Presentation on theme: "Truckee River Water Quality: Current Conditions and Trends Relevant to TMDLs and WLAs Prepared for: Truckee Meadows Water Reclamation Facility. City of."— Presentation transcript:
Truckee River Water Quality: Current Conditions and Trends Relevant to TMDLs and WLAs Prepared for: Truckee Meadows Water Reclamation Facility. City of Reno and City of Sparks, Nevada Prepared by: Alan Jassby PhD, Ted Daum MS, and Charles Goldman PhD, Ecological Research Associates, Davis, CA.
Truckee River Info Gateway (TRIG) www.truckeeriverinfo.org City of RenoCity of Reno –Mahmood Azad, Program Manager City of SparksCity of Sparks –Mike Brisbin, WQ Coordinator, TMWRF Ecological Research AssociatesEcological Research Associates –Dr. Charles Goldman –Dr. Alan Jassby –Ted Daum (currently at EDAW, Inc.) UC DavisUC Davis –David Waetjen
Study Goals Provide a description of the conditions and trends for TMDL water quality constituents Estimate loads of these constituents at key points in the Truckee River Relative impact of TMWRF effluent compared with other sources
Regulatory Background Clean Water Act –The Clean Water Act of 1972 (CWA) is the primary federal law that governs and authorizes water quality control activities by the EPA as well as the states. –The law requires point-source effluent limits for industry and publicly owned treatment works (POTWs) and water quality standards for contaminants in surface waters.
Regulatory Background Section 303(d) Impaired Waters List –Total Maximum Daily Load (TMDL) –Waste Load Allocation (WLA) Nevada Division of Environmental Protection (NDEP) Bureau of Water Quality Planning water quality protection functions including: –developing water quality standards for surface waters, contained in the Nevada Administrative Code (NAC)
Total Maximum Daily Load (TMDL) amount of loading that the water body can receive and still meet water quality standards can also act as a plan to reduce loading of a specific pollutant from various sources to achieve compliance with water quality objectives Waste Load Allocations (WLA) - must include an allocation of allowable loadings to point and non-point sources, with consideration of background loadings and a margin of safety.
Data Sources Most data used in study from Truckee Meadows Water Reclamation Facility (TMWRF) monitoring stations, 1985 – 2006. Names, station codes, locations, and distance (km) from Lake Tahoe.
Median Ratio of Daily TMWRF Loads to TMWRF + mccarran + steamboat + ntd in Summers of 1998 – 2006.
Conclusions N Loadings Above Lockwood: Truckee River > Steamboat Creek > TMWRF > North Truckee Drain No trends in loading of any N fraction since WLAs adopted despite increase in service area population, likely due to TMWRF N treatment advances Strong N limitation for plant growth, especially downstream
Conclusions TN and TP loadings between wadsworth and nixon, and between lockwood and clark, exceed TMWRF effluent contributions TP and DRP loadings from TMWRF have increased since 1995. Increase similar to population increase. TP and DRP loadings have also increased upstream of TMWRF and in North Truckee Drain
Conclusions Map lower watershed areas for potential N and P sources, synoptic study to compare contributions TMDL and WLA revisions should take into account relevant timescales –Integrated loading for Pyramid Lake impacts –Median daily loading during summer for nutrient loading to the Truckee River
TRIG and ERA Truckee River Water Quality Report TRIG Potential –Loading Calculations –TMDLs and WLAs –Contaminant Status and Trends –Data Gaps –Other