Drinking Water Quality Data
At the end of each month, the Water Treatment Plant staff run reports on the Water Quality Data averages for the previous month. The data is then posted here.
February 2025
Raw Water Quality
- Non-Carbonate Hardness, ppm: 103
- Total Hardness, ppm: 400
- Total Hardness, grains per gallon: 23.37
- pH: 7.36
Treated Water Quality
- Non-Carbonate Hardness, ppm: 105
- Total Hardness, ppm: 155
- Total Hardness, grains per gallon: 9.05
- pH: 9.51
- Chlorine residual, ppm: 2.83
- Iron content, ppm: 0.01
- Fluoride content, ppm: 0.27
Bacterial Samples
- Samples Taken: 61
- Confirmed Positive Samples: 0
Water Plant and Laboratory Services staff analyze many water supply parameters at various times. Some parameters are tested daily, some annually, and some only once every nine years.
Click here to examine all the monthly drinking water parameters.(PDF, 85KB)
The following is further explanatory information regarding water supply analysis and reporting:
National Primary Drinking Water Regulations (NPDWR) are legally enforceable primary standards and treatment techniques that apply to public water systems. The NPDWR protects public health by limiting the levels of contaminants in drinking water. It covers Microorganisms, Disinfectants, Disinfection By-products, Inorganic Chemicals, Organic Chemicals, Selected Per-and Poly-fluoroalkyl Substances (PFAS), and Radionuclides. Click here for more information on National Primary Drinking Water Regulations.
Microbiological standards allow no more than 5.0% of all samples to test total coliform-positive in a month. For water systems that collect fewer than 40 routine samples per month, no more than one sample can be total coliform-positive per month. Every sample that tests positive for total coliform must be analyzed for either fecal coliforms or E. coli. If two consecutive total coliform-positive samples are detected and at least one is also positive for E. coli or fecal coliforms, the system has an acute MCL violation. Click here for the reference guide.
Lead and copper are regulated by a Treatment Technique that requires systems to control the corrosiveness of their water. If more than 10% of tap water samples exceed the action level, water systems must take additional steps. For copper, the action level is 1.3 mg/L, and for lead is 15 ug/L. Click here for the EPA's Lead and Copper Rule.
National Secondary Drinking Water Regulations (NSDWRs or secondary standards) are non-enforceable guidelines regulating contaminants that may cause cosmetic effects (such as skin or tooth discoloration) or aesthetic effects (such as taste, odor, or color) in drinking water. EPA recommends secondary standards to water systems but does not require systems to comply. Click here for the National Secondary Drinking Water Regulations.
The City of Ames has proactively undertaken a sampling initiative looking at our finished drinking water and our inventory of 22 wells to determine the prevalence of a class of chemicals known as per-and polyfluoroalkyl substances, commonly referred to by the acronym “PFAS.” This is a huge class of manmade compounds that includes more than 12,000 individual chemicals. Click here for more information on PFAS testing in Ames.
Ames Water and Pollution Control Department's Statement on Nitrate:
There have been many news media reports recently regarding nitrate in drinking water. This has prompted questions about the presence of nitrate in Ames water. The Ames Water Plant uses 22 groundwater wells as its water source. These wells are regularly tested for nitrate, and the results are reported to the Iowa Department of Natural Resources. Water is tested each winter as it enters the Water Plant for treatment. Each spring, all 22 wells are tested individually. The maximum contaminant level for nitrate is 10 milligrams per liter. In all cases, Ames water has tested less than the detection limit for nitrate, which is only 1 milligram per liter. The City is fortunate to have a safe supply of drinking water, free from the presence of nitrate that some water utilities are currently dealing with. For more information on City of Ames water, please refer to our annual consumer confidence report. A link for this report can be found here.