Bear River Basin Water Plan
Final Report

The basin water quality profile provides an inventory of current water quality issues and trends in the basin. Similar to the existing water use profile, surface and ground water quality was assessed in preparation for subsequent sections in the report. Current surface water quality issues serve as a basis for determining whether available surface water is of sufficient quality for future development and use. Current ground water quality is used as an indicator of whether additional ground water can be used to meet future demands.

4.1 Surface Water Quality

Water quality issues within the Bear River basin are monitored by a number of organizations and committees. One of these organizations, the Bear River Basin Water Quality Task Force has been instrumental in the coordination of water quality work within the tri-state (Idaho, Utah, and Wyoming) basin. The Task Force coordinates water quality planning issues with the appropriate regulatory agencies for each state. The primary regulatory agency that manages water quality issues within Wyoming is the Water Quality Division (WQD) of the Wyoming Department of Environmental Quality (DEQ). The WQD developed water quality standard which are documented in Chapter 1, Wyoming Water Quality Rules and Regulations. Chapter 1 is available on the WQD WEB Site at http://soswy.state.wy.us/rules/search.htm. The surface water quality standards are divided based on four surface water classifications:

• Class 1, Outstanding Waters: Class 1 waters are those surface waters in which no further water quality degradation by point source discharges other than from dams will be allowed. Nonpoint sources of pollution shall be controlled through implementation of appropriate best management practices. Water quality and physical and biological integrity which existed on the water at the time of designation will be maintained and protected. The designation of Class 1 waters is reflective of water quality, aesthetic, scenic, recreational, ecological, agricul- tural, botanical, zoological, municipal, industrial, historical, geological, cultural, archaeological, fish and wildlife, the presence of significant quantities of developable water, and other values of present and future benefit to the people.

• Class 2, Fisheries and Drinking Water: Class 2 waters are waters, other than those designated as Class 1, that are known to support fish or drinking water supplies or where those uses are attainable. Class 2 waters may be perennial, intermittent or ephemeral and are protected for the uses indicated in each sub category listed below.

• Class 3, Aquatic Life Other than Fish: Class 3 waters are waters, other than those designated as Class 1, that are intermittent, ephemeral or isolated waters and because of natural habitat conditions, do not support nor have the potential to support fish populations or spawning, or certain perennial waters which lack the natural water quality to support fish (e.g., geothermal areas). Class 3 waters provide support for invertebrates, amphibians, or other flora and fauna which inhabit waters of the state at some stage of their life cycles. Uses designated on Class 3 waters include aquatic life other than fish, recreation, wildlife, industry, agriculture and scenic value. Generally, waters suitable for this classification have wetland characteristics, and such characteristics are a primary indicator used in identifying Class 3 waters.

• Class 4, Agriculture, Industry, Recreation and Wildlife: Class 4 waters are waters, other than those designated as Class 1, where it has been determined that aquatic life uses are not attainable. Uses designated on Class 4 waters include primary contact recreation, wildlife, industry, agriculture, and scenic value.

Figure 22 shows the current stream classifications for the Bear River Basin. Detailed information regarding state, interstate, and federal water quality standards and monitoring are documented in the surface water quality memorandum attached as Appendix N.

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When assessing water quality, it is important that there is a historic record of measurement taken at the same location, representing a range of flow regimes. The USGS has five surface water quality monitoring stations located within the Wyoming portion of the Bear River Basin that have significant historical water quality records. These stations, shown in Table 16 and located on Figure 22, monitor Class 2 stream segments.

Table 16
USGS Surface Water Quality Stations

Gage ID	Stream Name	Period of Record
10020100	Bear River above Reservoir near Woodruff	1985-Present
10027000	Twin Creek at Sage	1975-1981 and 1989-Present
10035000	Smith's Fork at Cokeville	1983-1988, 1989-1992 and 1993-Present
10038000	Bear River below Smith's Fork	1992-Present
10039500	Bear River at Border	1965-1989

Although levels of potassium, nitrogen, and sediment are of specific concern to downstream interests at Bear Lake, only sporadic measurements are available in the Bear River Basin in Wyoming. Therefore, it is difficult to determine if water flowing from Wyoming is contributing to the levels downstream. However, Total Dissolved Solids (TDS), a measure of the total amount of dissolved salts in water, is easily measured and is frequently used as an indicator of overall water quality. TDS has been measured over a relatively long period of time with some consistency at the five USGS water quality stations shown in Table 16. TDS measurements at the gaged locations were analyzed to determine:

1. The compliance with Safe Drinking Water Act standards
2. The relationship between TDS and streamflow
3. The variations in TDS from upstream to downstream gages
4. The variations in TDS over time

Table 17 shows the Wyoming Water Quality Rules and Regulations TDS standards for domestic, agricultural, and livestock use.

Table 17
TDS Standards

Pollutant	Domestic	Agricultural	Livestock
Total Dissolved Solids	500 mg/L	2000 mg/L	5000 mg/L

4.1.1 Compliance with Standards

Measurements at the five USGS gages were reviewed to determine if they were in compliance with the TDS standards. The following summarizes the review:

• The USGS gage on the Bear River above Woodruff Narrows Reservoir measured TDS of less than 500 mg/L for each of the 59 recorded measurements.

• The USGS gages on Smith's Fork measured TDS of less than 500 mg/L for each of the 29 recorded measurements.

• The USGS gages on the Bear River below Smith's Fork measured TDS of less than 500 mg/L for each of the 24 recorded measurements.

• The USGS gages on the Bear River at Border, Wyoming measured TDS of less than 500 mg/L for all but four of the 272 recorded measurements. The four measurements exceeded the 500 mg/L standard for domestic use but were well within the 2,000 mg/L standard for agricultural use. In fact, no measurement at that site exceeded 600 mg/L.

• The USGS gage on Twin Creek measured TDS between 500 and 1000 mg/L in around 50 percent of the 190 recorded measurements. Two measurements, or around 1 percent of the total measurements, exceeded 1000 mg/L.

Surface water in the Bear River and Smith's Fork is of sufficient quality for domestic use. Surface water in Twin Creek is of sufficient quality for livestock and agricultural use, which is the primary use on Twin Creek. Because Twin Creek had the highest concentration of TDS in the basin, the other measured water quality parameters on Twin Creek (dissolved manganese and total nitrogen) were also reviewed. This review showed that both dissolved manganese and total nitrogen are within the acceptable range set by the Safe Drinking Water Act.

4.1.2 Relationship between TDS and Streamflow

Figure 23 shows the relationship between TDS and Streamflow at the USGS gage above Woodruff Narrows Reservoir. As shown, TDS decreases with an increase in flow. This expected trend can be attributed to the source of water during different flow regimes. In the late spring and early summer, much of the flow is direct runoff from snow melt. In the late summer and non-irrigation months, a greater percent of the total flow is from agricultural and municipal return flows. Note that agricultural return flows are lagged over a four month period and these return flows are generally higher in TDS due to both human influence and naturally occurring constituents in the soil. Each of the five USGS gage sites show this general trend. As expected, the measurements also show that TDS is higher during dry years.

Figure 23
USGS Gage - Bear River above Reservoir, near Woodruff, UT

4.1.3 Variation in TDS from Upstream to Downstream Gages

Figure 24 shows the average TDS for the available data from the Bear River above (Woodruff Narrows) Reservoir downstream to the Bear River below Smith's Fork and the Bear River at Border. As shown, the TDS increases from upstream to downstream, reflecting the use, return, and reuse of the limited resource. Twin Creek enters the Bear River between Woodruff Narrows Reservoir and Smith's Fork, which also may contribute to the increase in TDS in that reach. The reach from the Bear River below Smith's Fork to Border has little development, reflected in the TDS concentrations which remain relatively constant between the two gages.

Figure 24
Average Total Dissolved Solids along
Bear River from Upstream to Downstream

4.1.4 Variation in TDS Over Time

Figure 25 shows the amount of TDS measured at the Bear River at Border gage from 1961 through 1989. The TDS has been relatively constant over the available period. The other four gages also show that TDS has not increased over the period of records.

Figure 25
TDS at Bear River at Border, WY - 1961 through 1989

4.1.5 Total Maximum Daily Loads / 303(d) List

Total Maximum Daily Loads (TMDLs) are the amounts of pollutants a waterbody can receive and still maintain its designated uses. TMDLs are required to be established for each pollutant that is contributing to the impairment of a waterbody. Development of TMDLs must consider both point source and non-point source pollution and additionally must account for natural background conditions.

Section 303(d) of the Clean Water Act requires States to:

• Identify all the waters in the State which are impaired (water which cannot meet its designated use)

• Prioritize all impaired waters for the development of TMDLs based on public health and environmental risk

• Establish and adopt TMDLs for all impaired waters or for all waters that would be impaired if a TMDL was not established

Bridger Creek is currently the only stream segment in the basin that is on the 303(d) list. The impairment on Bridger Creek was indicated as physical degradation due to non- point source pollution causing potential impairment of aquatic life use support, and was listed as a low priority for developing TMDLs. Two stream segments within the Bear River Basin were delisted from the 1998 303(d) list; Yellow Creek below the Evanston Waste Water Treatment Plant, and the Bear River below the Cokeville Waste Water Treatment. These waterbodies were delisted due to the implementation of ammonia, fecal coliform and total residual chlorine TMDLs for Yellow Creek, and the implementation of fecal coliform and total residual chlorine TMDLs for the Bear River.

Wyoming DEQ is working closely with their counterparts in Utah and Idaho to establish appropriate TMDL standards in the basin. At the time of this report, the process is still on-going.

4.1.6 Surface Water Quality Summary

The following summarizes the surface water quality in the Bear River Basin:

• The primary use of water in this basin is for agricultural purposes, and when the data available for TDS and other parameters are compared to standards set for agricultural use, concentrations are consistently below the water quality limits.

• With the exception of Twin Creek, all the gages have TDS concentrations consistently below the TDS standards set for drinking water limits.

• Concentrations of TDS vary with flow. During low flow seasons, such as late summer months and non-irrigation seasons, the concentration of TDS increases, likely due to agricultural and municipal return flows. During high flow seasons, such as late spring and early summer months, TDS concentrations decrease.

• Throughout the study period for the USGS water quality gages, no significant increase has been seen in TDS concentrations.

• Only Bridger Creek is currently on the 303(d) list, but is identified as a low priority for developing TMDLs.

• Wyoming DEQ is currently working closely with their counterparts in Utah and Idaho to establish appropriate TMDL standards in the basin.

4.2 Ground Water Quality

Ground water quality data were obtained from the U.S. Geological Survey's Water Quality database, as discussed in Appendix O. A GIS coverage was developed from this database that provides a spatial reference for over 24 water quality parameters from 57 wells and 49 springs. Because of limited data for most parameters, only Total Dissolved Solids (TDS) is discussed in more detail.

As discussed in the Surface Water Quality Section, TDS is a measure of the dissolved solid mineral content and is a general indicator of the suitability of water for various uses. The U.S. EPA and the Wyoming Ground Water Standard for TDS in public water systems is 500 mg/L. The Wyoming Ground Water Standard for agricultural use is 2000 mg/L and for livestock use is 5000 mg/L. Table 18 lists the U.S. Environmental Protection Agency (EPA) recommended guidelines for TDS in irrigation water and its effects on crops.

Table 18
EPA Recommended Guidelines for TDS in Irrigation Water

TDS Concentration (mg/L)	Guidelines
<500	Water for which no detrimental affects are usually noticed.
500 – 1000	Water that can have detrimental affects on sensitive crops.
1000 – 2000	Water that can have adverse affects on many crops; requires careful management practices.
2000 – 5000	Water that can be used for tolerant plants on permeable soils with careful management practices.

Figure 26 shows the location of wells with TDS measurements, and the corresponding TDS values, from the USGS database. As shown, most of the wells are in the alluvial aquifer. With the exception of the Twin Creek area, most of the TDS measurements are from the alluvial aquifer. Some TDS amounts were obtained from water conductivity measurements. TDS concentrations from thirty-three alluvial wells ranged from 190 to 1,030 mg/L as follows:

• 12 out of 33 (36 %) alluvial aquifer wells exceed the domestic standard (500 mg/L); and

• 3 out of 33 (9 %) alluvial aquifer wells exceed the agricultural standard (2,000 mg/L).

TDS concentrations from 59 bedrock aquifer wells and springs range from 54 to 5,403 mg/L as follows:

• 26 out of 59 (44 %) bedrock aquifer wells exceed the domestic standard (500 mg/L); and

• 8 out of 59 (14 %) bedrock aquifer wells and springs exceed the agricultural standard (2,000 mg/L).

Because these measurements represent 17 different bedrock formations, any generalization concerning specific bedrock aquifer quality is speculative. Measurements in individual formations are discussed in the memorandum attached as Appendix O.

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Figure 26 highlights the TDS concentrations from wells and springs. This figure shows that TDS concentrations increase from south to north in the alluvial aquifer. This is likely a result of high TDS bedrock spring discharge in the Twin Creek Area and increased agricultural and municipal return flows. As shown, measured TDS in the alluvial aquifer rarely exceeds the 1,000 mg/L standard for agricultural use.

4.2.1 Ground Water Quality Summary

Unlike continuous surface water quality gages, ground water quality measurements in the Bear River Basin have generally not been taken at the same location over time. Therefore, it is difficult to make assessments regarding trends in water quality. In addition, the number of measurements from individual bedrock formations are limited, and it is recognized that each formation is unique. However, generally conclusions can be made regarding the alluvial aquifer ground water quality:

• Water quality is generally good, but may exceed domestic standards in some areas

• Water quality usually meets agricultural and livestock standards

• Water quality is generally better in the southern (upstream) portion of the basin