved
permit issuing agency or the State Sanitary Authority [DEQ]
which specifically authorizes said maintenance or use.
It is the '.ntent of this sub-section to phase out, by
January 1, 1975, the use of waste disposal wells except
for those which are scheduled to be replaced by sewers in
aocordai.^e with an approvad plan and time-schedule, and those
which are operated under specific permit frcm the State
Sanitary Authority [DEQ] pursuant to section 340-44-045
of these regulations."
Statutory Authority:
Hist: Filed 5-15-69 as SA 41
"Waste Disposal Wells Prohibited Where Better Treatment or
Protections is Available
340-44-030 Permits shall not be issued for construction,
iraintenar.ee or use of waste disposal wells where any other
treatment or disposal method which affords better protection
of public health or water resources is reasonably available
or possible."
Statutory Authority:
Hist; Filed 5-15-69 as SA 41
139
-------
Appendix 5 con't.
"Abandonment and Plugging of Waste Disposal Wells
340-44-040 (1) A waste disposal well upon discontinuance
of use or abandonment shall iitmediately be rendered ccrtpletely
inoperable by plugging and sealing the hole to prevent the
well from being a channel allowing the vertical novenent of
water and a possible source of contamination of the ground
water supply."
"Construction or Use of tfeste Disposal Wells Prohibited
After January 1, 1980
340-44-045 After January 1, 1980, it shall be unlawful
for any person to construct, maintain or use waste disposal
wells for disposed of sewage or wastes unless said wastes
have been previously treated by methods approved by the
Sanitary Authority [DBQJ and further such treated wastes
shall be discharged to waste disposal wells only if specifically
approved and authorized by the Sanitary Authority [DEQ].
It is intended that this section will permit consideration
for approval by tha Sanitary Authority [DEQ] of waste
disposal to deep injection wells, constricted and operated
in accordance with a carefully engineer©] program, and for
disposal to waste disposal wells of adequately treated and
disinfected effluents frcm large, efficiently-operated,
municipal or county sewage treatment plants where continuous
and effective surveillance and control of waste treatment
and discharge can be assured so as to fully safeguard water
quality and the public health and welfare."
Statutory Authority:
Hist: Filed 5-15-69 as SA 41
140
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Appendix 6
WATER QUALITY STANDARDS AND MINIMUM DESIGN CRITERIA -
DESCHUTES RIVER BASIN - OREGON REVISED STATUTES
"Water Quality Standards Not to be Exceeded (to be adopted
pursuant to ORS 468.735 and enforceable pursuant to ORS
468.720, 468.990, a«3 468.992.)
340-41-565 (1) Notwithstanding the water quality
standards contained below, the highest and best practicable
treatment and/or control of wastes, activities, and flews
shall in every case be provided so as to maintain dissolved
oxygen and overall water quality at the highest possible
levels and water temperatures, coliform bacteria concentrations,
dissolved chemical substances, toxic materials., radioactivity,
turbidities, color, odor, and other deleterious factors at
the lowest possible levels.
(2) No wastes shall be discharged and no activities
shall be conducted which either alone or in combination with
other wastes or activities will cause violation of the following
standards in the waters of the Deschutes River Basin:"
1. Dissolved Oxygen: "DO concentrations shall not
be less than 90 percent of saturation at the seasonal idw,
or less than 95 percent of saturation in spawning areas during
spawning, incubation, hatching, and fry stages of salmonid
fishes."
2. Tenperature: "No measurable increases shall be
allowed when stream temperatues are 58°F or greater? or more
than 0.5°F. increase due to a single-source discharge when
receiving water terperatures are 57.5°F. or less or more
than 2°F. increase due to all sources ccnibined when stream
terperatures are 56°F. or less, except for specifically
limited duration activities which snay be specifically authorized
br, DEQ under such conditions as it my prescribe and which
are necessary to accomodate legitimate uses or activities where
temperatures in excess of this standard are unavoidable."
3. Turbidity: " (Jackson Turbidity Units, JIU): No
rors than 10 percent cumulative increase in natural stream
turbidities shall be allowed except for certain specifically
limited duration activities which may be specifically authorized
by DEQ under such conditions as it ray prescribe and which are
necessary to accomodate essential drudging, (sic), construetion,
or other legitimate uses or activities where turbidities in
excess of Luis standard are unavoidable."
4. pH: 6.5 - 8.5
141
-------
Appendix 6 jon't.
5. Coliform Eacteria: "Average concentrations of
coliform organisms shall not exceed 240 per 100 milliliters,
except during periods of high natural surface runoff."
"Bacterial pollution or otner conditions deleterious
to waters used for domestic purposes, livestock watering,
irrigation, battling, or shellfish propagation, or otherwise
injurious to public health shall not be allowed.
The liberation of dissolved gases, such as carbon-
dioxide, hydrogen sulfide, or other gases, in sufficient
quantities to cause objectionable odors or to le deleterious
to fish or other aquatic life, navigation, recreation, or
other reasonable uses made of such raters shall not be allowed.
The development of fungi or other growths having a
deleterious effect on stream bottoms, fish or other aquatic
life, or which are injurious to health, recreation, or industry
shall not be allowed.
The creation of tastes or odors or toxic or other
conditions t±at are deleterious to fish or other aquatic life
or affect the potability of drinldng water or the palatability
of fish or shellfish shall not be allowed.
The formation of appreciable bottom or sludge deposits
or the formation of any organic or inorganic deposits
deleterious to fish or other aquatic life or injurious to
public health, recreation or industry shall not be allowed.
Objectionable discoloration, scum, oily sleek or
floating solids, or coating of aquatic life with oil films
shall not be allowed.
Aesthetic conditions offensive to the human senses of
sight, taste, smell, or touch shall not be allowed.
Radioisotope concentrations shall not exceed Maximum
Permissible Concentrations (MPC's) in drinking water, edible
fishes or shellfishes, wildlife, irrigated crops, livestock
and dairy products, or pose an external radiation hazard.
The concentration of total dissolved gas relative to
atmospheric pressure at the point of sa.-rple collection shall
not exceed one hundred and five percent (105%) of saturation,
except when stream flew exceeds the 10-year, 7-day average
flood.
Dissolved Chemical Substances: Guide concentrations
listed below shall not be exceeded unless otherwise specifically
authorized by DEQ upon such conditions as it may deen
necessary to carry out die general intent of this plan and
to protect the beneficial uses set forth in section 340-41-562:
mg/1
Arsenic (As) 0.01
Barium (Da) 1.0
Boron (Bo).". 0.5
Cadmium (Cd) 0.003
Chrcmium (Cr) 0.02
Copper (Cu) 0.005
142
-------
Apperdix 6 con't.
Cyanide (Cn)..........
Fluoride (F)
Iron (Fe)
Lead (Pb)
Manganese (Mn)
Phenols (totals)
Total dissolved solids
Zinc (Zn)
0.005
..1.0
..0.1
.0.05
.0.05
0.001
500.0
.0.01"
Minimum Design Criteria for Treatment and Control of Wastes
(340-41-575 in part)
"During periods of low stream flows (approximately
April 1 to October 31): Treatment resulting in monthly average
effluent concentrations not to exceed 10 mg/1 of BCD and 10
mg/1 of SS or equivalent control.
During the period of high stream flows (approximately
November 1 to March 31): A minimum of secondary treatment
or equivalent and unless otherwise specifically authorized
by the Department, operation of all waste treatment and control
facilities at majumum practicable efficiency and effectiveness
so as to minimize waste discharges to public waters.
Effluent BOD concentrations in mg/1, divided by the*
dilution factor (ratio of receiving stream flew to effluent
flows) shall riot exceed one (1) unless otherwise approved by
the BQC.
Sewage wastes shall be disinfected, after 'treatment,
equivalent to thorough mixing with sufficient chlorine to
provide a residual of at least 1 part per million after '60
minutes of contact time unless otherwise specifically authorized
by permit.
Positive protection shall be provided to prevent by-
passing raw or inadequately treated sewage to public waters
unless otherwise approved by the Department where elimination
of inflow and infiltration trould be, necessary but not
presently practicable.
More stringent waste treatment and control require-
ments may >_a imposed where special conditions may require."
143
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Appendix 7
Department of Environmental Quality
522 SOUTHWEST 5TH AVE PORTLAND OPEGC.N
MAILING ACDRESS P 0 BOX >760 PORTLAND CREGOM 37;07
March li», 1973
North Unit Irrigation District
Route 2, Box 1224
Madras, OR 377^1
Attention: Mr. Roscr S. Norland, Secretary-Manager
Re; NPDES Permit Pevocation
Gentlemen:
As you nra probably aware, the Clean Water Act of 1577 rcade several
significant changes In the Federal Water Pollution Control Act. One of
the changes made was to remove Irrigation return flew frcn the point
source category and Identify it as a non-point source. This means that
a»* UPDES permit Is no longer required for Irrigation return flows.
Sln^e your NP0E5 permit ?!o. I672J Is no longer legally required, 1
hereby revoke It. If you object to this rovccatlon please notify :re
within 20 days.
Since Irrigation return flows are to be controlled by best rranngement
practices In accordance with a statewide managenant plan (203) I trust
you win continue to be envlronrcsntally conscious and do all you can to
holp tha 208 planning process develop a workable plan. If you have any
questions about progress being made In that area please contact Mr. Pell
Hullane of this office at 22S-6065.
Thank you for your cooperation.
Sincerely,
WILLIAM H. YOUNG
D1rector
CKA:aes
144
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Appendix 8
Department of Environmental Quality
CENTRAL REGION
2150 N E STUDIO ROAD, BEND. OREGON 97701 PHONE (503) 382-6446
February 8, 1979
Bend Engineer ing Consultants
Bend, OR 97701
S - Bend Phase I
Deschutes County
Attn: Mr. Pat Case
Gentlemen:
For discharge to the North Unit Irrigation District Canal or to a
disposal well, the Department believes the new City of Bend sewage
treatment plant should, on an interim basis, treat to a 20-20 level,
i.e. 20 mg/1 BOD-5 and 20 mg/1 total suspended solids. The plant
should be designed for ultimate addition of necessary equipment to
treat to a 10-10 level. Disinfection shall be provided to achieve
a fecal coliform level less than 10 per 100 ir.ls.
We believe these treatment standards will adequately protect the
beneficial uses of either receiving body.
Should the city desire to discharge to the irrigation canal, written
permission must be granted by the irrigation district. Dischaige to
a disposal well must be in accordance with the provisions of
OAR 340-44-045.
Hopefully, this answers your questions.
Sincerely
Richard J. Nichols
Regional Manager
RJN:dmc
cc:City of Bend
:Water Quality Division
14€»
-------
Appendix 9
CURRENT WATER POLLUTION CONTROL FACILITIES PERMIT -
CITY OF BEND
146
-------
DEPARTMENT OF ENVIRONMENTAL I....L1TY
1234 S. 'V. Morrison Street
Portlard, Oregon 97205
Telephjne: (503) 229-5696
P»._«iit Number: 2610
Expiration Date: 6-30-02
Pile Number: 7517
Page 1 of 7
WATER POLLUTION CONTROL FACILITIES PERMIT
Issued pursuant to ORS 468.740
ISSUED TO:
SOURCES COVERED BY THIS PERMIT:
City of Bend
P. O. Box 431
Type of Waste Method of
Disposal
Bend, Oregon 97701
Domestic Lava sink
land
hole and
PLANT TYPE AND LOCATION:
Activated sludge
RIVER BASIN INFORMATION
East of Pilot Butte
Major Basin: Deschutes
Minor Basin:
County: Deschutes
Issued in response to application number
2158 received
3-10-77 .
Nearest surface stream which
could be influenced by waste
AUG i 0 1377
disposal system: Deschutes River
billiqim K. Jf/Ung
Director v
Date
PERMITTED ACTIVITIES
Until this permit expires or is modified or revoked, the permittee is authorized
to construct, install, modify or operate waste water treatment, control and dis-
posal facilities in conformance with requirements, limitations and conditions
set forth in attached schedules as follows:
Page
Schedule A - Waste Disposal Limitations 2_
Schedule B - Minimum Monitoring and Reporting Requirements 3_
Schedule C - Compliance Conditions and Schedules 4_
Schedule D - Special Conditions 5
General Conditions 6-7
All direct discharges to public waters are prohibited.
This permit does not relieve the permittee from responsibility for compliance
with other applicable Federal, state or local laws, rules or standards.
147
-------
State of Oregon
Department of Environmental Quality
PERMIT CONDITIONS
Permit Number; 2610
Expiration Date: 6-30-82
Page 2 of 7
City of Bond
SCHEDULE A
Waste Disposal Limitations
1. No discharge to state waters.is permitted. All waste waters shall be
discharged to the sink hole or distributed on land for dissipation by
evapo-transpiration and controlled seepage by following sound irrigation
practices so as to prevent:
a. Prolonged ponding of waste on the ground surface;
b. Surface runoff or subsurface drainage through drainage tile;
c. The creation of odors, fly and mosquito breeding and other nuisance
conditions; and
d. The overloading of land with nutrients or organics.
2. The permittee shall, during all times of disposal, provide personnel
whose primary responsibilities are to assure the continuous performance
of the disposal system within the limitations of this permit.
3. Prior to disposal of the waste water it shall receive at least the following
treatment:
a. Monthly average effluent flow shall not exceed 3785 m^/d {1.0 MGD).
b. BOD and TSS shall not exceed a monthly average of 20 mg/1 or 76 kg/day
(166.8 lb/day); weekly average of 30 mg/1 or 113 kg/day (250 lb/day);
and a daily maximum of 170 kg (375 lb).
c. Effluent discharged to the sink hole shall receive disinfection
sufficient to reduce fecal coliform bacteria to a monthly average
of 200 per 100-ml or a weekly aveiaqe of no more than 400 per 100 ml.
d. Effluent disposed of on land shall receive disinfection sufficient to
reduce fecal coliform bacteria to a monthly average of no more than
20 per 100 ml. In no case shall the chlorine residual be permitted
to drop below 1.0 mg/1.
e. The effluent pH shall be within the range 6.0 - 9.0.
4. Unless approved otherwise in writing by the Department, a deep-rooted,
permanent grass cover shall be maintained on the land disposal area at
all times and periodically cut to maintain it in the growth cycle to insure
maximum iniiltration and evapo-transpiration rate during the disposar
season.
148
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State Of v,. egon remit Humbert 2610
Department of Environmental Quality Eapiration Date: 6-30-82
PERMIT CONDITIONS PaS® _JL_ of —2—
City of Ber.d
SCHEDULE B
Minimum Monitoring and Reporting Requirements
The permittee shall monitor the operation and efficiency of all treatment and
disposal facilities. Unless otherwise agreed to in writing by the Department
of Environmental Quality, data collected at.J submitted shall include but not
necessarily be limited to the following parameters and miniaua frequencies:
Item or Parameter
Minimum Frequency-
Type of Sample
Total Flow
Pounds Chlorine Used
Chlorine Residual (effluent)
BOD (influent G effluent)
Suspended Solids
(influent & effluent)
pH (influent & effluent)
Sludge Settleability Test
Fecal Colifonu
Daily
Daily
Daily
2 per week
per week
per week
per week
Quarterly
Monthly when irrigating
Grab
Composite
Composite
Grab
Grab
Grab
I
Monthly reports shall also include a record of the location ar)d method of
disposal of all sludge and a record of all equipment breakdowns and bypassing.
Reporting Procedures
Monitoring results shall be reported on approved forms. The reporting period is
the calendar month Reports must be submitted to the Department- by the 15th
day of the following month.
149
-------
State of Oregon
Department of Environmental Quality
PERMIT CONDITIONS
Permit Number: 2610
Expiration Date: 6-30-8?
Page 4 of 7
City of Bend
SCHEDULE C
Compliance Conditions and Schedules
1. As soon as practicable, but not later than January 1, 1980, the permittee
shall construct and place into operation sewage collection, treatment and
disposal facilities adequate to serve the unsewered portions of the City.
The permittee shall require all users of disposal wells in the City to
abandon their wells in accordance with OAS 340-44-040 and connect to
the Betid collection system.
2. It is the intent of Condition 1 above to help eliminate the use of sewage
disposal wells in the Bend area. Disposal of waste treatment products
Xrom any new facility shall be dcm« such that potential fcr contamination
of ground or surface waters shall be minimized.
Sewage treatment plant effluent disposal practices will be such that
discharge of effluent to disposal wells shall be done only on an emergency
basis and with specific approval fron the Department of Environmental Quality.
150
-------
State of Oregon
Department of Environmental Quality
PERMIT CONDITIONS
Permit Numbers
Expiration Date:
Page 5 of 7
6-30-02
2610
City of Bend
SCHEDULE D
Special Conditions
1. Prior to constructing or modifying any waste water control facilities,
detailed plans and specifications shall be approved in writing by the
Department.
2. An adequate contingency plan for prevention and handling of spills and
unplanned discharges shall be in force at all times. A continuing program
of employee orientation and education shall be maintained to ensure aware-
ness of the necessity of good inplant control and quick and proper action
in the event of a spill or accident.
151
-------
State Of l jgon .jrmit Number: 2610
Department of environmental Quality Expiration Date: 6-30-82
PERMIT CONDITIONS Pa9e —— o£ -2—
City of Bend
GENERAL CONDITION'S
Gl. The permittee shall provide an adequate operating staff which is duly
qualified to carry out the operation, maintenance and testing functions
required to insure compliance with the conditions of this permit.
G2. All waste collection, control, treatment and disposal facilities shall
be operated m a manner consistent with the following:
a. At all times all facilities shall be operated as efficiently as
possible and in a manner which will prevent discharges, health
hazards and nuisance conditions.
b- All screenings, grit and sludge shall be disposed of in a manner
approved by the Department of Environmental Quality such that it
does not reach any of the waters of the state or create a health
hazard or nuisance condition.
c. Bypassing of untreated was^e is generally prohibited. No bypassing
shall occur without prior written permission from the Department
except where unavoidable to prevent loss of life or severe property
damage.
G3. Whenever a facility expansion, production increase or process modifica-
tion is anticipated which will result in a change in the character of
pollutants to be discharged or which will result in a discharge to public
waters, a new application must be submitted together with the necessary
reports, plans and specifications for the proposed changes. No change
shall be made until plans have been approved and a new permit or permit
modification has been issued.
G4. After notice and opportunity for a hearing this permit may be modified,
suspended or revoked in whole or in part during its term for cause
including but not limited to the following:
a. Violation of any terms or conditions of this permit pr any appli-
cable rule, standard, or-order the Commission;
F
b. Obtaining this permit by misrepresentation or failure to disclose
fully all relevant facts.
G5. The permittee shall, at all reasonable tines, allow authorized represen-
tatives of the Department of Environmental Quality:
a. To enter upon the permittee's premises where a waste source or
disposal system is located or in which any records arc required
to be kept under the terms and conditions of this permit;
b. To ha\ e access to aid ccj-v anv records requned to bs kept '_!¦?
terms and conditions of thiii permit;
c. To inspect ar.y monitoring eqjipment or monitoring method required by
this permit; or
152
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State of *..egon
Department of Environmental Quality
PERMIT CONDITIO MS
remit Number: 2610
Expiration Date: 6-30-B2
Pt»ge 7 of 7
City of Bend
d. To sample any discharge of pollutants.
G6. The permittee shall at all times maintain in good working order and operate
as efficiently as possible all treatment or control facilities or systems
installed or used by the permittee to achieve compliance with the terms
and conditions of this permit.
G7. The issuance of this permit docs not convey any property rights in either
real or personal property, or any exclusive privileges, nor does it autho-
rize any injury to private property or any invasion of personal rights,
nor any infringement of Federal, State or local laws or regulations.
G8. The Department of Environmental Quality, its officers, agents and employees,
shall not sustain any liability on account of the issuance of this permit
or on account of the construction or maintenance of facilities because Of
this permit.
G9. In the event the permittee is anable to comply with all of the conditions
of this perait because of a breakdown of equipment or facilities, an acci-
dent caused by human error or negligence, or any other cause such as an act
of nature, the permittee shall:
a. Immediately take action to stop, contain and clean up the unauthorized
discharges and correct tne problem.
b. Immediately notify the Department of Environmental Quality so that an
investigation can be made to caluate the impact and the corrective
actions taken and determine additional action that must be taken.
c. Submit a detailed written report describing the breakdown, the actual
quantity and quality of resulting waste discharges, corrective action
taken, steps taken to prevent a recurrence and any other pertinent
information.
Compliance w\th these requirements does not relieve the permittee from
responsibility to maintain continuous compliance with the conditions of
this permit oi the resulting liability for failure to comply.
G10. Definitions of terms and abbreviations used in this permit:
a. BOD means five-day biochemical oxygen demand.
b. TSS moans total sur,tended solids.
c. mg/1 means milligrams per liter.
d. kg means kilograms.
e. -n3/d means cubic meters ^er day.
f. f'GD moans million gallons per day.
g. Averages for BOD and TSS are based on antlinetic mean of samples
taken.
h. Average CQliform or fecal coliform is based on geometric mean of
saiiples taken.
i. Composite sample means a combination'of samples col]ected, generally
it equal intervals over a 24-hour period, and apportioned accoidir.g
to thu voliime of flow dt the time of sampling.
2 . l'C moans fecal colvforin bacteria.
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