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0 Volume III - Comments and Responses FEIS - Navajo Reservoir Operations The data gathered from the Summer and Winter Flow Tests constitute a small portion of the overall resource impact analysis. Specialists from State agencies and Tribes/Nations were consulted regarding the long-term impacts of low flows on various resources. When it was not possible to fully measure impacts, models (such as those relating to hydrology and physical habitat [trout] simulation) were developed to estimate impacts from both Navajo Reservoir fluctuations and downstream flow changes. General Comment 23: With the lower minimum release, lowered dilution of pollutants • in the river will make it increasingly difficult to comply with Clean Water Act discharge permits, such as permits for municipal sewage treatment plants (e.g., Bloomfield's). This is particularly true because of EPA's move towards permitted discharge levels based on Total Maximum Daily Loads (TMDL). The DEIS needs more information on water quality impacts and the effects on people, including the effects on their water supply. Increased concentration of fecal coliforms and - other pollutants would cause health and other problems. Is mitigation proposed for water - quality impacts? Pollutants in agricultural runoff and also heavy metal and selenium pollutants will cause problems at lower flows. Fish and wildlife will be affected by water li qua ty exceedences. - Response: In general, reoperation of Navajo Reservoir would affect water quality by either the addition or reduction of high-quality reservoir water released to the river. When l re eases are lowered, the river has less ability to dilute pollutants. Water quality concerns • are related to these low releases. For a more detailed water quality assessment of the Basin, refer to the water quality assessments and resource reports written for the ALP Project, SJRBRIP, and NIIP. These - projects have included studies of the San Juan River water quality and the impacts to the • San Juan River in detail. In addition, the U.S. Geological Survey (GS) has completed several reports on the water quality conditions in the Basin. s - At the present time, water releases from dams are not regulated as pollution point sources. - Under the Clean Water Act, the State of New Mexico assesses water quality within the State every 2 years and reports it to the EPA (this document is commonly referred to as a Section 305(b) report). This report includes the degree of use support, causes (pollutants - and other stressors), and sources of impairment. If a reach of river is impaired, then it is - placed on the State's list of water quality-limited waters requiring TMDL, commonly referred to as the Section 303(d) list. For the San Juan River, several reaches are on the Section 303(d) list, and the State is in the process of evaluating these reaches as well as the - entire Basin within New Mexico. Reclamation has supplied the State with its sample results as well as other water quality documents. If reaches are found to be impaired and TMDL are determined, sources of