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Nevada began its Bioassessment Program in the year 2000 and has continued to collect biological information on an annual basis. Although the program is in its infancy, the State is planning to continue collecting biological data for ambient  monitoring and to assist in defining reference conditions and sites.
There are 7 primary water basins in Nevada and that State has collected biological data annually on 4 of these basins covering approximately 650 surface stream miles. It is expected the State will continue to collect at these river basins, in addition to new basins and several lakes, until a valid biological baseline has been established. It is expected to take approximately 4-5 years for the baseline to be established. After such time, the State is expected to switch to an alternate site or basin ambient bioassessment monitoring program.
Nevada's Bioassessment Sites
The program primarily consists of collections of macroinvertebrates, physical habitat evaluations, and physical measurement of slope, velocity, flow, dissolved oxygen, specific conductivity, pH, tempera Periphyton, plankton, and/or chlorophyll sampling is conducted when necessary to assist in defining problem areas.
Water chemistry data is collected at sites where the water chemistry is currently unknown. The data will eventually be used in 305(b) and 303(d) reports in addition to basin assessments to assess stream health. Some NPDES dischargers in the State are voluntarily collecting macroinvertebrates to assess impact to the aquatic environment.
Reference site criteria are currently being defined based on available information. The State expects to use chemical data, habitat assessments, physical measurements, professional knowledge and degrees of human impact to define the conditions and sites. Where reference sites are unavailable, the State expects to use modeling; metrics and/or least/minimally disturbed sites to evaluate conditions. It is anticipated to take several years for reference sites to be selected.
An independent biological laboratory conducts identification of macroinvertebrates. QA/QC of macroinvertebrate identification consists of approximately 15% of the samples to be analyzed by two distinct biological laboratories. Data collected will be stored annually in the Ecological Data Application System(EDAS>. Analysis and  evaluation of the bioassessment data will be developed as the program progresses and based on the most accurate methods. Reference sites, where appropriate, will be sued as a baseline for analysis.
Nevada recently hosted its first bioassessment conference in Reno, NV. The conference resulted in the formation of a State Bioassessment Committee consisting of State agencies, tribes, and industry. The primary goal of the committee is to evaluate and coordinate protocols, methodologies, and sampling in the State. Nevada also participates in the National Aquatic Life Use (ALUS) work group based out of EPA headquarters in Washington, D.C. The State is also planning to host an Arid West Aquatic Life Use Workgroup in conjunction with other arid states, tribal entities and EPA in the next year
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