Water Quality Report for City of Tumwater Water System
The City of Tumwater's annual Drinking Water Quality report details water quality sampling results collected during the previous five years. The dedicated City staff who operate and maintain the water system continually strive to ensure that the water delivered to your tap is of the highest quality possible.
All of Tumwater's drinking water comes from groundwater sources. To access this groundwater, the City operates eleven wells in three different well fields. The Palermo wellfield is located in the Deschutes River valley; the Bush wellfield is located near George Washington Bush Middle School; and the Port wellfield is located in the vicinity of City Hall. Since all three sites are in different locations, they require slightly different processes to create clean drinking water. Water taken from the Bush and Palermo wellfields are aerated for corrosion control and to eliminate the potential for volatile organic compound (VOC) contamination. Chlorine is added to all sources to control naturally occurring bacteria. In addition, the Tumwater system has two interconnections with the City of Olympia's water system and with the Lakeland Manor water systems. These two interconnections serve as supplementals to the drinking water supply in the event of an emergency. The City of Tumwater also maintains an emergency back-up source at the Tumwater Valley Municipal Golf Course.
What we look for in your water
Drinking water flows across the land and through the ground before being pumped into the drinking water distribution system. As the water moves through the ground it dissolves naturally occurring minerals, and can pick up additional substances due to the presence of animal or human activities. The City tests for the following contaminants at regular intervals to ensure that drinking water is clean and safe:
Microbial contaminants, such as viruses, parasites, and bacteria that may come from sewage treatment plants, septic systems, agricultural livestock operations, or wildlife.
Inorganic contaminants, such as salts and metals, which can occur naturally or result from urban stormwater runoff, industrial or domestic wastewater discharges, oil and gas production, mining, or farming.
Pesticides and herbicides, which may come from various sources such as agriculture, urban stormwater runoff, and residential uses.
Organic chemical contaminants, including synthetic and volatile organic chemicals, which are by-products of industrial processes and petroleum production. They can also come from gas stations, urban stormwater runoff, and septic systems.
Radioactive contaminants, which can occur naturally or result from oil and gas production and mining activities.
For information about how the City protects your groundwater and to see our most recent Wellhead Protection Plan visit our wellhead protection page.
Water Quality Results from 2014 - 2019
Source Water Sampling: The following three tables detail water quality results from samples collected at the City's wells.
|Primary drinking water standards regulated by EPA to protect public health|
|Contaminant||Units||Highest level allowed (MCL)||Goal not to exceed (MCLG)||Amount present in your water||Year detected||Source|
|Nitrate||ppm||10.00||10.00||1.480||ND - 1.480||2019||Naturally-occurring, found in groundwater, typically from agricultural runoff|
|Barium||ppm||2.000||20.000||0.005||0.002- 0.005||2019||Erosion of natural deposits|
|Arsenic||ppm||0.010||0.000||0.001||NA-0.001||2019||Erosion of natural deposits; runoff from waste|
|Gross Beta||pCi/L||4.000 mrem/yr||NA||2.730||NA-2.730||2015||Decay of naturally radioactive deposits and/or man-made radioactive materials.|
|Radium 228||pCi/L||5||NA||2.780||NA-2.780||2015||Decay of naturally radioactive deposits and/or man-made radioactive materials.|
|Secondary drinking water standards regulated by EPA for aesthetics (taste, color, etc.)|
|Contaminant||Units||Goal not to exceed (SMCL)||Amount present in your water||Year detected||Source|
|Total Dissolved Solids||ppm||500.0||129.0||100.0-129.0||2019||Naturally-occurring|
|Additional monitoring required by the State of Washington|
|Contaminant||Units||Goal not to exceed||Amount Present in Your Water||Year detected||Source|
Distribution System Sampling: The following table details water quality results from samples collected in the city's distribution system pipes.
|Primary drinking water standards regulated by EPA to protect public health|
|Contaminant||Units||Highest level allowed (MCL accept where indicated)||Goal not to exceed (MCLG accept where indicated)||Amount present in your water||Year detected||Source|
|Chlorine residual||4.000 (MRDL)||4.000 (MRDL)||0..650||0.200-0.650||2019||Water additive used to control bacteria|
|Haloacetic Acids (HAA5)||ppm||0.060||NA||0.006||0001-0.006||2019||Byproduct of drinking water disinfection|
|Total Trihalomethanes (TTHM)||ppm||0.080||NA||0.005||ND-0.005||2019||Byproduct of drinking water disinfection|
Tap Sampling: The following table details water quality results from samples collected at our customer's taps.
|Primary drinking water standards regulated by the EPA to protect public health|
|Contaminant||Units||Action level||Goal not to exceed (MCLG)||2019 results*||Homes exceeding the action level||Source|
|Copper||ppm||1.300||1.300||0.212||ND-0.212||Corrosion of household plumbing, 0 out of 60 samples.|
|Lead||ppm||0.015||0.000||0.000||ND-0.000||Corrosion of household plumbing, 1 out of 60 samples|
90th Percentile: 90 percent of the samples were less than the values shown.
Action Level: The concentration of a contaminant which, if exceeded, triggers treatment or other requirements which a water system must follow.
Aeration: Drinking water treatment that uses air to dissolve gases or volatile compounds and raise the pH of drinking water.
Contaminant: Contaminants, as seen in this table, are not all "bad". Contaminants are anything found in your water other than hydrogen and oxygen, which make up water, and can be both healthy and unhealthy, depending on the particular substance and quantity.
Distribution System: Water supply network that delivers potable water from a treatment plant or wells to water consumers.
EPA: United States Environmental Protection Agency.
Maximum Contaminant Level (MCL): The highest level of a contaminant that is allowed in drinking water. MCLs are set as close to the MCLGs as feasible using the best available treatment technology.
Maximum Contaminant Level Goal (MCLG): The level of a contaminant in your drinking water is below the Maximum Contaminant Level Goal (MCLG) number indicated, then there is no know or expected risk to your health.
Maximum Residual Disinfectant Level (MRDL): The highest level of a disinfectant allowed in drinking water. There is convincing evidence that the 2addition of a disinfectant is necessary for control of microbial contaminants.
Maximum Residual Disinfectant Level Goal (MRDLG): The level of a drinking water disinfectant below which there is no known or expected risk to health. MRDLGs do not reflect the benefits of the use of disinfectants to control microbial contaminants.
NA: Not Applicable. There is no unit of measurement, only absence or presence of.
ND: Not Detected. The contaminant was not detected during sampling events.
NTU: Nephelometric Turbidity Unit
ppm: one part per million = 1 mg/L
Secondary Maximum Contaminant Level (SMCL): Non-enforceable guidelines regarding chemicals that may cause cosmetic or aesthetic effects in drinking water. EPA recommends these secondary standards but does not require water-supply systems to comply.
TT: Treatment Technique: Enforceable procedure or level of technological performance which public water systems must follow to ensure control of a contaminant.
Additional water quality information
The frequency that we sample our sources is determined by the Washington State Department of Health (DOH). DOH has determined that the level of risk in our system is low for certain contaminants, and granted the City waivers to sample less frequently. The table below describes the sampling frequency for our sources and where waivers have been given.
|Contaminant or Contaminant Group||Source||Sampling Frequency|
|Pesticides||All||Every 3 years*|
|Soil Fumigants||All||Every 3 years*|
|Complete Inorganic (IOC)||All||Every 9 years*|
|Herbicides||All||Every 9 years*|
|Volatile Organic Compounds (VOC)||Palermo well field||Every 3 years|
|Wells 9 and 10 (Port well field)||Every 3 years|
|Wells 11 and 15 (Port well field)||Every 6 years*|
|Bush well field||Every 6 years*|
|Gross Alpha and Radium 228||All||Every 6 years|
*Waiver provided by DOH
Drinking water, including bottled water, may reasonably be expected to contain at least small amounts of some contaminants. The presence of contaminants does not necessarily indicate that water poses a health risk. More information about contaminants and potential health effects can be obtained by calling the EPA’s Safe Drinking Water Hotline (1-800-426-4791).
To ensure that tap water is safe to drink, DOH and EPA prescribe regulations that limit the amount of certain contaminants in water provided by public water systems. The Food and Drug Administration (FDA) and the Washington Department of Agriculture regulations establish limits for contaminants in bottled water that must provide the same protection for public health.
Some people may be more vulnerable to contaminants in drinking water than the general population. Immuno-compromised persons, such as persons with cancer undergoing chemotherapy, persons who have undergone organ transplants, people with HIV/AIDS or other immune system disorders, some elderly, and infants can be particularly at risk from infections. These people should seek advice about drinking water from their health care providers. EPA and CDC guidelines on appropriate means to lessen the risk of infection by Cryptosporidium and other microbial contaminants are available from the Safe Drinking Water Hotline 1(800) 426-4791.
In Washington State, lead in drinking water comes primarily from materials and components used in household plumbing. The more time water has been sitting in pipes, the more dissolved metals, such as lead, it may contain. Elevated levels of lead can cause serious health problems, especially in pregnant women and young children. To help reduce potential exposure to lead: Any drinking water tap that has not been used for six hours or more, flush water through the tap until the water is noticeably colder before using for drinking or cooking. You can use the flushed water for watering plants, washing dishes, or general cleaning. Only use water from the cold-water tap for drinking, cooking, and especially for making baby formula. Hot water is likely to contain higher levels of lead. If you are concerned about lead in your water, you may wish to have your water tested. Information on lead in drinking water is available from EPA’s Safe Drinking Water Hotline at
Tier 3 Monitoring Violation: We are required to report the results of your drinking water for total coliform on a regular basis. Results of the regular monitoring are an indicator of whether or not your drinking water meets health standards. During the month of January 2020, we did not report the total coliform results to the state in a timely manner. While we took samples that month, we did not notify the state as quickly as we should have. We submitted them upon becoming aware of the missed deadline. We are no longer in violation and there is nothing you need to do at this time.
Past Water Quality Reports
For more information about groundwater, drinking water and possible contaminants including cryptosporidium and other microbial contaminants, and potential health effects, visit http://www.epa.gov/water, or call the EPA Safe Drinking Water Hotline at