# APPENDIXT

UseAttainabilityAnalysis CaseStudies

WATER

# QUALITYSTANDARDSHANDBOOK

SECONDEDITION

### CASESTUDIES

Introduction

TheWaterBodySurvey andAssessment Guidance for Conducting Use Attainability Analyses provides guidance onthe factors that maybe examined todetermine if anaquatic life protection useis attainable inagiven stream or river system. Theguidance proposed that States perform physical, chemical and biological evaluations in order to determine the existing and potential uses of awater body. The analyses suggested within this guidance represent thetype ofanalyses EPAbelieves are sufficient for States to justify changes in uses designated in a water quality standard and to show in Advanced Treatment Project Justifications that the usesareattainable. States are also encouraged to usealternative analyses aslong asthey are scientifically andtechnically supportable. Furthermore, the guidance also encourages the use of existing data to perform the physical, chemical andbiological evaluations andwheneverpossible States should consider grouping water bodies having similar physical and chemical characteristics totreat several water bodies orsegments asasingle unit. Using the framework provided by this guidance, studies were conducted to (1) test the applicability of the guidance, (2) familiarize State andRegional personnel with the procedures and (3) identify situations whereadditional guidance is needed. Theresults ofthese casestudies, which are summarized inthis Handbook, pointed outthefollowing: (1) TheWaterBodySurveys andAssessment guidance canbeapplied and provides a good framework for conducting use attainability analyses; (2) Theguidance provides sufficient flexibility to the States in conducting suchanalyses; and, (3) Thecasestudies showthat EPAandStates cancooperatively agree to the data and analyses needed to evaluate the existing and potential uses. Uponcompletion ofthecasestudies, several States requested that EPAprovide additional technical guidance onthe techniques mentioned intheguidance document. Inorder tofulfill these requests, EPAhas developed a technical support manual on conducting attainability analyses andiscontinuing research todevelop newcost effective tools for conducting suchanalyses. EPAisstriving todevelop apartnership with States to improve the scientific andtechnical basesofthewater quality standards decision-making process andwill continue to provide technical assistance. The summaries of the case studies provided In this handbook illustrate the different methods States used in determining the existing andpotential uses. Ascanbeseen, the specific analyses usedwere dictated by (1) the characteristics of the site, (2) the D-1States capabilities andtechnical expertise using certain methods and

(3) the availability of data. EPAis providing these summaries to show how use attainability analyses can be conducted. States will find these case studies informative on the technical aspects of use attainability analyses andwill provide them with alternate views on howsuch analyses maybeconducted.

D-2WATERBO@YSURVEYANDASSESSMENT Assabet River, Massachusetts

A. Site Description
Thedrainage basin ofthe Assabet River comprises 175square miles 1ocated in twenty towns in East-Central Massachusetts. The Assabet River heqins as the outflow from a small wildlife preservation impollndrTent in the Town of Westborough and flows northeast through the urban centers of Northborough, Hudson, Maynard and Concord to its confluence with the Sudhury River, forming the Concord River. Between these arbani7ed centers, the river is bordered by stretches of rural and undeveloped land. Similarly, the vast majority of the drainage basin is characterized by rural development. Figure 1 presents a schematic diaqram of the drainage basin.
The Assahet River provides the opportunity to study a repeating sequence of water quality degradation and recovery. Oneindustrial and six dnmestic wastewater treatment plants (WWTP) discharge their effluents into this 31-mile long river. All of the treatment plants presently provide secondary or advanced secondary treatment, although manyof them are not performing to their design specifications. Most of the treatment plants are scheduTed to be upgraded in the near future.Interspersed among the WWTPdischarges are six low dams, all but one of which were huil t at least a half century ago. All are "run-of-the-river" structures varying in height from three to eleven feet. The last danl built on the river was a flood control structure completed in 19HO.
The headwaters of the Assahet River are formed by the discharge fro17 awildlife preservation impoundment, and are relatively "clean" except for low dissolved oxygen (DO)andhigh biochemical oxygen demand (ROD) during winter and summer. Water is discharged from the preserve throuqh the foot of the damthat forms the impoundment, andtherefore, tends to he low in IJO. 90 and RODproblems in the impoundment are attributed to winter ice cover and peakalgal growth in summer. After the discharqe of effluents from the Westborough and Shrewsbury mtJfliCipal wastewater treatment plants, the river enters its first deyradation/recovery cycle. The cycle is repeated as the river receives effluent from the four remaining domestic treatment plants. Water quality problems in the river are magnified when the effluents are discharcjed into the head of an impoundment. However, the flow of water over the damsalso serves asaprimary means of reaeration in the river, and thus, the damsalso hecomeamajor factor in the recovery seqmertt of the cyc;e. Water quality surveys performed in 1979 showed violation<, of the fecal coliform, phosphorus, and dissolved oxygen criteria throt,clholit the river.

D-3\I i I I i

- --. ‘\\ - m-4 -.

, * I ’ t IL I--- \

n-4At present, the entire length of the Assabet River is classified R, which is designated for the protection and propagation of fish, other aquatic life and wildlife, and for primary and secondary recreation. Twodifferent uses have been designated for the Assabet River--from river mile 31.8 to 12.4 the designated use is "aquatic life" andfrom river mile 12.4to the confluence with the Sudbury River the designated use is a"warmwater fishery". Thedifference in these designated uses is that maintenance of awarmwater fishery has a maximumtemperature criterion of 83degrees F, and aminimum 00of 5 mg/l. There are notemperature or DOcriteria associated with the aquatic life use. These designations seemcontrary to the existing data, which document violations of both criteria in the lower reaches of the river where warmwater fishery is the designated use.
0. Problem Definition
The Assabet River wasmanaged as a put and take trout fishery prior tothe early 1970swhenthe practice wasstopped onadvisement of the MllWPCbecause of poorwater quality conditions in the river. While the majority of the water quality problems are attributable to the wastewater treatment plant discharges, the naturally low velocities in the river, compounded byits impoundment in several places, led to the examination of both factors as contributors to the impairment of aquatic life uses. This combination of irreversible physical factors and wastewater treatment plant-induced water quality problems led to the selection ofthe Assahet River for this water bodysurvey. 

## c 1. Approach toUseAttainability Analysis
Assessment of the Assabet River is based on the previously mentioned site visits and discussions among representatives of the Massachusetts Division of Water Pollution Control (MDWPC);the l1.S. Environmental Protection Agency (EPA); and the Massachusetts Fish and Wildlife Division. This assessment is also based in part uponfindings reported in the field and laboratory analyses onthe Assahet River in early June, 1979, andagain in early August, 1979. These surveys are part of the on-going MDWPC monitoring program, which included similar water quality assessments of the Assabet in 1969and 1974. Thewater quality monitoring includes extensive information on the chemical characteristics ofthe Assahet River. Analyses Conducted
A review of physical, chemical and biological information was conducted to determine which aquatic life use designations would be appropriate.
A. Physical Factors
The lowflow condition of the river during the sumer months may have an impact on the ability of certain fish species to survive. Various percentages of average annual r;ow (AAF) have been used to describe stream regimens for critical fisheries flow. As reported in

o-5rl)rt pl 1 /19!?), stlJdies conducted by Tennant indicate that lo",, 30X, and 6n? nf &lF describe the range of fisheries flows from absolute 1'1 jni77"~I'lqw AAF) to optimum (604 of AAF). The average annual flow of the ?,5s45Pt >iver, as calculated from 39years of record at the USGS ,];11']" 1: r-i/or r:lile 7.7, is 183 cfs. Flow measurements taken at the 1171;\']"'ll]C~ orl four consecutive days in early August, 1979, were 43, 34, "7, Anti 3? cfs. These flows average about 19 percent of the AAF l~dicatil<~ that some impairment of the protection of fish species may occ11 r d11rto low flow in the river. The 7-day lo-year low flow for this r,ahch of the river is approximately 18to 20cfs.
The outstanding physical features of the Assabet River are the I111 I.;s, dhlch have a significant influence on the aquatic life of the -i ir'r-. Ml)St fish are incapable of migrating upstream of the dams, thus '1. itint; ttlrlir ahility to find suitable (sufficient) habitats when ;ri+lr,jl dq?tlr quality conditions occur. The low flow conditions !f)wv5+r‘),j'e ()f the riar~s dlJrinq dry periods also result in high water

l 4’;ltJ~,jt N,r-tJS, further limitinq fish survival in the river.

:<

. i:~ol,~~;ical Factors 

## *swith hlh&?' data on the physical parameters for the Assabet River,

data are sparse. The last fish survey of the Assabet River d?\ cl)pr!lctP(i bv the Massachusetts Fish and Wildlife Division in 1952. '("1')~ :)rrch, hlueqills, pickerel, sunfish, and hass were all observed. 7my."4 5

# j L+ '1Pt 7iver was sampled by the MDWPCfor macroinvertebrates at ‘,‘,,> !~:-3:ions in Ilbnp, 1979, as part of an intensive water quality :,“ii'i - Thrl ,!<ita ;qf!re rpvieweri and analvses performed to determine whether :ondi tionq precll~fie macroinvertebrate hahitats. The results were iI.'-oncl 11sive. 

## r. fhp-1 cd1Factors
Ilf all the chemical constituents measured in the June and August, 1II'0
, ddYt>r quality surveys, dissolved oxygen, ammonia nitrogen, and tof-II9r3tI,rfy have the greatest potential to limit the survival of dcj~~h+ ic life. Ammonia toxicity was investigated using the criteria 0i+l~rj~,j in Water Ouality Criteria 1972. The results of this analysis

---__ 1':'"+e that the concentration of un-ionized ammonia would need to be 7"f-,>d<,>A .ii,;Iroxir?ately three times before acute mortality in the c,:‘f',-707 >f fish listed would occur. Therefore, ammonia is not a :‘,r‘)hl,>"T#

Tc~~.l~er-dtures in the lower reaches of the Assabet frequently exceed +"(1-‘,?<,~ll,,V]temperature criteria (83 deqrees F) for maintenance of a da“'- writer fishery. However, temperature readings were taken in early ,311 1 13:~ a'tt-'rnoon and are believed to be surface water measurements. 'he,; jrrJ short-term localized ohservations and should not preclude the r.>~jif!*r~?prtl of awarmwater fishery in those reaches. nissolved oxygen

r>,- t, r- l r-3tlclns above Maynard are unsuitable for supporting cold or warm fi!*..r c?\n~rips, but are sufficient to support a fishery below this :',1-t.

D-6Theimpoundments mayexhibit water quality problems in the formof high surface temperatures andlowbottom DO. Surface temperatures have been found to besimilar to those in the remainder of the river. The only depth sample wasat 13feet in the wildlife impoundment, where the temperature was63degrees F,while 83degrees Fat the surface. While such bottom temperatures are likely to besufficient to support acold water fishery, it is likely that the DOat the bottom of the impoundments will be near zero due to benthic demands and lack of surface aeration, which would preclude the survival of anyfish, Findings
Thedata, observations, andanalyses aspresented herein lead to the conclusion that there are four possible uses for the Assabet: aquatic life, warmwater fishery, cold water fishery, andseasonal cold water fishery. The seasonal fishery would bemanaged bystocking the river during the spring.
These uses were analyzed under three water quality conditions: existing, existing without the wastewater discharges, and inclusion of the wastewater effluent discharges with treatment at the levels stipulated in the 1981Suasco Basin WaterOuality Management Plan. The no discharge condition is included as abaseline that represents the quality under "natural" conditions. 

### A. Existing Uses
Alimited number of warmwater fish species predominate in the Assabet River under existing conditions. The species should not be different from those observed during the 1952survey. Thecombination of numerous low-level damsandwastewater treatment plants with low flow conditions in the summer results in dissolved oxygen concentrations and temperatures which place severe stress on the metabolism ofthe fish.
Theobserved temperatures aremost conducive to support the growth of coarse fish, including pike, perch, walleye, smallmouth and largemouth bass, sauger, bluegill andcrappie.
The minimum observed DOconcentrations are unacceptable for the protection of anyfish. Water Quality Criteria establishes the values 6.8, 5.6, and 4.2 mg/l of 00 for high, moderate, and low levels of protection of fish for rivers with the temperature characteristics of the Assabet. The Draft National Criteria for Dissolved Oxygen in Freshwater establishes criteria as3.0 mg/l for survival, 4.0 mg/l for moderate production impairment, 5.0 mg/l for slight impairment, and6.0 for noproduction impairment. Theupper reaches will not even support awarmwater fishery at the survival level, except in the uppermost reach. Onthe other hand, the lower reaches can support awarmwater fishery under existing conditions.

D-7B. Potential Uses
The potential aquatic life uses of the Assabet River would be restricted bytemperature and low flow, andbyphysical barriers that would exist even if water quality (measured In terms of DOand bacteria) Is significantly improved. Despite anoverall improvement in treated effluent quality, the river would besuitable for aquatic life, asit is currently, andwould continue to betoo warmto support acold water fishery In the sumnertime. Theposslbillty of maintaining the cold water species in tributaries during the sutmnerwasinvestigated, but there are no data onwhich to draw conclusions. Water quality observations In the only tributary indicate temperatures similar to those in the mainstem. Therefore, the maintenance of a cold water fishery in the Assabet is considered unfeasible.
Theattainable uses in the river without discharges orat planned levels of treatment are warmwater fishery and seasonal cold water fishery. These uses are both attainable throughout the basin, but may be impaired in Reach 1, asthe water naturally entering Reach 1from the wildlife preservation impoundment is low in DO. Theseasonal cold water fishery is attainable because the discharge limits are established to maintain aDOof 5mg/l under 7010conditions. If the DOis 5mg/l under summerlow flow conditions, it will certainly be6 mg/l or greater during the colder, higher flow spring stocking period, andaseasonal cold water fishery would beattainable. According to the Fish andWlldlife Division, the impoundments of the Assabet River have the potential to be a valuable warm water fishery. The reaches of the river that have anon-vegetated gravel bottom also have a high potential to support a significant fishery because these habltats allow the benthic invertebrates that comprise the food supply for the fish to flourish. It wasfurther suggested that if the dissolved oxygen concentration could bemaintained above 5 mg/l, the river could again bestocked asaput andtake trout fishery In the spring. SumnaryandConclusions
The low flow conditions of the Assabet River have been exacerbated by the low damswhich span its course. In the summer months, the flow in the river is slowed asthe river passes through its Impoundments and flow below the damsis often reduced to a relative trickle. Whenflow is reduced, temperatures in the shallow river (easily walkable In manyplaces) can exceed the maximum temperature crlterlon for protection and propagation of a warm water fishery. Additionally, the damslimit the mobility offish. Atpresent, most of the river reaches also undergo extensive degradation due to the discharge of wastewater treatment plant effluent which is manifest in low dlssolved oxygen concentrations. All of these factors impair the aquatic life potential ofthe Assabet River.

D-8Three use levels corresponding with three alternative actions related to the wastewater discharges are possible in the Assabet. The no action alternative would result in very low dissolved oxygen concentrations in manyreaches which are appropriate only for the use designation of aquatic life andwarmwater fishery. In this scenario, fish would only survive in the lowest river reaches, andaquatic life would belimited to sludge wormsandsimilar invertebrates in the upper reaches. The remaining two alternatives are related to upgrading treatment plants in the basin. If the discharges are improved sufficiently to raise the' instream DOto 5 mg/l throughout, as stipulated in the 1981 Water Quality Management Plan, it will be suitable asawarmwater or seasonal cold water fishery. Should the discharge beeliminted altogether, the sameuseswould beattainable.
The treatment plant discharges inhibit the protection and propagation of aquatic life. Most of the treatment plants are scheduled to beupgraded in the near future, which would relieve the existing dissolved oxygen problems. Even if the river is returned to relatively pristine conditions, the type of fish that would beable to propagate there would not change, due to the existing physical conditions. However, the extent of their distribution, their abundance, andthe health ofthe biota would belikely to increase.
The present use designations of the Assabet River are sufficient to characterize the aquatic life useit is capable of supporting, while physical barriers prevent the year-round attainment of a "higher" aquatic life use. The potential aquatic life uses could include extension of the warm water and seasonal cold water fishery classifications to the entire length of the river, should the planned improvements to the wastewater treatment plants beimplemented.

D-9WATERBODYSURVEYANDASSESSMENT Blackwater River Franklin, Virginia

I. INTRODUCTION
A. Site Description
The area of the Blackwater River which waschosen for this study extends from Joyner's Bridge (Southampton County, Route 611) to Cobb's Uharf near its confluence with the Nottoway River (Table 1andFigure 1). ln addition, data from the USGSgaging station near Burdette (river mile 24.57) provided information onsomephysical characteristics ofthe system.

TABLE1 Sampling Locations for Blackwater River UseAttainability Survey
Station No. Location River Mile

: 3 Vicinity Joyner's Bridge, Route 611 20.90

Below Franklin SewageTreatment Plant Discharge 13.77 Vicinity Cobb's Wharf, Route 687 2.59

Themeanannual rainfall is 48inches, muchof which occurs in the sutwner in the form of thunderstorms. The SCShas concluded that approximately 41,000 tons of soil are transported to streams in the watershed due to rainfall induced erosion. Seventy (70) percent of this originates from croplands, causing apotential pllution problem from pesticides andfrom 4 fertilizer based nutrients. In adition, 114,000 pounds of animal waste are produced annually, constituting the only other major source of non-point pollution.
There are two primary point source discharges onthe Rlackwater River. The Franklin SewageTreatment Plant at Station 2discharges anaverage of 1.9 mgdofmunicipal effluent. Thedischarge volume exceeds NPDESpermit levels due to inflow and infiltration problems. The plant has applied for a federal grant to upgrade treatment. Thesecond discharge is from Union Camp Corporation, an integrated kraft mill that produces bleached paper and bleached board products. The primary by-products are crude tall oil and crude sulfate turpentine. Union Campoperates at 36.6 mgdbut retains its treated waste in lagoons until the winter months whenit is discharged. The

O-10Figure 1. MapofStudy Area Southampton Co., VA Scale 1:5000

Cobb's Wharf

Virginia
-- -- North Carolina

D-11Union Campdischarge point is downstream from Station 3just above the

North Carolina State line at river mile 0.70.
Thetopography surrounding the Blackwater River is essentially flat andthe riparian zone is primarily hardwood wetlands. There is agoodsurface water supply from several swamps. At the USGSgaging station near Burdette, Virginia, the discharge for calendar year 1980averaged 430cfs. TheBlackwater River from Joyner's Bridge (Station 1)to Franklin is classified bythe State Water Control Board (SWCB)asaClass III free flowing stream. This classification requires aminimum dissolved oxygen concentration of 4.0 mg/l andadaily average of 5.0 mg/l. Other applicable standards are maintenance of pHfrom 6.0 to 8.5 andamaximumtemperature of 32°C. The riparian zone is heavily wooded wetlands with numerous channel obstructions. Near Franklin the canopy begins to open andthere is anincreasing presence of lily padsandother macrophytes. Thewater is dark, as is characteristic oftannic acid water found'in swamplands.
Below Franklin the Blackwater River is dredged and channelized to permit barge traffic to reach Union Camp.The channel is approximately 40mwide andfrom5mto8min depth. This reach of stream is classified bythe SWCB asaClass II estuarine system requiring the samedissolved oxygen andpH limitation asinClass III but without atemperature requirement.
B. Problem Definition
The study area onthe Blackwater River includes aClass III free-flowing stream andaClass II estuarine river. Part of the Class III section is a freshwater cypress swamp. The water is turbid, nutrient enriched and slightly acidic dueto tannins.
In response to the EPArequest for Virginia's involvement in the pilot Use Attainability studies, the State Water Control Board chose to examine the Blackwater River in the vicinity of Franklin, Virginia. There were several reasons for this choice. First, the major stress to the system is lowdissolved oxygen (DO) concentrations which occur from Maythrough November. Surveys conducted bySWCBstaff, andofficials from Union Campin Franklin, found that during certain periods "natural" background concentrations of dissolved oxygen fell below the water quality standard of 4.0 mg/l. This has raised questions as to whether the current standard is appropriate. Virginia's water quality standards contain aswampwater designation which recognizes that DOand pHmay be substantially different in someswamp waters and provides for specific standards to be set on acase by case basis. However, nosite specific standards have beendeveloped in Virginia to date. Oneof the goals of this project wasto gather information which could lead to possible development of a site specific standard for the Blackwater River. Second, the Franklin STPhasapplied for afederal grant to provide for improved BODremovals from its effluent.

D-12C. Approach to UseAttainability

On20April, 1982, staff of the SWCBmet with several EPAofficials and their consultant. After visiting the study area onthe Blackwater River and reviewing the available information, it wasdetermined that further data should becollected, primarily adescription of the aquatic community. The SWCBstaff has scheduled four quarterly surveys from June 1982, through March 1983, to collect physical, chemical, andbiological information. Interim results are reported herein to summarize data from the first collection. Final conclusions will not bedrawn until the data hasbeencompiled for all four quarters.

II. ANALYSESCONDUCTED
A. Physical Analysis
Data onthe physical characteristics of the Blackwater River were derived primarily from existing information andfrom general observations. Theentire reach ofthe Blackwater River fromJoyner's Bridge toCobb's Wharfwas traveled by boat to observe channel and riparian characteristics. Asediment sample wascollected at each station for partical size analysis.
B. Chemical Analysis
Water samples were collected at Stations 1-3 for analysis of pH,alkalinity9solids, hardness, nutrients, five-day BOO, chemical oxygen demand, total organic carbon, phenols, pesticides, and heavy metals. In addition, previous data ondissolved oxygen concentrations collected bythe SWCBand Union Campwere used to examine oxygen profiles in the river. The USGS Water Resources Oata for Virginia (1981) provided somechemical data for the Blackwater River near Burdette. C. Biological Analysis Periphyton sampling for chlorophyll-a, biomass, and autotrophic index rietermination wasconducted using floating plexiglass samplers anchored bya cement weight. Thesamplers were placed in the field in triplicate and remained in the river for 14days. They were located in run areas in the stream. Atthe endofthis two-week period, the samplers were retrieved and the slides removed for biomass determinations andchlorophyll analysis.
Both acursory and aquantitative survey of macroinvertebrates were conducted at each station. The purpose of the cursory study wasto rapidly identify the general water quality of each station bysurveying the presence of aquatic insects, molluscs, crustaceans andworms and classifying them according to their pollution tolerance. A record was kept of all organisms found andthese were classified to the family level asdominant, abundant, conmon, few or present. Thecursory survey wascompleted with a qualitative evaluation of the density anddiversity of aquatic organisms.

D-13General knowledge of the pollution tolerance of various genera wasusedto

classify the water quality at each statlon. The benthic macroinvertebrate samples were collected with Hester-Dendy multiplate artiflclal substrates. The substrates were attached to metal fence posts and held vertically at least 15cmabove the stream bottom. Thesubstrates were left in place for six weeksto allow for colonization bymacroinvertebrate organisms. In the laboratory the organisms were identifled to the generic level whenever possible. Counts weremadeof the number of taxa identified andthe number of Individuals within eachtaxon. Fish populations were surveyed at eachstation byelectrofishing. Eachstation was shocked for 1,000 seconds: BOOseconds at the shoreline and200 seconds at midstream. Fish collected were identified to species and the total length of each fish was recorded. In addition, general observations were madeabout the health status of the fish byobserving lesions, hemorrhaging, andthe presence of external parasites. Diversity of species wascalculated using the Shannon-Weaver index. Additionally, the fish cormnunities were evaluated using an index proposed by Karr (1981) which classifies biotic integrity basedon12parameters ofthe fish community.

III. FINDINGS
There are few physical factors which limit aquatic life uses. Thehabitat is characteristic of ahardwood wetland with few alterations. The major alteration is dredging andchannelizatlon below Franklin which eliminates much of the macrophyte communfty and the habitat it provides for other organisms. Thesubstrate at eachstation wascomposedmostly of sandwith a high moisture content. This Is characteristic of aswampbut is not ideal habitat for colonization byperiphyton andmacroinvertebrates.
DOconcentrations are typIcally below the Virginia water quality standards during the months of Maythrough November. This is true upstream aswell as downstream from the Franklin STPandappears to occur evenwlthout the impact of BODloadings from Franklin. This phenomenon maybetypical of enriched freshwater wetlands. However, during the winter months, DOconcentrations mayexceed 10mg/l. Another survey conducted bySWCBshowed that there were only small changes in DOconcentration with depth. Representatives from 17families ofmacroinvertebrates wereobserved during acursory investigation. These included mayflies, scuds, midges, operculate and non-operculate snails, crayfish, flatworms, and afreshwater sponge. Themajority of these organisms were facultative at Stations 1and2. HOWever, there were afewpollution sensitive forms at Station 1, andStation 3wasdominated bypollution sensitive varieties.
Twelve (12) species from seven families of fish were observed during the June 1982 study. Several top predators were present including the bowfin,

D-14chain pickerel, largemouth bass and longnose gar. Other fish collected were

the American eel, shiners, pirate perch, yellow perch, andfive species of sunfish. Noneof the species are especially pollution sensitive. Results of the fish population survey are presented inTable 2.

TABLE2 Results of Fish Population Survey in Blackwater River, 9June 1982

Number No.of Diversity Proportion of Station Collected Species d Omnivores Carnivores

:: Joyner's Franklin Bridge

STP 19

51 7

6 2.30

5 .r)OO

OOO .157

098 3. Cobb's Wharf 44 6 2.35 .ooo .114

Based onthe EPA304(a) criteria, low seasonal 00concentrations measured in the river should present asignificant stress to the biotic community. Large fish tend to be less resistant to low DOyet large species such as the largemouth bass, American eel and somesunfishes were present in an apparently healthy condition. Theexplanation for this is unclear. The low dissolved oxygen concentrations are near the physiological limit for many species. Fish maybeable to acclimate to lowDOto alimited extent if the change in oxygen concentration occurs gradually. The fact that fish are present in ahealthy condition suggests that there is alack of other significant stressors in the system which might interact with lowDOstress. It is worth noting that spawning probably occurs in most species before the Sumnermonths whendissolved oxygen concentration becomecritically low.
Theautotrophic index determinations showthe Joyner's Bridge andFranklin STPstations ashaving relatively healthy periphyton communities. In each case over 80percent of the periphytic community wasautotrophic in nature. Basedonthe autotrophic index, both of these stations were in better biological health than the most downstream station, Cobb's Wharf. At Cobb's Wharf the autotrophic index characterized an autotrophic community which wasexperiencing aslight decline in biological integrity (74percent autotrophic ascompared togreater than 80percent upstream).
Chemical analyses conducted on water from the Blackwater River did not reveal any alarming concentration of toxicants whencompared to EPAWater Quality Criteria Documents, although the zinc concentration at Station 1 wasslightly above the 24-hour average recommended byEPA.Onesample collected by the USGShad azinc concentration which wastwice this number. Thesource ofthis zinc is unknown. Anyimpact which exists from this problem should be sublethal, affecting growth and reproduction of primarily

D-15the most sensitive species. The actual impact of zinc concentrations at

Joyner's Bridge is unknown. Analyses of the periphyton data aswell asthe water chemistry data indicate that the Blackwater River is nutrient enriched. Someof this nutrient load comesfrom inadequately protected crop lands andfrom domestic animal wastes. The Franklin STPalso contributes to higher nutrient concentrations. Additionally, anSWCBreport estimated that between river mile 20.0 and6.0, 1,600 lb per dayof non-point source carbonaceous ROD (ultimate) are added to the river. Consequently, these point and non-pant sources appear to becontributing to both organic enrichment and lower dissolved oxygen concentrations.

IV. SUMMARY

ANDCONCLUSIONS
TheBlackwater River from river mile 2.59 to 20.90 has been characterized asanutrient enriched coastal river muchofwhich is bordered byhardwood wetlands. Periphytic, macroinvertebrate, and fish cotmnunities are healthy with fair to goodabundance anddiversity. Themajor limitation to aquatic life appears to be low00concentrations which are enhanced by point and non-point sources of nutrients andBOO.Asecondary limitation maybeelevated zinc concentrations atJoyner's Bridge.
Theprimary difficulty in assessing the attainability of aquatic life uses is locating asuitable reference reach to serve asanexample of anunaffected aquatic community. Originally, Joyner's Bridge (Station 1) was selected for this purpose, but fewmajor differences occur between populations at all three stations. However, the widespread non-point pollution in Southeastern Virginia makesthe location of anundisturbed reference reach impossible, Theonly alternative, then, is to makethe best possible judgment as to what organisms might reasonably be expected to inhabit the Blackwater.
In reference to the Blackwater River, it is probable that mostfish species are present that should reasonably beexpected to inhabit the river, although possibly in lower numbers. (Noattempt hasyet beenmadeto assess this with regard to algal andinvertebrate communities.) However, based on the 304(a) criteria, the low DOconcentrations represent a significant stress of the ecosystem andthe introduction of additional stressors could bedestructive. It is also probable that higher oxygen concentrations during winter months play amajor role in reducing the impact of this stress. Removal of point and non-point source inputs mayalleviate someproblems. However, DOconcentrations maystill remain low. The increased effect of oxygen concentrations should beanincrease in fish abundance andincreased size of individuals. Diversity would probably beunaffected. Nevertheless, noattempt hasbeenmadeto estimate the magnitude of these changes.
Cairns (1977) hassuggested amethod for estimating the potential of abody ofwater to recover from pollutional stress. Although this analysis is only

D-16semi-quantitative and subjective, it suggests that the chances of rapid

recovery following adisturbance in the Blackwater River are poor. Theabsence of anundisturbed reference reach andthe dffffcu’lty in quaotifjfing changes in dissolved oxygen, population structure, and population abundance makeadefinite statement regarding attainability of aquatic life uses difficult. However, to surmnarize, several points stand out. First, the aquatic cotmnunities in the Blackwater River are generally healthy with fair to goodabundance anddistribution. Dissolved oxygen concentrations are low for about half of the year which causes asignificant stress to aquatic organisms. Oxygen concentrations are higher during the reproductive periods of manyfishes. Because of these stresses andthe physical characteristics of the river, the system does not havemuchresiliency orcapacity towithstand additional stress. Although aquantitative statement of changes in the aquatic cotnnunity with the amelioration of DOstress hasnot beenmade, it is probable that additional stresses would degrade the present aquatic community.
The occurrence of lowdissolved oxygen concentrations throughout much of the Blackwater is, in part, a"natural" phenomenon andcould argue for a reduction in the DOstandard. However, if this standard were reduced ona year round basis it is probable that the aquatic comnunity would steadily degrade. This mayresult in acontravention of the General Standard of Virginia State Lawwhich requires that all waters support the propagation andgrowth of all aquatic life which can reasonably beexpected to inhabit these waters. Because of the lack of resiliency in the system, ayear round standards change could irreversibly alter the aquatic community.

D-17WATERBODYSURVEYANDASSESSMENT Cuckels Brook Bridgewater Township, NewJersey

I. INTRODUCTION
A. Site Description
Cuckels Brook, asmall tributary of the Raritan River, is located entirely within Bridgewater Township in Somerset County, NewJersey. It is aperennial stream approximately four miles long, having awatershed area of approximately three square miles. Theentire brook is classified asFW-2Nontrout in current NewJersey Department of Environmental Protection (NJDEP) Surface Water Quality Standards.
Decades ago, the downstream section of Cuckels Brook (below the Raritan Valley Line Railroad, Figure 11, wasrelocated into anartificial channel. This channelized section of Cuckels Brook consists of anupstream subsection approximately 2,000 feet in length andadownstream subsection approximately 6,000 feet in length, with the Somerset-Raritan Valley Sewerage Authority (SRVSA) municipal discharge being the point of demarcation between the two. Thedownstream channelized subsection (hereinafter referred to as"Lower Cuckels Brook") is used primarily to convey wastewater to the Raritan River from SRVSAand the American Cyanamid Company, which discharges approximately 200feet downstream of SRVSA.Atits confluence with the Raritan River, flow in Lower Cuckels Brook is conveyed into Calco Dam, adispersion damwhich distributes the flow across the Raritan River. Except for railroari and pipeline rights-of-way, all the land along Lower Cuckels Brook is owned bythe American Cyanamid Company. Land use in the Cuckels Brook watershed above the SRVSAdischarge is primarily suburban but includes major highways.
B. Problem Definition
Lower Cuckels Brook receives two of the major discharges in the Raritan River Basin. SRVSAis a municipal secondary wastewater treatment plant which hadanaverage flow in 1982of 8.8 mgd(design capacity =10mgdl. TheAmerican Cyanamid wastewater discharge is amixture of process water from organic chemical manufacturing, cooling water, storm water, and sanitary wastes. This mixed waste receives secondary treatment followed by activated carbon treatment. In 1982 American Cyanamid's average flow was 7.0 mgd(design capacity 20mgd). Thesetwodischarges totally dominate the character ofLower Cuckels Brook. Over 90percent of the flow in Cuckels Brook is wastewater (except after heavy rainfall). Themeandepth is estimated to bebetween 1and2feet, andthe channel bottom at observed locations is covered with deposits of

D-18

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CUCKELS BROOK STUDYAREA wm4 ocTom!R 1982 s*uPLltm LOCATE

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D-19black sludge, apparently derived from solids in the SRVSAandCyanamid discharges (primarily the SRVSAdischarge). In contrast, the channelized subsection of Cuckels Brook above the SRVSAdischarge is often only inches deepwith abottom of bedrock, rubble, gravel andsilt. Cuckels Brook (including Lower Cuckels Brook) is classified as FW-2Nontrout in the NJDEPSurface Water Quality Standards. TheFW-2classification provides for the following uses: 1. Potable water supply after such treatment asshall berequired by lawor regulation;
2. Maintenance, migration, andpropagation of natural andestablished biota (not including trout);
3. Primary contact recreation;
4. Industrial andagricultural water supply; and
5. Anyother reasonable uses. The attainment of these uses is currently prevented by the strength and volume of wastewaters currently riischarged to Cuckels Brook. The size of the stream also limits primary contact recreation andother water uses, and physical barriers currently prevent the migration of fish between Cuckels Brook andthe Raritan River.
C. Approach to UseAttainability
In response to an inquiry from EPA, Criteria and Standards Division, the State of NewJersey offered to participate in ademonstration Water Body Survey andAssessment. Thewater bodysurvey of Cuckels Brook wasconducted bythe NewJersey Department of Environmental Protection, Bureau of Systems Analysis andWasteload Allocation; with assistance from the EPARegion II Edison Laboratory. Theassessment is based primarily onthe results of afield sampling program designed and conducted jointly by NJDEPand EPA-Edison in October 1982. Additional sources of information include self-monitoring reports furnished bythe dischargers, andearlier studies conducted bythe NJDEPon Cuckels Brook andthe Raritan River. Basedonthis assessment, NJDEPdeveloped a report entitled "Lower Cuckels 8rook Water Body Survey and Use Attainability Analysis, 1983.”
II. ANALYSESCONOUCTED
A. Chemical Analysis
Themajor impact ofthe SRVSAdischarge is attributed to un-ionized ammonia andTRClevels, whoseconcentrations at Station 4, 100feet below the discharge point were 0.173 and 1.8 mg/l respectively, which are 3.5 and600

D-20times higher than the State criteria. Theun-ionized ammoniaconcentration

of the Cyanamid effluent was low, but stream concentrations at Stations 6 and7were relatively high (though below the State criterion of 0.05 mg/l).
TheCyanamid discharge contained 0.8 mg/l TRC.Concentrations at both Stations 6and 7were 0.3 mg/l TRC, lower than at Station 4but still 100 times the State criterion of 0.003 mg/l. Theother major impact of the Cyanamid effluent wason instream filterable residue levels. Concentrations at Stations 6and7exceeded 1,100 rng/l, over three times the State criterion (133 percent of background). Theeffluents apparently buffered the pHof Lower Cuckels Brook which was approximately pH7at Stations 4, 6and 7, and the pti of the upstream reference stations wasmarkedly alkaline. Dissolved oxygen concentrations decreased in the downstream direction despite low0005 concentrations both in the effluents andinstream. This suggests anappreciable sediment oxygen demandin Lower Cuckels Brook. Dissolved oxygen levels were greater in the twoeffluents than in the stream at Stations 6and7. Thedissolved oxygen concentration at Station 7of 4.1 mg/l nearly violated the State criterion of 4.0 mg/l; this suggests the potential for unsatisfactory dissolved oxygenconditions during the Sumner.
The results of the water body survey are generally in good agreement with other available data sources. Recent self-monitoring data for both American Cyanamid andSRVSAagree well with the data collected in this survey. In particular they show consistantly high TRCconcentrations in both effluents. High average dissolved solids (filterable residue) concentrations are reported for the Cyanamid effluent. Total ammonia levels ashigh as33.5 mg/l NH3(27.6 mg/l N)were reported for the SRVSAeffluent. ThepHof the Cyanamid andSRVSAeffluents is sometimes morealkaline than the water body survey values indicating that toxic un-ionized amnonia concentrations may sometimes behigher than measured during the water bodysurvey. 8. Biological Analysis
Fish andmacroinvertebrate surveys were conducted in the channelized subsection ofCuckels Brook abovethe SRVSAdischarge. Only three fish species were found: the banded killifish, the creek chub andthe blacknose date. Onehundred andeighty-six (186) out of the total 194specimens collected were banded killifish. Killifish are very hardy andare commonin both estuarine andfreshwater systems. The largest fish found, acreek chub, was 146mmlong.
The results of the macroinvertebrate survey are discussed in detail in a separate report (NJDEP, 1982). Four replicate surber samples were collected at Stations 1and2above the SRVSAdischarge. Diversity indices indicate the presence of similar well-balanced communities at both stations. Species diversity andequitability were 3.9 and0.7 respectively at Station 1, and 4.3 and0.7 respectively at Station 2. Productivity at Stations 1and2was

D-21low, with meandensities of 59and89individuals per square foot, respectively. Themajority of species found at both stations have organic pollution tolerance classifications of tolerant (dominant at Station 1)or facultative (dominant at Station 2). Overall, the biological data indicate that the upstream channelized subsection of Cuckels Brook supports alimited fish cotmnunity andalimited macroinvertebrate community of generally tolerant species. Thewater quality data indicates nothing that would limit the conmiunity. Onepossible limiting factor is that, asaresult of channelization, the substrate consists of unconsolidated gravel andrubble onbedrock, which might easily bedisturbed byhigh flow conditions.
Both the chemical data andvisual observations at various locations suggest that virtually noaquatic life exists along Lower Cuckels Brook: not even algae were seen. Thedischarges have seriously degraded water quality. Unionized ammonia concentrations at Station 4were close to acute lethal levels, while concentrations of TRCwere above acute levels at Stations 4, 6and7(EPA, 1976). Thesludge deposits which apparently cover mostof the bottom of lower Cuckels Brook could exert negative physical (i.e. smothering) andchemical (i.e. possible toxics) effects onanybenthic organisms. Nobiological survey of the lower brook wasmadebecause of concern about potential hazards to sampling personnel. Supplemental sampling of the sediments is planned to ascertain levels oftoxics accumulation.
Aspart of their self-monitoring requirements, American Cyanamid performs weekly 96-hour modified flow-through bioassays with fathead minnows using unchlorinated effluent. Of63bioassays conducted between 1May, 1981and 31August, 1982, results from eight bioassays had 96-hour LC50values at concentrations of effluent less than 100percent (i.e. 26percent, 58percent, 77percent, 83.5 percent, 88percent, 92percent, and95.5 percent). These results suggest that the American Cyanamid effluent would not beextremely toxic if it were reasonably diluted byits receiving waters. Within Lower Cuckels Brook, however, the effluent receives only approximately 50 percent dilution andthe potential exists for toxic effects onanyaquatic life that maybepresent. These effects would bein addition to the toxicity anticipated from the TRCconcentrations which result from the chlorination of the effluent.
III. FINDINGS Practically noneof the currently designated uses are nowbeing achieved in Lower Cuckels Brook. Theprincipal current use of Lower Cuckels Brook is the conveyance of treated wastewater and upstream runoff to the Raritan River. Judging from the indirect evidence of chemical data andvisual observations, virtually noaquatic life is maintained or propagated in Lower Cuckels Brook. It has been well documented that fish avoid chlorinated waters (Cherry andCairns, 1982; Fava andTsai, 1976). Any aquatic life that does reside in Lower Cuckels Brook would besparse andstressed. Migration of aquatic life through Lower Cuckels Brook would probably only occur during periods of high storm water flow whensomeflow occurs over the

n-22un-named dam(Figure 1) which is designed to direct the flow of Cuckels

Brook toward Calco Dam.Calco Damand its associated structures, including the un-named dam, normally prevent the migration of fish between Cuckels Brook andthe Raritan River.
Lower Cuckels Brook currently does not support any primary or secondary contact recreation. Nowater is currently diverted from Lower Cuckels Brook for potable water supply, industrial or agricultural water supply, or any other purpose. Because Lower Cuckels Brook receives large volumes of wastewater and because there is practically no dilution, water quality in Lower Cuckels Brook has beendegraded to the quality of wastewater. Moreover, the bottom of Lower Cuckels Brook has been covered at observed locations with wastewater solids. Asaresult, Lower Cuckels Brook is currently unfit for aquatic life, recreation, andmost other water uses. Thetechnology-based effluent limits required bythe Clean Water Act are not adequate to protect the currently designated water uses in Lower Cuckels Brook. SRVSAalready provides secondary treatment (except for bypassed flows in wet weather), and American Cyanamid already provides advanced treatment with activated carbon. Because the Raritan River provides far more dilution than does Cuckels Brook, effluent limits which maybedeveloped to protect the Raritan River would not beadequate to protect the currently designated water uses in Lower Cuckels Brook. Theonly practical wayto restore water quality in Lower Cuckels Brook would beto remove the wastewater discharges. However, there are several factors that would limit the achievement of currently designated uses even if the wastewater discharges were completely separated from natural flow. If it were assumed that the wastewater discharges andsludge were absent, andthat the seepage of contaminated groundwater from the American Cyanamid property wasinsignificant or absent, then the following statements could bemadeabout attainable uses in Lower Cuckels Brook:

-The restoration of aquatic life in Lower Cuckels Brook lmlted to someextent bythe small size and lower flow of the stream, bychannelization, andbycontaminants in suburban and highway runoff from the upstream watershed. Lower Cuckels Brook could support a limited macroinvertebrate community of generally tolerant species, and somesmall fish aswere found in the reference channelized subsection above the SRVSAdischarge (Stations 1and2). Unless it were altered or removed, the Calco Damcomplex would continue to prevent fish migration. Wildlife typical of narrow stream corridors could inhabit the generally narrow strips of land between Lower Cuckels Brook andnearby railroad tracks andwaste lagoons. Restoration of aquatic life in Lower Cuckels Brook would beexpected to have little impact onaquatic life in the Raritan River.

D-23Recreation -Lower Cuckels Brook would betoo shallow for swlmning or boating, and its small fish could not support sport flshlng. The industrial surroundings of Lower Cuckels Brook, Includjng waste lagoons and active manufacturing facilities and rallroads, severely reduces the potentlal for other recreational actlvlties such as streamside trails and pfcnlc areas, wading, and nature appreciation. As Lower Cuckels Brook is on private Industrial property, trespassing along thls brook and1nthe surroundlng area is discouraged.
It would appear unlikely that any of the landowners, or any government agency, would develop recreational facilities along lower Cuckels Brook oreven removesomeofthe brush which impalrs access to mostofthe Brook. Recreation along Lower Cuckels Brook would belimited, occasional, andinformal. Other Water Uses-Although water quality In Lower Cuckels Brook would generally meet FM-2Nontrout criteria, the volume of natural flow in Lower Cuckels Brook would be insufflc1ent for potable water supply orfor Industrjal oragricultural water use. In general, Lower Cuckels Brook would become a small channellzed tributary segnent flowing through aheavily industrlallzed area, free of gross pollution andcapable of supportlng amodest aquatlc community andvery limited recreatIona use. IV. SUMMARY

ANDCONCLUSIONS
This use-attainability analysis hasdiscussed the present impalnent of the currently designated uses of Lower Cuckels Brook, the role of wastewater discharges in such Impairment, and the extent to which currently designated water uses might be achieved If the wastewater discharges were removed. Further analysis, outside the scope of this survey, will berequired: to document the costs of removjng SRVSAand American Cyanamid effluent from Lower Cuckels Brook, and to evaluate the impact ofthe SRVSAandAmerican Cyanamld discharges onthe Raritan River. These analyses maylead to the development of site-specific water quality standards for Lower Cuckels Brook (designated uses llmited to the conveyance of wastewater and the preventlon of nuisances), or to the removal of the wastewater discharges from Lower Cuckels Brook. Ineither case, effluent limits would beestablished tc protect water quality Inthe Raritan River.

D-24WATERBODYSURVEYANDASSESSMENT DeepCreek AndCanal Creek Scotland Neck, North Carolina

I. INTRODUCTION
A. Site Description
TheTownofScotland Neckis located in Halifax County in the lower coastal plain of North Carolina. TheTown's wastewater, madeupmostly of domestic waste with asmall amount of textile waste, is treated in an oxidation ditch of 0.6 mgddesign capacity. Thetreatment plant is located two-tenths of amile southwest of Scotland Neckoff U.S. Highway 258, asseen in Figure 1.Theeffluent (0.323 mgdaverage) is discharged to Canal Creekwhich is atributary to DeepCreek. Canal Creek is achannelized stream which passes through anagricultural watershed, but also receives someurban runoff from the western sections of Scotland Neck. It is aClass Cstream with adrainage area of 2.4 square miles, anaverage stream flow of 3.3 cfs, anda7010of 0.0 cfs. TheCreek retains definite banks for about 900feet below the outfall atwhich point it splits into numerous shifting channels and flows BOOto 1400 feet through acypress swampbefore reaching DeepCreek. Curing dry periods the braided channels of Canal Creek can bevisually traced to DeepCreek. During wet periods Canal Creek overflows into the surrounding wetland andflow is nolonger restricted to the channels. DeepCreek is atypical tannin colored Inner Coastal Plain stream that has aheavily wooded paludal flood plain. Themain channel is not deeply entrenched. In somesections streamflow passes through braided channels, or maybeconveyed through the wetland bysheetflow. During dry weather flow periods the main channel is fairly distinct and the adjacent wetland is saturated, but not inundated. During wet weather periods the main channel is less distinct, adjacent areas become flooded and previously dry areas becomesaturated.
8. Problem Oefinition
TheTownof Scotland Neck is unable to meet its final NPDESPermit limits and is operating with aSpecial Order by Consent which specifies interim limits. TheTownis requesting a201Step III grant to upgrade treatment by increasing hydraulic capacity to 0.675 mgdwith anadditional clarifier, an aerobic digestor, tertiary filters, achlorine contact chamber, post aeration andadditional sludge drying beds. Thetreated effluent from Scotland Neck is discharged into Canal Creek. The lower reaches of Canal Creek are part of the swampthrough which DeepCreek passes.

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andCanal Creek

D-26DeepCreek carries a"C" classification, but dueto naturally lowdissolved

oxygen andother conditions imposed bythe surrounding swamp, it is felt that reclassification to "C-Swamp" should beconsidered. DeepCreek should beclassified C-Swampbecause its physical characteristics meetthe C-Swamp classification of the North Carolina Administrative Codefor Classifications andWater Quality Standards. TheCodestates: Swampwaters shall mean those waters which are sodesignated bythe Environmental Management Commission andwhich are topographically located soasto generally have very low velocities andcertain other characteristics which are different from adjacent streams draining steeper topograpy. The C-Swampclassification provides for aminimum pHof 4.3 (compared to arange of pH6.0 to pH8.5 for Cwaters), andallows for low(unspecified) DOvalues if caused bynatural conditions. 00 concentrations in Deep Creek are usually below 4.0 W/l. C. Approach to UseAttainability Analysis
1.Data Available
1. Self Monitoring Reports from Scotland Neck. 2. Plant inspections bythe Field Office. 3. Intensive Water Quality Survey of Canal Creek andDeepCreek at Scotland Neck In September, 1979. Study consisted of time-oftravel dyework andwater quality sampling.
2. Additional Routine Data Collected
Water quality survey of Canal Creek andDeepCreek at Scotland Neck in June 1982. Water quality data wascollected to support abiological survey ofthese creeks. Thestudy included grab samples andflow measurements.
Benthic macroinvertebrates were collected from sites onCanal Creek and Deep Creek. Qualitative collection methods were used. Atwomemberteamspent onehour per site collecting from asmanyhabitats aspossible. It is felt that this collection method is more reliable than quantitative collection methods (kicks, Surbers, ponars, etc.1 in this type of habitat. Taxa are recorded as rare, common, and abundant.
II. ANALYSESCONDUCTED
A. Physical Factors Sampling sites werechosen to correspond with sites previously sampled in a water quality survey of Canal andDeepCreeks. Three stations were selected onCanal Creek. SN-1 is located 40feet above the Townof Scotland Neck Wastewater Treatment Plant outfall. This site serves as areference station. Thewidth at SN-1 is 7.0 feet andthe average discharge (two flows were recorded in the September 1979 survey andoneflow in the June 1982

D-27survey) is 0.65 cubic feet per second. Canal Creek at SN-1hasbeenchannelized andhasasubstrate composed of sand andsilt. SN-4is located on Canal Creek 900feet below the discharge point. This section of Canal Creek has anaverage cross-sectional area of 11.8 feet and an average flow of 1.33 cubic feet per second. Thestream in this section is also channelized and also has asubstrate composed of sand andsilt. There is acanopy of large cypress at SN-4below the plant, while the canopy above SN-1is reduced to anarrow buffer zone. Thepotential usesof DeepCreek are limited byits inaccessability in these areas. Athird station (SN-5) wasselected ononeof the lower channels of Canal Creek at the confluence with DeepCreek 3200 feet upstream of the U.S. Highway 258 bridge. Discharge measurements could not be accomplished at this site during this survey because of the swampynature of the stream with manyill-defined, shallow, slow moving courses. Renthic macroinvertebrates were collected from this site. Three stations were chosen onDeepCreek. SN-6 is approximately 300feet upstream of SN-5onCanal Creek at its confluence with DeepCreek andis a reference site. SN-7is located at the U.S. Highway 258bridge andSN-8is located further downstream at the SR1100bridge. SN-7andSN-8are below Canal Creek. There are somedifferences in habitat variability amongthese three sites. Thesubstrate at both SN-6andSN-7is composed mostly of a deep layer of fine particulate matter. Usable andproductive benthic habitats in this area are reduced because of the fine particulate layer. It is possible that the source of this sediment is from frequent overbank flows and from upstream sources. Productive benthic habitats include areas of macrophyte growth, snags, andsubmerged tree trunks. Discharge measurements were not taken at anyof these three sites during this survey. B. Chemical Factors Chemical data fromtwowater qualit 6surveys showthat the dissolved oxygen in Canal Creek is depressed while B05,solids andnutrient levels are elevated. The1982study indicates, howeer, that the water quality is better than it wasduring the 1979survey. Suchwater quality improvements maybe due to the addition of chlorination equipment andother physical improvements aswell asto the efforts of anewplant operator.
Both above andbelow its confluence with Canal Creek, DeepCreek showspoor water quality which maybeattributed to natural conditions, but not to any influence fromthe waste load carried byCanal Creek. Canal Creek exhibited higher DOlevels than DeepCreek. C. Biological Factors
Theimpact ofthe effluent onthe fauna of Canal Creek is clear. A63percent reduction in taxa richness from 35at SN-1to only 13at SN-4 indicates severe stress asmeasured against criteria developed bybiologists of theWater Quality Section. Theoverwhelming dominance ofChironomus at SN-4

O-28is indicative of 

### alow00 level andhigh concentrations of organic matter.

Towhat extent this condition is attributable to the effluent orto natural swampconditions is not clear, Noimpact to the benthos of DeepCreek was discerned which could beattributed to the effluent.
III. FINDINGS DeepCreek is currently designated asaclass Cwarmwater fishery but due to naturally lowdissolved oxygen concentrations maynot beable to satisfy the class Cdissolved oxygen criteria. The00criterion for class Cwaters stipulates aminimum value of 4ppm,yet the DOin DeepCreek, in both the 1979andthe 1982studies, wasless than 4ppm.Thus fromthe standpoint of aquatic life uses, DeepCreek maynot beable to support the forms of aquatic life which are intended for protection under the class Cstandards. 

### Because of prevailing natural conditions, there are no higher potential uses ofDeepCreek than nowexist; yet because of prevailing natural conditions and in light of the results of this water body assessment, the Cswampuse designation appears to beamore appropriate designation under existing North Carolina Water Quality Standards.
Canal Creek is degraded bythe effluent from the Scotland Neckwastewater treatment plant. TheBOO 8,fecal coliform, solids andnutrient levels are elevated while the 00 cncentration is depressed. The reach immediately below the outfall is affected byanaccumulation of organic solids, bydiscoloration andbyodors associated with the wastewater.
IV. SUMMARY

ANDCONCLUSIONS
Thewater body survey of DeepCreek andCanal Creek included aconsideration of physical, chemical and biological factors. The focus of interest 

### wasthose factors responsible for water quality in DeepCreek, including possible deliterious effects of the Scotland Neckwastewater onthis water body. The

### analyses indicate that the effluent does not appear to affect DeepCreek. Instead, the water quality of DeepCreek reflects 

### natural conditions imposed by

### seasonal lowflow andhigh temperature, andreflects the nutrient andorganic contribution of the surrounding farmland andwetland. It is concluded that the C-Swampdesignation more correctly reflects the uses of DeepCreek than doesthe Cdesignation.
In contrast to DeepCreek, Canal Creek is clearly affected bythe treated effluent. Further examination would berequired to determine the extent of recovery that might beexpected in Canal Creek if the plant were to meet current permit requirements or if the proposed changes to the plant were incorporated into the treatment process.



### o-29WATERRODYSURVEYANDASSFSSMENT Malheur River Malheur County, Oregon
I INTRDDUCTIDh
A. Site Description
TheMalheur River, in southeastern Oregon, flows eastward to the Snake River which separates Dregon from Idaho. Most of Malheur County is under someform of agricultural production. With anaveraqe annual precipitation of less than 111inches, the delivery of irrigation water is essential to maintain the hiqh aqricultural productivity ofthe area. TheMalheur River system serves asamajor source ofwater for the area's irrigation requirements (out of basin transfer of water from Owyhee Reservoir augments the Malheur supply). Reservoirs, dams, and diversions have heen built on the Malheur and its tributaries to supply the irrigation network. The first major withdrawal occurs at the Namorf Damand Diversion, at Malheur River Mile 69. Figure 1presents a schematic ofthe study area. Irrigation water is delivered to individual farms by a complicated system of canals and laterals. Additional water is obtained from drainage canals andgroundwater sources. An inteqral part of the water distribution system is the useand reuse of frriqation return flows five or six times before it is finally discharqed tothe SnakeRiver. 

### R. Problem Definition
TheMalheur River above Flamorf Damand Diversion is managed primarily asatrout fishery, andfrom Namorf to the mouth as awarm-water fishery. Theupper portion of the river system is appropriately classified. Relow Namorf Dam,however, the river is inappropriately classified assupporting acold-water fishery, andtherefore wasselected for review. This review was conducted as part of the U.S. Environmental Protection Agency's field test of the draft "Water Body Survey and Assessment Guidance" for conducting a use attainability analysis. Theguidance document supports the proposed rule to revise and consolidate the existing regulation governing the development, review, and approval of water quality standards under Section 303of the Clean WaterAct.

c,. Approach to UseAttainability Analysis
Assessment ofthe Malheur River is basedonasite visit which included meetings with representatives of the Malheur County Citizen's Water Resources Committee, the USDA-Soil Conservation Service, the Dreqon Department of Environmental

U-30MIDDLE FORK OF MALHEUR RIVER
WARM SPRINGS RESERVOIR
SOUTH FORK RESERVOIR

ALHEUR RIVER MALHEUR RIVER -‘vf M

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## SIMPLIFIED FLOW SCHEMATIC MALHEUR RIVER IRRIGATION SYSTEM

-FIGURE I- D-31nualfty (DDEQ), the Oregon Department of Fish and Wildlife (CIDFW),and the U.S. Environmental Protection Agency (EPA): anduponthe findings reported in twostudies:
Final Report, TwoYear Sampling Program, Malheur County hater Duality Management Plan, Malheur County Planning dfffce, Vale, Oregon, 1981. Bowers, Hosford and Moore, Stream Surveys of the Lower OwyheeandMalheur Rivers, A-Report to the Malheur County Qater Resources Committee, Oregon Department of Fish and IJlldllfe, January, 1979.
Thefirst report, prepared under amendments to Section 208of the Clean Water Act, contains extensive information on the quantity, quality and disposition of the areas' water resources. The second document gives the fish populations found in the lower 69miles of the Malheur River during June and July, 1978. Information in the DDFW report is incorporated in the 208 report. Additional fisheries information supplied byDDFWwasalso considered.
A representative of DDEO, Portland, and the Water Duality Standards Coordinator, EPARegion X, Seattle, Washington, agreed that the data and analyses contained in these two reports were sufficient to re-examine existing designated uses of the Malheur River.
II ANALYSESCONDUCTED Physical, chemical, and biological data were reviewed to determine: (1) whether the attainment of asalmonid fishery was feasible in the lower Malheur; and (2) whether some other designated use would be more appropriate to this reach. The elements ofthis review follow: 

### A. Physical Factors Historically, salmonfd fish probably used the lower Malheur (lower SOmiles) mainly asamigration route, because of the warmwater and poor habitat. The first barrier to upstream fish migration wasthe Nevada Damnear Vale, constructed in 

### mn. Construction ofthe WarmSprings Damin 1918, endedthe anadromous fish runs in the Middle Fork Malheur. The construction of Reulah Damin 1931, befell the remainder of anadromous fish runs onthe North Fork Malheur. Finally, the construction of Brownlee Reservoir in 1958completely blocked salmonfd migrants destined for the upper Snake River System.

D-32With the construction of the major irrigation reservoirs on the Malheur River and its tributaries, the natural flow characteristics in the lower river have chanqed. Instead of high early summerflows, low summerandfall flows andsteady winter flow, the peak flows mayoccur in spring, if andwhen the upstream reservoirs spill. Also, ahigh sustained flow exists all summer as water is released from the dams for irrigation. Asignificant change limiting fish production in the Malheur River below Namorf is the extreme low flow that occurs when the reservoirs store water during the fall and winter for the next irrigation season. Two other physical conditions affect the maintenance of salmonids in the lower Malheur. One is the high suspended solids load carried to the river by irrigation return flows. High suspended solids also occur during wetweather when high flows erode the stream bank and re-suspend bottom sediments. The seasonal range of suspended solids content is pronounced, with the highest concentrations occurring during irrigation season andduring periods of wet weather. Observed peaks in lower reaches of the river, measured during the two-year 2D8 Program, reached 13DDmg/l, while hackground levels rarely dropped below 50mg/l. Ahigh suspended solids load in the river adversely affects the ability of sight-feeding salmonids to forage, and may limit the size of macroinvertebrate populations and algae production which are important to the salmonid food chain. Asecond factor is high summerwater temperature which severely stresses salmonids. The high temperatures result from the suspended particles absorbing solar radiation.
B. Riological Factors
The biological profile of the river is mainly based on fisheries information, with some macroinvertebrate samples gathered bythe Oregon Department of Fish andWildlife (ODFW) in 1978. During the site visit, the participants agreed additional information on macroinvertebrates and periphyton would not be needed because the aquatic insect numbers and diversity were significantly greater in the intensively irrigated reach of the river than for the upper river where agricultural activity is sparse. Although the Malheur River from Namorf tothe mouth is managed asawarmwater fishery, ODFWhasexpended little time andfew resources onthis stretch of the river because it is not a productive fish habitat. Survey results in summerof 1978 showed alow ratio of gamefish to rough fish over the lower 69miles ofthe Malheur River.

D-33In the section between Namorf and the Gellerman-Froman Diversion Damthere was little change in water quality although water temperatures were elevated. fish were Only three game

captured but non-game fish sight-feeders were cornnon. Lowwinter flows over astreambed having few deep pools for overwinter survival appears to limit fish production in this reach of river.
In the stretch from the Gellenan-Froman Diversion to the mouth, the river flows through a region of intensive cultivation. Theriver carries ahigh silt load which affects sight-feeding fish. Low flows immediately below the Gellerman-Froman Damalso limit fish production in this area.

c s. Chemical Factors
Aconsiderable amount of chemical data exist on the Malheur River. However, since the existing andpotential uses of the river are dictated largely byphysical constraints, dissolved oxygen was the only chemical parameter considered in the assessment.
The Dissolved Oxygen Standard established for the Malheur River Rasin calls for aminimum of 7Spercent of saturation at the seasonal low and 95 percent of saturation in spawning areas orduring spawning, hatching, andfry stages of salmonid fishes. One sample collected at Namorf fell below the standard to 73percent of saturation or8.3 mg/l in Novemher, 1970. All other samples were ahove this content, reaching as high as 170percent of saturation during the summerdue to algae. Data collected bythe DDE0from Malheur River near the mouth between 1976 and 1979 showed the dissolved oxygen content ranged from 78 to 174 percent saturation. The dissolved oxygen content in the lower Malheur River is adequate to support awarm-water fishery.
III FIN@INGS 

### A. Existing Uses
The lower Malheur River is currently designated asasalmonid fishery, but it is managedasawarmwater fishery. Dueto a number of physical constraints onthe lower river, conditions are generally unfavorahle for game fish, so rough fish predominate. In practice, the lower Malheur River serves asa source and asink for irrigation water. This type of use contributes to water quality conditions which are unfavorable to salmonids.

D-348. Potential JJses
Salmonfd spawning and rearing areas generally require the highest criteria of all the established beneficial uses. It would be impractical, if not impossible in someareas, to improve water quality to the level required by salmonids. However, even if this could be accomplished, high summer temperatures and seasonal low flows would still prevail. While salmonids historically movedthrough the Malheur River to spawn in the headwater areas, year-round resident fish populations probably did not exist in someof these areas at the time.
TheMalheur River basin can bedivided into areas, based upon differing ma,ior uses. Suggested divisions are: (1) headwater areas above the reservoirs; (2) reservoirs; (3) reaches below the reservoirs andabove the intensively irrigated areas: (4) intensively irrigated areas; and (5) the SnakeRiver.
In intensively irrigated areas, criteria should reflect the primary useofthe water. Higher levels of certain parameters ife.ee;,;;;;ended :qrlJ$;, nutrfen:;ic;emperature, etc.) should

ln areas lntenslvely irrigated agriculture, even under ideal conditions, will unavoidably contribute higher levels of these parameters. Criteria, therefore, should bebased onthe conditions that exist after Rest Management Practices have beenimplemented.
IV SUMMARY

ANDCONCLUSIONS
Malheur River flows have been extensively altered through the construction of several damsanddiversion structures designed to store anddistribute water for agricultural uses. These dams, as well as others on the Snake River, to which the Malheur is tributary, block natural fish migrations in the river and, thus, have permanently altered the river's fisheries. In addition, water quality below Namorf Damhas been affected, primarily through agricultural practices, in awaywhich severely restricts the type of fish that can successfully inhabit the water. One important factor which affects fish populations below Namorf is the high suspended solids loading which effectively selects against sight-feeding species. Other conditions which could affect the types andsurvival of fish species below Namorf include low flow during the fall and winter when reservoirs are being filled in preparation for the coming irrigation season, aswell ashigh suspended solids, andhigh temperatures during the summer irrigation season. Realistically, the Malheur River could not be returned to its natural state unless alarge number of hydraulic structures were removed. Removal of these structures would result in the demise of agriculture in the region, which is the mainstay of the

D-35county's economy. Furthermore, removal ofthese structures is out of the question due to the legal water rights which have been established in the region. These water rights can only be satisfied through the system of dams, reservoirs, and diversions which have been constructed in the river system. Thus, the changes in the Malheur River Basin are irrevocable. Physical barriers to fish migration coupled with the effects of hiqh sediment loads and the hydraulics of the system have for years established the uses of the river. Given the existing conditions and uses of the Malheur River below the Namorf Diversion, classification of this river each should be changed from a salmonid fishery, a use that cannot be achieved, to achievable uses which are based on the existing resident fish populations and aquatic life to reflect the present and highest future uses of the river. Suchachange in designated beneficial uses would not further jeopardize existing aquatic life in the river, norwould it result in anydegradation in water quality.

D-36WATERBODYSURVEYANDASSESSMENT Pecan Bayou Brownwood, Texas

I. INTRODUCTION
A. Site Description Segment 1417 of the Colorado River Basin (Pecan Bayou) originates below the Lake Brownwood Damand extends approximately 57.0 miles to the Colorado River (Figure 1). The Lake Brownwood Damwas completed in 1933. Malfunction of the dam's outlet apparatus led to its permanent closure in 1934. Since that time, discharges from the reservoir occur only infrequently during periods of prolonged high runoff conditions in the watershed. Damseepage provides the base flow to Pecan Bayou (Segment 1417). The reservoir is operated for flood control and water supply. The Brown County WIDtransports water from the reservoir via aqueduct to Brownwood for industrial distribution, domestic treated water distribution to the Cities of Brownwood and Bangs and the Brookesmith Water System, and irrigation distribution. Someirrigation water is diverted from the aqueduct before reaching Brownwood.
Pecan Bayou meanders about nine miles from Lake Brownwood to the City of Brownwood. Twosmall dams impound water within this reach, and Brown County WIDoperates anauxilliary pumping station in this area to supply their system during periods of high demand.
Two tributaries normally provide inflow to Pecan Bayou. Adams Branch enters Pecan Bayou in Brownwood. The base flow consists of leaks and overflow in the Brown County WID storage reservoir and distribution system. Willis Creek enters Pecan Bayou below Brownwood. The base flow in Willis Creek is usually provided by seepage through a soil conservation dam.
The main Brownwood sewage treatment plant discharges effluent to Willis Creek one mile above its confluence with Pecan Bayou. Sulfur Draw, which carries brine from an artesian salt water well and wastewater from the Atchison, Topeka and Santa FeRailroad Co., enters Willis Creek about 1,700 feet below the Brownwood sewage treatment plant. Below the Willis Creek confluence, Pecan Bayou meanders about 42.6 miles to the Colorado River, and receives no additional inflow during dry weather conditions. Agricultural water withdrawals for irrigation may significantly reduce the streamflow during the growing season.
The Pecan Bayou drainage basin is composed primarily of range and croplands. The stream banks, however, are densely vegetated with trees, shrubs and grasses. The bayou is typically lo-65 feet wide, 2-3 feet deep, and is generally sluggish in nature with soft organic sediments.

D-37BROWNWOOO -- -- ---

Figure 1 PECANBAYOUSEGMENTMAP

D-37AB. Problem Definition
The designated water uses for Pecan Bayou include noncontact recreation, propagation of fish and wildlife, and domestic raw water supply. Criteria for dissolved oxygen (minimum of 5.0 mg/l), chlorides, sulfates, and total dissolved solids (annual averages not to exeed 250, 200, and 1000mg/l, respectively), pH(range of 6.5 to 9.0) fecal coliform (log mean not to exceed lOOO/lOO ml), and temperature (maximum of 9D°F) have been established for the segment. Historically, Pecan Bayou is in generally poor condition during Sumner periods of low flow, when the Brownwood STP contributes a sireable portion of the total stream flow. During low flow conditions, the stream is in ahighly enriched state below the sewage outfall. Existing data indicate that instream dissolved oxygen concentrations are frequently less than the criterion, and chloride and total dissolved solids annual average concentrations occasionally exceed the estahlfshed criteria. The carbonaceous and nitrogenous oxygen deficencies in Pecan Bayou. The major cause of elevated chlorides in Pecan Bayou is the artesian brine discharge in to Sulfur Draw.
Toxic compounds (PCB, DDT, DDD, DDE, Lindane, Heptachlor epoxide, Dieldrin, Endrin, Chlordane, Pentachlorophenol, cadmium, lead, silver, and mercury) have been observed in water, sediment and fish tissues in Pecan Bayou (mainly below the confluence with Willis Creek). It has been determined that the major source was the Brownwood STP, but attempts to specifiy the points of origin further have been unsuccessful. However, recent levels show adeclining trend. C. Approach to UseAttainability
Assessment of Pecan Bayou is based on asite visit which included meetings with representatives of the State of Texas, EPA(Region VI and Headquarters) and Camp Dresser & McKee Inc., and upon information contained in anumber of reports, memosand other related materials.
It was agreed bythose present during the site visit that the data and analyses contained in these documents were sufficient for an examination of the existing designated uses of Pecan Bayou.
II. ANALYSESCONDUCTED
Anextensive amount of physical, chemical, and biological data has been collected on Pecan Bayou since 1973. Most of the information was gathered to assess the impact of the Brownwood STPon the receiving stream. In order to simplify the presentation of these data, Pecan Bayou was divided into three zones (Figure 1): Zone 1is the control area and extends from the Lake Brownwood Dam(river mile 57.0) to the Willis Creek confluence (river mile 42.6): Zone 2is the impacted area and extends 9.n miles below the Willis Creek confluence.
D-38A. Physical Evaluation
With the exception of stream discharge, the physical characteristics of Pecan Bayou are relatively homogeneous byzone. Average width of the stream is about 44-511 feet, and average depth ranges from 2.1 to 3.25 feet. The low gradient (2.8 to 3.9 ft/mile) causes the bayou to besluggish (average velocity of about 0.1 ft/sec), reaeration rates to be low (K2 of 0.7 per day at 20°C). and pools to predominate over riffles (965 to 4Y). Stream temperature averages about 18°C and ranges from l-32°C. The substrate is composed primarily of mud (sludge deposits dominate in Zone 2), with small amounts of bedrock, gravel and sand being exposed in riffle areas.
Rase flow in Pecan Bayou is provided bydamseepage (Zone 1) and the treated sewage discharge from the City of Brownwood (Zones 2and 3). Median flow increases in adownstream direction from 2.5 cfs in Zone 1to 17.4 cfs in Zone 3. Significantly higher mean flows (118 cfs in Zone 1and 125 cfs in Zone 3) are'the result of periodic high rainfall runoff conditions in the watershed.
B. Chemical Evaluation Existing chemical data of Pecan Bayou characterize the degree of water quality degradation in Zone 2. Average dissolved oxygen levels are about 2.0 mg/l lower in the impact zone, and approximately 50?of the observations have been less than 5.0 mg/l. BOD5, ammonia, nitrite, nitrate, and phosphorus levels are much hiqher in the impact zone as compared to the control and recovered zones. Iln-ionized amonia levels are also higher in Zone 2, but most of the concentrations were below the reported chronic levels allowable for warm water fishes. None of the levels exceeded the reported acute levels allowable for warmwater fishes, and less than 4:!of the levels were between the acute and chronic levels reported. Total dissolved solids, chlorides and sulfates were higher in Zones 3and 3, mainly as aresult of the hrine and sewage discharges into Sulfur Draw and Willis Creek.PCR, DDT, DDD,DDEand Lindane in water, and PCB, DDD,and DDE, Heptachlor epoxide, Dfeldrfn, Endrin, Chlordane, and Pentachlorophenol in sediment have been detected in Zone 2. PCB, DDT, DDD,andDDE concentrations in water have exceeded the criteria to protect freshwater aquatic life. The Rrownwood STPwas the suspected major source of these pesticides. Most of the recent levels, however, show a declining trend. PCBwas detected also in Zones 1and 3. Heavy metals have not been detected in the water. Heavy metals in the sediment have shown the hlghest levels in Zone 2for arsenic (3.7 mq/kq), cadmfun (1.1 mg/kg), chromiun (17.4 mg/kg), copper (9.5 mg/kg), lead (25.1 mg/kg), silver (1.5 mg/kg), zinc (90 mg/kg), and mercury (0.18 mg/kd.

D-39C. Biological Evaluation
Fish samples collected from Zone 1are representative of afairly healthy population of gamefish, rough fish and forage species. Zone 2 supported asmaller total number of fish which were composed primarily of rough fish and forage species. Arelatively healthy balance of game fish, rough fish and forage species reappeared in the recovered zone. Macrophytes were sparse in Zones 1and 3. They were most abundant in Zone 2 below the Willis Creek confluence and were composed of vascular plants (pondweed, coontail, false loosestrife and duckweed) and filamentous algae (Clad0 hora and + abundance below Willis Cree smost of the area from the Brownwood STP.
Zone 1is represented by afairly diverse macrobenthfc community characteristic of a clean-water mesotrophic stream. Nutrient and organic enrichment in Zone 2 has a distinct adverse effect as clean-water organisms are replaced by pollution-tolerant forms. Some clean-water organisms reappeared in Zone 3and pollution-tolerant forms were not as prevalent; however, recovery to baseline conditions (Zone 1) was not complete.
Net phytoplankton desnities are lowest in Zone 1. Nutrient and organic enrichment in Zone 2promotes amarked increase in abundance. Peak abundance was observed in the upper part of Zone 3. The decline below this area was probably caused by biotic grazing and/or nutrient deficiencies.
Fish samples for pesticides analyses have revealed detectable levels of PCB, DDEand DDDin Zone 1. Fish collected from zone 2 contained markedly higher amounts of DDE, DDO, DDT, Lfndane and Chlordane than Zones 1or 3. PCBin fish tissue was highest in ZOne3, and measureable concentrations of DDEand DDDhave also been observed. Concentrations of total DDT in whole fish tissues from Zone 2 have exceeded the USFDAAction Level of 5.0 mg/kg for edible fish tissues. Species representing the highest concentrations. Computer modeling simulation were made to predict the dissolved oxygen profile in the impact zone during the fish spawning season. The results indicate that about three miles of Pecan Bayou in April and May and about 4 l/2 miles in June will be unsuitable for propogatfon, considering aminimum requirement of 4.0 mg/l. The model predicts a minimum D.O. of 0.8 mg/l in April, 1.2 mg/l in May, and 0 mg/l in June.

D-40D. Institutional Evaluation
Two institutional factors exist which constrain the situation that exists in Pecan Bayou. These are the irrigation water rights and the Brownwood sewage treatment plant discharge permits. Although the sewage treatment plant discharge permits will expire and the problems created by the effluent could be eliminated in the future, there is a need for the flow provided by the discharge to satisfy the downstream water rights used for irrigation. Currently, there are eight water users on Pecan Bayou downstream of the Brownwood STPdischarge with water rights permits totaling 2,957 acre-feet/year. Obviously, the 0.1 cfs base flow which exists in Pecan Bayou upstream of the STPdischarge is not sufficient to fulfill these downstream demands. Therefore, it appears that the STPflow may be required to supplement the base flow in Pecan Bayou to meet the downstream demands for water unless it could be arranged that water from Lake Brownwood could be released by the Brown Co. WID$1to meet the actual downstream water needs. Modeling studies show that although there would be some improvement in water quality as aresult of the sewage treatment plant going to advanced waste treatment (AWT), there would still be D.O. violations in a portion of Pecan Bayou in Zone 2. The studies also show that there is minimal additional water quality improvement between secondary and advanced waste treatment, although the costs associated with AWT were significantly higher than the cost for secondary treatment. In this case, the secondary treatment alternative would be the recorrmended course of action.
III. FINDINGS
A. Existing Uses
Pecan Bayou is currently being used in the following ways:

oDomestic RawWater Supply oPropagation of Fish and Wildlife ' Noncontact Recreation 0Irrigation OCity of Brownwood STPdischarge (not an acceptable or approved use designation)
Use as adischarge route for the City of Brownwood's sewage treatment plant effluent has contributed to water quality conditions which are unfavorable to the propagation of fish and wildlife in a portion of Pecan Bayou.
B. Potential Uses
The Texas Department of Water Resources has established water uses which are deemed desirable for Pecan Bayou. These uses include: noncontact recreation, propagation of fish and wildlife, and domestic raw water supply.

n-41Ofthese uses, propagation of fish and wildlife is unattainable in

a portion of Pecan Rayou due to the effects of low dissolved oxygen levels in the bayou primarily during the spawning season. If the Brownwood sewage treatment plant effluent could be removed from Pecan Bayou, the persistently low dissolved oxygen conditions which exist and are unfavorable to fish spawning could be alleviated and the propagation of fish and wildlife could be partially restored to Pecan Bayou.
Public hearings held on the proposed expansion of the sewage treatment plant indicate a reluctance from the public and the City to pay for higher treatment levels, since modeling studies show minimal water quality improvement in Pecan Bayou between secondary and advanced waste treatment. In addition, an affordability analysis performed by the Texas Department of Water Resources (Construction Grants) indicates excessive treatment costs per month would result at the AWTlevel.
It appears that the elimination of the waste discharge from Pecan Bayou is not presently afeasible alternative, since the Brownwood STP currently holds adischarge permit and the water rights issue seems to bethe overriding factor. Therefore, in the future, the uses which are most likely to exist are those which exist at present.
IV. SUMMARYANDCONCLUSIONS
Asummary of the findings from the use attainability analysis are listed below:
O The designated use "propagation of fish and wildlife" is impaired in Zone 2of Pecan Bayou.
' Advanced Treatment will not attain the designated use in Zone 2, partially because of low dilution, naturally sluggish characteristics (X velocity 0.1 ft/sec) and as a result, low assimlitive capacity of the bayou (K2 reaeration rate 0.7 per day at 20°C).

0 Downstream water rights for agricultural irrfgati on are significant.
' Dissolved oxygen levels are frequently less than the criterion of 5.0 mg/l in Pecan Bayou.
' Total DDTin whole fish from Zone 2exceeded the U.S. Food and Drug Administration's action level of 5.0 mg/kg for edible fish tissues.
' Annual average chloride concentrations in Pecan Bayou are occasionally not in compliance with the numerical criteria.

n-42Dissolved oxygen levels less than 5.0 mg/l (about 50% of the measurements) observed in Zone 2of Pecan Bayou result from the organic and nutrient loading contributed by the Brownwood STP and the corresponding low waste assimilative capacity of the bayou. As previously mentioned, the major source of toxics found in the water, sediment and fish tissues was also determined to bethe Brownwood STP. PCBand DDTin water have exceeded the criteria to protect freshwater aquatic life in Zone 2. Although the toxics appear to be declining in the water and sediment, the levels of total DDT found in whole fish exceed the U. S. Food and Drug Administration's action level (5.0 mg/k) for DDT in edible fish tissue. Investigations are underway by the Texas Department of Water Resources to further evaluate the magnitude of this potential problem. Primarily as a result of the oxygen deficiencies and possibly be cause of the presence of toxic substances, the designated use "propagation of fish and wildlife" is not currently attained in Zone 2 of Pecan Bayou. These problems could be eliminated only if the Brownwood STPceased to discharges into Pecan Bayou because even with advanced waste treatment the water quality .of the receiving stream is not likely to improve sufficiently to support this designated use. Other treatment alternatives such as land treatment or overland flow are not feasible because of the current discharge is necessary to satisfy downstream water rights for agricultural irrigation. If the flow required to meet the water rights could be augmented from other sources, then the sewage treatment plant discharge could be eliminated in the future.
The annual average chloride level in Pecan Bayou are occasionally not in compliance with the established criterion. The primary source has been determined to be aprivately owned salt water artesian well. Since efforts to control this discharge have proved futile, some consideration should be given to changing the numerical criterion for chlorides in Pecan Bayou.
In conclusion, it appears that either the Brownwood STPdischarge into Pecan Bayou should be eliminated (if an alternative water source could befound to satfsy the downstream water rights) or the numerical criterion for dissolved oxygen and the propogatfon of fish and wildlife use designation should bechanged to reflect attainable conditions.

D-43WATERBODYSURVEYANDASSESSMENT Salt Creek Lincoln, Nebraska

I. INTRODUCTION
A. Site Description
The Salt Creek drainage basin is located in east central Nebraska. The mafnstem of Salt Creek originates in southern Lancaster County and flows northeast to the Platte River (Figure 1). Ninety percent of the 1,621 square mile basin is devoted to agricultural production with the remaining ten percent primarily urban. The basin is characterized by moderately to steeply rolling uplands and nearly level to slightly undulating alluvial lands adjacent to major streams, primarily Salt Creek. Drainage in the area is usually quite good with the exception of minor problems sometimes associated with alluvial lands adjacent to the larger tributaries. Sof.ls of the basin are of three general categories. Loessfal soils are estimated to make up approximately 60 percent of the basin, glacial till soils 20 percent, and terrace and bottomland soils 20percent. Frequent high intensity rainfalls and increased runoff from land used for crop production has, in past years, contributed to flood damage in Lincoln and smaller urbanized areas downstream. To help alleviate these problems, flood control practices have been installed in the watershed. These practices, including several impoundments and channel modifications to the mainstream of Salt Creek, were completed during the late 1960’s. Channel realignment of the lower two-thirds of Salt Creek has decreased the overall length of Salt Creek by nearly 34 percent (from 66.9 to 44.3 miles) and increased the gradient of the stream from 1.7 feet/mile to 2.7 feet/mile.
Salt Creek is currently divided into three classified segments: (upper reach) LP-4, (middle reach) LP-3a, and (lower reach) LP-3b. (Figure 1). Segments LP-4 and LP-3b are designated as Warmwater Habitats whereas segment LP-3a is designated as a Limited Warmwater Habitat.
B. Problem Definition
"Warmwater Habitat" and "Limited Warmwater Habitat" are two subcategories of the Fish and Wildlife Protection use designation in the Nebraska Water Quality Standards. The only distinction between these two use classes is that for Limited Warmwater Habitat waters, reproducing populations of fish are "... l.imited by irretrievable maninduced or natural background conditions." Although segment LP-3a is classified Limited Warmwater Habitat and segment LP-3b as Warmwater Habitat, they share similar physical characteristics. Since the existing fisheries of both segments were not thoroughly evaluated when the standard was revised, it is possible that the use designation for one or other segments is incorrect. This study was initiated to determine (1) if the Warmwater Habitat use is attainable for segment LP-3a and (2) what, if any, physical habitat or water quality constraints preclude the attainment of this use.

U-44/ Y!' I

..C USGSStation

Fish Sampling (Maret, 1978) Site

* Macroinvertebrat: Sampling Site (Pesek, 1974)

Figure 1. Monitorir,g sites fromwhich data were used for Salt Creek

attainability study. --

D-45C. Approach to Use Attainability Analysis
The analytical approach used in this study was a comparison of physical, chemical and biological parameters between the upper, middle, and lower Salt Creek segments with emphasis was on identifying limiting factors in the creek. The uppermost segment (LP-4) was used as the standard for comparison.
The data base used for this study included United States Geological Survey (USGS) and Nebraska Department of Environmental Control (NDEC) water quality data outlined in the USEPASTORETsystem, two Master of Science theses by TomPesek and Terry Maret, publications from the Nebraska Game and Parks Commission and USGSand personal observations by NDECstaff. Nonewdata was collected In the study.
II. ANALYSESCONDUCTED
A review of physical, chemical and biological information was conducted to determine which aquatic llfe use designations would be appropriate. Physical characteristics for each of the three segments were evaluated and then compared to the physical habitat requlrements of important warm water fish species. Characteristics limiting the fishery population were identlfied and the sultability of the physical habitat for maintaining avalued fishery was evaluated. General water quality comparisons were made between the upper reach of Salt Creek, and the lower reaches to establish water quality differences. Awater quality index developed by the NDECwas used in this analysis to compare the relative quality of water in the segments. In addition, some critical chemical constituents required to maintain the important species were reviewed and compared to actual instream data to determine if water quality was stressing or precluding their populations.
The fish data collected by Maret was used to define the existing flshery population and composition of Salt Creek. This data was In turn used to determine the quality of the aquatic biota through the use of six biotic integrity classes of fish connunities and the Karr Index tentative numerical Index for defining class boundaries.
Macroinvertebrate data based on the study conducted by Pesek was also evaluated for density and diversjty.
III. FINDINGS
Chemical data evaluated using the Water Quality Index indicated good water quality above Lincoln and degraded water quality at and below Lincoln. Non-point source contributions were identified as a cause of water quality degradation and have been Impljcated in fish kills in the stream. Dissolved solids in Salt Creek were found to be considerably higher than in other streams in the State. Natural background contributions are the major source of dissolved solids load to the stream. Water quality criteria violations monitored in Salt Creek during lo80 and 1981were restricted to unionized arrmonia and may

D-46have adversely impacted the existing downstream fishery. Toxics which occasionally approach or exceed the EPA criteria are chromium and lindane. Since EPAcriteria for both parameters are based on some highly sensitive organisms which are not representative of indigenous populations typically found in Nebraska, the actual impact of these toxics is believed to beminimal.
Channelization was found to bealimiting factor in establlshing a fishery in middle and lower Salt Creek. Terry Maret, in his 1977 study, found that substrate changes from silt and clay in the upper non-channelized area to primarily sand in the channelized area causing substantial changes in fish comunities. The Habitat Suitability Index (HSI) developed by the Western Energy and Land Use Team of the U.S. Fish and Wildlife Service was used to evaluate physical habitat impacts on one important species (Channel Catfish) of fish in Salt Creek. The results indicated that upper Salt Creek had the best habitat for the fish investigated and middle Salt Creek had the worst. These results support the conclusion that middle Salt Creek lacks the physical habitat to sustain avalued warm water fishery. The Karr numerical index used to evaluate the fish data revealed that none of the stations rated above fair, further indicating the fish community is significantly impacted by surrounding rural and urban land uses. Analysis of the abundance and diversity of macroinvertebrates Indicated that the water quality in Salt Creek became progressively more degraded going downstream. Stations in the upper reaches were relatively unpolluted as characterized by the highest number of taxa, the greatest diversity and the presence of "clean-water" organisms.
IV. SUMMARYANDCONCLUSIONS
Based on the evaluation of the physical, chemical and biological characteristics of Salt Creek, the following conclusions were drawn by the State for the potentlal uses of the various segments: 1) Current classifications adequately define the attainable uses for upper and middle Salt Creek. 2) The Warmwater Habitat designated use may be unattainable for lower Salt Creek. 3) Channelization has limited existing instream habitat for middle Salt Creek. Instream habitat improvement in middle Salt Creek could increase the fishery but would lessen the effectiveness of flood control measures. Since flood control benefits are greater than any benefits that could be realized by enhancing the fishery, instream physical habitat remalned the limiting factor for the fishery. 4) Existing water quality does not affect the limited Warmwater Habitat classification of middle Salt Creek.

D-475) Uncontrollable background source impacts on existing water quality and the effects of channelization on habitat maypreclude attainment of the classified use.
The recommendations of the State drawn from these conclusions are as follows: 1) Keep upper section classification of Warmwater Habitat and middle section classification of Limited Warmwater Habitat. 2) Consider changing the lower section to aLimited Warmwater Habitat because of limited physical habitat and existing water quality.

D-48WATERBODYSURVEYANDASSESSMENT South Fork Crow River Hutchinson, Minnesota
I. INTRODUCTION
A. Site Description
The South Fork Crow River, located in south-central Minnesota, drains awatershed that covers approximately 1250 square miles. This river joins with the North Fork Crow to form the mainstem Crow River which flows to its confluence with the Mississippi River (Figure 1). Within the drainage basin, the predominant land uses are agricultural production and pasture land. The major soil types in the watershed are comprised of dark-colored, medium-to-fine textured silty loams, most of which are medium to well drained in character.
The physical characteristics of the South Fork Crow River are typical of many Minnesota streams flowing through agricultural lands. The upper portions of the river have been extensively channelized and at Hutchinson a forty foot wide, 12 foot high dam forms a reservoir west of the city. Downstream of the damthe river freely meanders through areas with light to moderately wooded banks to its confluence with the North Fork River Crow River. The average stream gradient for this section of the river is approximately two feet per mile and the substrate varies from sand, gravel and rubble in areas with steeper gradients to asilt-sand mixture in areas of slower velocities.
The average annual precipitation in the watershed is 27.6 inches. The runoff is greatest during the spring and early Sumner, after snowmelt, when the soils are generally saturated. Stream flow decreases during late Sumner and fall and is lowest in late winter. Small tributary streams in the watershed often go dry in the fall and wlnter because they have little natural storage and receive little ground water contribution. The seven-day ten year low flow condition for the South Fork below the dam at Hutchinson is approximately 0.7 cubic feet per second.
B. Problem Definition
The study on the South Fork Crow River was conducted in order to evaluate the existing fish community and to determine if the use designations are appropriate. At issue is the 28 fisheries and recreational use classification at Hutchinson. Is the water use classification approprlate for this segment? C. Approach to Use Attainability
The analysis utilized an extensive data base compiled from data collected by the Minnesota Pollution Control Agency (MPCA), Minnesota Department of Natural Resources (MDNR) and United States Geological Survey (USGS). Nonew data was collected as part of the study. The USGSmaintains partial or continuous flow record statlons onboth forks

D-49STATtONLOCATIONSFORTHESOUTHFORK CROWRIVERUSEATfAlNABlLlTY STUDY

A

a 0 ~I8ctrObhq Slollon USGSContmuour Ruordlng GOUQI"OStotlon USGSPottiol RecordStar’&

\ 

## i

D-50and the mainstem Crow River with adata base of physlcal and chemical parameters available on STORET. The USGSdata was used in the physical evaluation of the river. MPCAhas awater quality monitoring data base on STORETfor five stations In the Crow River watershed. The MPCAdata plus analytical data from awaste load allocation study on the South Fork below Hutchinson was used in the chemical evaluation of the river. MDNRfisheries and stream survey data, aMDNRreport onthe analysis of the composition of fish populations in Minnesota rivers, and personal observations of MDNRpersonnel was used to evaluate the biological characteristics of the river.
The analytical approach used by the MPCAsought to 1) compare instream fish community health of the South Fork to that of the North Fork, the mainstem Crow River, and other warmwater rivers in the State and 2) evaluate physical and chemical factors affecting fisheries and recreational uses. The North Fork of the Crow River was used for comparison because of sufficient fisheries data, similar land uses and morphologies, slmilar non-point source impacts and the lack of any significant point source dischargers.
II. ANALYSESCONDUCTED Physical, chemical and biological factors were considered in this use attainability analysis to determine the biological health of the South Fork and to define the physical and chemical factors which maybe limiting. Ageneral assessment of the habitat potentials of the South Fork Crow River was performed using ahabitat evaluation rating system developed by the Wisconsin Department of Natural Resources. In addition, the Tennant method for determining instream flow requirements was also employed in this study.
Fish species diversity, equitability and composition were used to define the biological health of the South Fork relative to that of the North Fork, the mainstem Crow and other warmwater rivers in Minnesota. Water quality monitoring data from stations above and below the point source discharges at Hutchinson were used to compare beneficial use impairment values pertaining to the designated fisheries and recreational uses of the South Fork Crow River. A computer data analysis program developed by EPARegion VIII was used to compute these values.
III. FINDINGS
The comparison of species diversity values for the North Fork and mainstem Crow River to the South Fork showed higher values for the North Fork and mainstem Crow. Onthe other hand, the South Fork had higher species equitability values. The percent species composition compared favorably to Peterson's (1975) estimates for median species diversity for alarger Minnesota river. Recruitment from tributaries, marshes, lakes and downstream rivers has given the South Fork a relatively balanced cotnnunity which compares well to other warmwater rivers in the State. The calculated species diversity and equitability indices coupled with the analysis of species composition indicated that the South Fork af the Crow River does support awarmwater fishery with evidence of somedegree of environmental stress.

D-51The MPCAemployed the Wisconsin habltat ratlng system and the Tennant

method designated to quantify minimum Instream flsherles flow requirements to identlfy any physical llmitlng factors. Based on the Wisconsin habitat evaluation assessment, habitat ratlng score were fair. The llmitlng factors Identified via thls assessment were: 1) lack of diverse streambed habltat suitable for reproduction, food production and cover and 2) instream water fluctuations (low flow may beamajor controlling factor).
The State utilized EPA Region VIII’s data analysis program to express stream water quality as a function of beneficial use. The closest downstream statlon to Hutchinson had the highest warmwater aquatic life use impalrment values. Warmwater aquatlc life use impairment values declined further downstream indicating that the point source dischargers were major contributors to thls use impairment. However, primary contact recreatlonal use impairment values were high throughout the stream, Thls led the State to believe that the impairment of primary contact recreational use Is attrlbutable to non-point sources.
IV. SUMMARYANDCONCLUSION
The State concluded from the study that: 1) the South Fork of the Crow River has adefinite fisheries value although the use impairment values indicate some stress at Hutchinson on an already limlted resource and 2) although the South Fork of the Crow River has a dominant rough fish population, game and sport fish present are important component species of this rivers' overall cofmnunity structure.
From these conclusions the State recommended that the South Fork of the Crow River retain its present 28flsheries and recreational use classification. Furthermore, efforts should continue to mitigate controllable factors that contribute to impairment of use. The effort should entail areduction of marsh tilling and drainage, acceptance and implementatlon of agricultural BMP's and an upgrade of point source dischargers in Hutchfnson.

D-52WATERBODYSURVEYANDASSESSMENT
South Platte River Denver, Colorado

I. INTRODUCTION
A. Site Description Segment 14 of the South Platte River originates north of the Chatfield Lake at Bowles Avenue in Arapahoe County and extends approximately 16 miles, through metro Denver, in anortherly direction to the Burlington ditch diversion near the Denver County-Adams County line. Amapof the study area Is presented in Figure 1. Chatfield Lake was originally constructed for the purposes of Flood control and recreation. The reservoir is owned by the U.S. Army Corps of Engineers and is essentially operated such that outflow equals inflow, upto amaximum of 5,nDD cfs. In addition, water is released to satisfy irrigation demands as authorized hy the State Engineers Office. There Is also an informal agreement between the State Engineers Office and the Platte River Greenway Foundation for timing releases of water to increase flows during periods of high recreational use. The Greenway Foundation has played an important role in the significant improvement of water quality in the South Platte River.
There are several obstructions throughout Segment 14 including low head dams, kayak chutes (at Confluence Park and 13th Avenue), docking platforms, and weir diversion structures which alter the flow in the South Platte River. There are four major weir diversion structures in this area which divert flows for irrigation; one is located adjacent to the Columbine Country Club, asecond near Union Avenue, athird upstream from Oxford Avenue, and afourth at the Burlington Ditch near Franklin Street. Significant dewatering of the South Platte River can occur due to instream diversions for irrigation and water supply and pumping from the numerous ground water dwells along the river. Eight tributaries normally provide inflow to the South Platte River in Segment 14. These include Big Dry Creek, Little Dry Creek, Bear Creek, Harvard Gulch, Sanderson Gulch, Weir Gulch, Lakewood Gulch, and Cherry Creek.
There are several municipal and industrial facilities which discharge either directly to or into tributaries of the South Platte River in this reach. The major active discharges into the segment are the Littleton-Englewood wastewater treatment plant (WWTP), the Glendale WWTP,the City Ice Company, two Public Service company power plants (Zuni and Arapahoe), and Gates Rubber.
The South Platte River drainage basin in this area (approximately 120,000 acres) is composed primarily of extensively developed urban area (residential, industrial, commercial, services, roads), parks and recreational areas, gravel mining areas, and rural areas south of the urban centers for farming and grazing.

D-53\ \ \\

Figure 1 SOUTHPLA~'E RIVERWDY AREdMAPln the study area, the South Platte River is typically SO-150 feet wide and 1-16

feet deep (typically l-2 feet) and has anaverage channel bed slope of 12.67 feet per mile, with alternating riffle and pool reaches. The channel banks are composed essentially of sandy-gravelly materials that erode easily when exposed to high-flow conditions. The stream banks are generally sparsely vegetated with trees, shrubs, and grasses (or paving in the urban centers.)
B. Problem Definition
The following use classifications have been designated for Segment 14 of the South Platte River:
O Recreatjon -Class 2-secondary contact O Aquatic Life -Class 1-warm water aquatic life O Agriculture O Domestic Water Supply Following areview of the water quality studies and data available for Segment 14 of the South Platte River, several observations and trends in the data have been noted, including:

0 Fecal collform values exceeded the recommended limits for recreational uses in the lower portlon of Segment 14.

0 Un-ionized ammonia levels exceeded the water quality criterion for the protection of aquatic life in the lower portion of the segment.

0 Levels of total recoverable metals (lead, zinc, cadmium, total iron, total manganese, and total copper) have been measured which exceed the water quality crjteria for the protection of aquatic life. Although the exact points of origin have not been specified, it is generally felt that the source of the ammonia is municipal point sources, and the sources of the metals are industrial point sources.
In addition, the cities of Llttleton and Englewood have challenged the Class I warm water aquatic life use onthe basis that the flow and habitat are unsuitable to warrant the Class I designation, and they have also challenged the apporopriateness of the 0.06 mg/l un-ionized ammonia criteria onthe basis of new toxicity data. The Colorado Water Quality Control Commission in November, 1982 approved the Class I aquatic life classification and the 0.06 mg/l un-ionized ammonia criteria.

c. Approach to UseAttainability
Assessment of Segment 14of the South Platte River was based onasite visit (May 

### 3-4, 1982) which included meetings with representatives of the Colorado Department of Health, EPA(Region VIII and Headquarters) and CampDresser &McKee 

### Inc., and upon information contained in anumber of reports, hearing transcripts and the other related materials. Most of the physical, chemical and biological data was obtained from the USGS, EPA(STORET), DRURP,and from

D-55studies. It was agreed that there was sufficient chemical, physical and

biological data to proceed with the assessment, even though physical data on the aquatic habitat was limited.
II. ANALYSES CONDUCTED
A. Physical Factors
Streamflow in the South Platte River (Segment 14) is affected by several factors including releases from Chatfield Dam, diversions for irrigation and domestic water supply, irrigation return flows, wastewater discharges, tributary inflows, pumping from ground water wells in the river basin, evaporation from once-through cooling at the two power plants in Segment 14, and natural surface water evaporation. Since some of these factors (particularly ground water pumping, evaporation and irrigation diversions) are variable, flow in the South Platte River is used extensively for irrigation and during the irrigation season diversions and return flows may cause major changes in streamflow within relatively short reaches. During the summer, low-water conditions prevail because of increased evaporation, lack of rainfall, and the various uses made of the river water (e.g. irrigation diversions). Municipal, industrial, and storm-water discharqes also contributes to the streamflow in the South Platte River.
Natural pools in the South Platte River are scarce and the shifting nature of the channel bed results in temporary pools, afeature which has atendency to greatly limit the capacity for bottom food production. There are approximately 3-4 pools per river mile with the majority being backwater pools upstream of diversion structures, bridge crossings, low head dams, docking platforms, drop-off structures usually downstream of wastewater treatment plant outfalls, kayak chutes, and debris. The hydraulic effect of each obstruction is generally to cause a backwater condition immediately upstream from the structure, scouring imnediately downstream, and sandhar development below that. These pools act as settling basins for silt and debris which no longer get flushed during the high springs flows once Chatfield Lake was completed.
In the plains, channels of the South Platte River and lower reaches of tributaries cut through deep alluvial gravel and soil deposits. Sparse vegetation does not hold the soils, so stream bank erosion and channel bed degredation is commondurinq periods of high flow, particularly during the spring snowmelt season. The high intensity - low duration rainstorms which occur during the summer (May, June, andJuly) also temporarily muddy the streams.
An evaluation of the physical streambed characteristics of Segment 14 to determine the potential of the Seqment to maintain and attract warmwater aquatic life was conducted by Keeton Fisheries Consultants, Inc. The study concluded that the sediment loads in this reach of the South Platte River could pose a severe problem to the aquatic life forms present, however, further study needs to be conducted to substantiate this conclusion. Furthermore, some gravel mining operations have recently been discontinued thus the sediment problem may have been reduced.
The temperature in the South Platte River is primarily a function of releases from the bottom of Chatfield Lake, the degree of warming that takes place in the shallow mainstream and isolated pools, and the warming that occurs through the mixing of power plant cooling water with the South Platte River.

D-5tJB. Chemical Factors

Water quality conditions in the South Platte River are substantially affected by municipal and industrial wastewater discharges, irrigation return flows and other agricultural activities, and non-point sources of pollution (primarily during rainfall-runoff events). Irrigation and water supply diversions also exert a major influence on water quality by reducing the stream flow, and thereby reducing the dilution assimilative capacity of the river.
O Dissolved oxygen levels were above the 5.0 mg/l criteria acceptable for the maintenance of aquatic life.

0 Average concentrations of un-ionized ammonia exceeded the State water quality criteria of 0.06 mg/l NH3-N only in the lower portion of Segment 14 (north of Speer Rlvd.)
O Average total lead concentrations exceeded the water quality criteria of 25 ug/l in Rig Dry Creek, Cherry Creek, and the South Platte River north of Cherry Creek, ranging from 30-72 ug/l.
O Average total zinc concentrations exceeded the criteria of 11ug/l at all the DRURPsampling stations, ranging from 19-179 ug/l.
O Average total cadmium concentrations exceeded the criteria of 1ug/l in Beer Creek, Cherry Creek and several sites in the South Platte, ranging from 2.2-3.6 ug/l.
O Average total iron concentrations exceeded the criteria of 1,000 ug/l in Cherry Creek and several locations on the South Platte River, ranging from 1129-9820 ug/l.

0 Average soluble manganese concentrations exceeded the criteria of 50 ug/l in the South Platte River north of (and including) 19th Street and in Cherry Creek, ranqinq from 51-166 ug/l.
' Average total copper concentrations equalled or exceeded the criteria of 25 ug/l at all but two of the DRURPsamplinq sites, ranging from 25-83

ug/l l 

# c. Biological Factors
Several electrofishing studies have been conducted on the South Platte River in recent years. Most of the sampling took place in the fall with the exception of the study in the spring (1979). The data was reviewed by Colorado Department of Health personnel and it was generally agreed that the overall health of the existing warm water fishery is restricted by temperature extremes (very cold and shallow during the winter and low flow and high temperatures during the summer),

lJ-57the lack of sufficient physical habitat (i.e.

rocks and dams, structures for cover including

and deep pools) and the potentially stressful conditions created bythe wastewater discharges (i.e. silt and organic and inorganic enrichment). Following a review of the physical, chemical, and biological data available on the South Platte River, it was concluded that a fair warm water fishery could exist with only modest habitat improvements and maintenance of the existing ambient water quality and strict regulation prevent overfishing. habitat and water quality improvements, With large brown trout could potentially become a part of the fishery in Segment 14of the South Platte River.
III. FINDINGS
A. Existing Uses Segment 14 of the South Platte River is currently being used in the following ways: O Irrigation Diversions and Return Flows ' Municipal and Industrial Water Supply ' Ground Water Recharge O Once-through Cooling ' Municipal, Industrial, and Stormater Oischarges O Recreation ' WarmWater Fishery
The irrigation diversions, water supply, ground water recharge, and cooling uses have primarily affected the flow in the South Platte River, resulting in significant dewatering at times. Irrigation return flows and wastewater dishcharges, on the other hand, exert their effects on the ambient and storm water quality in the River. These previous uses ultimately affect the existing warm water fishery and how the public perceives the river for recreation purposes.
R. Potential I)ses
With the exception of apotential for increased recreation and the improvement of alimited warmwater fishery, it is anticipated that the existing uses are likely to exist in the future. The increased recreational use will result from future Platte River Greenway Foundation projects. The improvement of a limited warm water fishery maycome about in the future as the result of habitat improvements (Pools, cover) control of toxic materials (un-ionized ammonia, heavy metals, cynanide), and the prevention of extensive sedimentation. However, the success of the fishery would rely onstrict fishery regulations to prevent overfishing.

D-58

### IV. SUMMARYANDCONCLIISIONS

Asummary of the findinqs from the use 3ttainahilit.y analysis are listed below:

0 There is evidence to indicate that awarm water aquatic life community does exist and the potential for an improved fishery could be attained with slight habitat modifications (i.e. cover, pool).
' Elevated un-ionized ammonia levels were exhibited in the lower portion of Segment 14, although this cannot beattributed to the Littleton-Englewood WWTPdischarge upstream. However, at the present time there is nn basis for achange in the existing un-ionized ammonia criterion, particularly if EPA's methodology for determining site specific criteria becomes widely accepted.

0 Increased turbidity exists in the South Platte River during a good portion of the fish spawning season, which represents a potential for problems associated with fish spawning.

0 Increased sedimentation and siltation in the South Platte River could pose a potential threat to the aquatic life present; however, this condition might be reduced if Chatfield Lake could beoperated to provide periodic flushing of the river.

0 Elevated levels of heavy metals were ohserved in water and sediment samples, which could potentially affect the existing aquatic life.

0 Insufficient data existed to determine the possible effects of chlorine and cyanide onthe aquatic life present.

0 Fecal coliform levels were extremely high in the lower portion of the South Platte River and Cherry Creek during periods of both low and high flow. The source in the South Platte River is apparently Cherry Creek, but the origin in Cherry Creek is unknown at this time.
On the basis of the preceding conclusions and recommendations, the warmwater fishery use classification and the un-ionized ammonia criterion (0.06 mg/l) recommended for Segment 14 of the South Platte should remain unchanged until there is further evidence to support making those changes.

u-59