Water Quality

Thanks to high-quality water sources, skilled staff, and efficient water treatment facilities, Truckee Meadows Water Authority (TMWA) provides some of the best quality water in the nation. We go to great lengths to ensure your tap water is safe, clean and reliable.

For information on the Environmental Protection Agency’s per- and poly- fluoroalkyl substances (PFAS) rule, click here https://tmwa.com/pfas

For information on the Environmental Protection Agency’s lead and copper rules, click here https://tmwa.com/lcr

To help you more fully understand the quality of the water we provide, we have provided the resources below. Should you have additional questions, please call TMWA's Water Quality Department at (775) 834-8118.

Our annual Water Quality Report is provided to our customers in accordance with the Safe Drinking Water Act, has been compiled to help you understand the water supply and quality issues vital to our area.

Image of TMWA 2026 Water Quality Reports

Click Here to View the Water Quality Report for Your Location

Drinking Water Standards

Below is a list of drinking water constituents TMWA regularly monitors as required by local, state, and federal agencies. If any of the constituents are detected throughout the TMWA distribution system, it is reported in our Water Quality Report which is published annually.

Water treated by TMWA meets all U.S. Environmental Protection Agency (EPA), Nevada Division of Environmental Protection, and Washoe County Health District water quality standards. In most cases, our water is significantly better than these standards require. TMWA’s professional staff of engineers, chemists, microbiologists and operators continually monitors our water quality. More than 1,000 laboratory tests are performed each month on over 180 samples taken from various locations within the TMWA distribution system. Testing is performed both at the treatment plants and throughout the distribution system to make sure high-quality water is delivered to our customers.

MCL or maximum contaminant level is the highest level of a constituent that is allowed in drinking water.
ConstituentMCL (mg/L or ppm)
pH6.5 - 8.5 (pH units)
Magnesium150
Nitrite (as N)1
Nitrate (as N)10
Total Dissolved Solids (TDS)1000
Fluoride4 (primary), 2 (seconary)
Chloride400
Sulfate500
Asbestos7 (MFL longer than 10 um)
Color15.0 (CU)
Cyanide0.2
MBAS0.5
Odor3.0 (TON)

Metals

Mercury0.002
Beryllium0.004
Aluminum0.2
Chromium0.1
Manganese0.1
NickelN/A
Copper1.3 (primary), 1 (secondary)
Zinc5
Arsenic0.010
Selenium0.05
Silver0.10
Cadmium0.005
Antimony0.006
Barium2
Thallium0.002
Lead0.015
Iron0.6
SodiumN/A

Volatile Organic Compounds

Vinyl Chloride0.002
Benzene0.005
Carbon Tetrachloride0.005
1,2-Dichloroethane0.005
Trichloroethylene0.005
1,4-Dichlorobenzene0.075
1,1-Dichloroethylene0.007
1,1,1-Trichloroethane0.2
cis-1,2-Dichloroethylene0.07
1,2-Dichloropropane0.005
Ethylbenzene0.7
Chlorobenzene0.1
1,2-Dichlorobenzene0.6
Styrene0.1
Tetrachloroethylene0.005
Toluene1
trans-1,2-Dichloroethylene0.1
Xylenes10
Dichloromethane0.005
1,2,4-Trichlorobenzene0.07
1,1,2-Trichloroethane0.005

Carbamates and Urea Pesticides

Carbofuran0.04
Oxamyl0.2

Chlorinated Acids Herbicide

2,4,5-TP (Silvex)0.05
2,4-D0.07
Dalapon0.2
Dinoseb0.007
Pentachlorophenol0.001
Picloram0.5

Chlorinated Pesticides and/or PCBs

Chlordane (tech)0.002
Endrin0.002
gamma-BHC (Lindane)0.0002
Heptachlor0.0004
Heptachlor epoxide0.0002
Hexachlorobenzene0.001
Hexachlorocyclopentadiene0.05
Methoxychlor0.04
PCBs, Total0.0005
Toxaphene0.003

Diquat and Paraquat

Diquat0.02

Endothall

Endothall0.1

Fumigants

1,2-Dibromo-3-chloropropane0.0002
1,2-Dibromoethane (EDB)0.00005

Glyphosate

Glyphosate0.7

SOCs

Alachlor0.002
Atrazine0.003
Benzo (a) pyrene0.0002
Bis(2-ethylhexyl)adipate0.4
Bis(2-ethylhexyl)phthalate0.006
Simazine0.004
SOCs
Dioxin3.E-08

Rads

Uranium0.03
Gross BetaAnnual dose equivalent to the human body or any internal organ may not exceed 4 mrem/yr.
Radium 2265 (pCi/L)
Radium 2285 (pCi/L)
Gross Alpha15 (pCi/L)

Water Quality - Frequently Asked Questions