2025

Water Quality Report for City of Chelsea

Once again, the City of Chelsea Water Department is pleased to submit the drinking water quality report for the 2025 calendar year.  This information is a snapshot of the quality of the water that we provided to you in 2025.  Included are details about where your water comes from, what it contains, and how it compares to Environmental Protection Agency (EPA) and state standards.

At present your tap water comes from three wells. Well #5, well #6 and well #7 are approximately 60 feet deep. The oldest of the three wells, well number 5 was drilled in 2000, following that was well 6 and 7 in 2007.  These wells are what are commonly called “drift wells”, meaning that they are terminated in the glacial drift as opposed to being a rock well, which is set in the bedrock below the drift.  The wells are in a gravel formation with a screen to allow water to pass through while keeping the sand and gravel from entering the pump. 

The water from the three wells is pumped to the treatment plant where it moves through the aerators to oxidize the iron and manganese.  After some detention time the water passes through the iron/manganese removal filters where the iron and manganese is removed.  Once the water has passed through the iron removal filters it en­ters the membrane softening units.  A portion of the iron treated water is diverted past the membrane softening equipment and blended with the softened water to bal­ance the hardness and achieve a goal of 140 to 160 ppm or 8.18 to 9.36 gpg of hardness.  The water then travels to the 200,000-gallon concrete ground storage tank located at the facility. 

On its way to the ground storage tank chlorine is applied.  The chlorine is added as a disinfectant to prevent the presence of any bacteriological contamination in the ground storage tank and piping.  Approximately 0.50 ppm of fluoride is added with the naturally occurring fluoride of 0.20 ppm for healthier teeth and bones.  Also added is a poly-phosphate blend to help prevent the corrosion of residential plumbing and distribution system piping.  The water is metered and the chemicals are weighed every-day to ensure proper chemical dosages.

Source Water Vulnerability Assessment:

Your water comes from 3 groundwater wells, each over 50 feet deep.  The State performed an assessment of our source water to determine the susceptibility or the relative potential of contamination.  The susceptibility rating is on a seven-tiered scale from “very-low” to “very-high” based on geologic sensitivity, well construction, water chemistry and contamination sources.  The susceptibility of our source is considered as having a high geological sensitivity.

Potential sources of contamination include groundwater discharge permit sites; several small and large quantity hazardous waste generator sites; several Underground Storage Tank sites; and hazardous waste facilities.  Abandoned wells provide a direct conduit for surface runoff and contaminants to easily reach the groundwater and may pose a potential problem.  We are making efforts to protect our sources by conducting an active Wellhead Protection Program that supports management of existing or potential sources of contamination in the Wellhead Protection Program Area.  Known sources of contamination within the WHPA are being re mediated to prevent movement of contamination to the municipal wells.  If you currently have or know of an abandoned well, please notify the Water Department or your local health department for guidelines on the procedure to cap the well head.  

To obtain a copy of this report or request more information, please contact John Powell at the City of Chelsea Water Department at 734-475-1771.

Contaminants and their presence in water: 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 (800-426-4791).

• Sources of drinking water:  The sources of drinking water (both tap water and bottled water) include rivers, lakes, streams, ponds, reservoirs, springs, and wells.  Our water comes from wells.  As water travels over the surface of the land or through the ground, it dissolves naturally-occurring minerals and, in some cases, radioactive material, and can pick up substances resulting from the presence of animals or from human activity.
• Contaminants that may be present in source water include:
• Microbial contaminants, such as viruses and bacteria, which may come from sewage treatment plants, septic systems, agricultural livestock operations and wildlife.
• Inorganic contaminants, such as salts and metals, which can be naturally-occurring or result from urban storm water runoff, industrial or domestic wastewater discharges, oil and gas production, mining or farming.
• Pesticides and herbicides, which may come from a variety of sources such as agriculture and residential uses which may come from a variety of sources such as agricultural, urban storm-water runoff, and residential uses.
• Radioactive contaminants, which are naturally occurring or be the result of oil and gas production and mining activities.
• Organic chemical contaminants, including synthetic and volatile organic chemicals, which are by-products of industrial processes and petroleum production, and can also come from gas stations, urban storm water runoff, and septic systems.
• Vulnerability of sub-populations:  Some people may be more vulnerable to contaminants in drinking water than the general population.  Immune-compromised persons such as persons with cancer undergoing chemotherapy, persons who have undergone organ transplants, people with HIV/AIDS or other immune systems 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/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 (800-426-4791).

In order to ensure that tap water is safe to drink, EPA prescribes regulations that limit the number of certain contaminants in water provided by public water systems. Food and Drug Administration regulations establish limits for contaminants in bottled water which provide the same protection for public health.

Water Quality Data

The table below lists all the drinking water contaminants that we detected during the 2025 calendar year.  The presence of these contaminants in the water does not necessarily indicate that the water poses a health risk.  Unless otherwise noted, the data presented in this table is from testing done January 1 – December 31, 2025.  The State allows us to monitor for certain contaminants less than once per year because the concentrations of these contaminants are not expected to vary significantly from year to year.  All of the data is representative of the water quality, but some are more than one year old.

Terms and abbreviations used below:

• Maximum Contaminant Level Goal (MCLG):  The level of a contaminant in drinking water below which there is no known or expected risk to health.  MCLGs allow for a margin of safety.
• 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 Residual Disinfectant Level (MRDL):  means the highest level of a disinfectant allowed in drinking water.  There is convincing evidence that addition of a disinfectant is necessary for control of microbial contaminants.
• Maximum Residual Disinfectant Level Goal (MRDLG):  means 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.
• N/A:  Not applicable   ND:  not detectable at testing limit ppb:  parts per billion or micrograms per liter ppm:  parts per million or milligrams per liter pCi/L:  picocuries per liter (a measure of radioactivity). gpg: grains per gallon
• Action Level (AL):  The concentration of a contaminant which, if exceeded, triggers treatment or other requirements that a water system must follow.
• Treatment Technique (TT):  A required process intended to reduce the level of a contaminant in drinking water.
• Running Annual Average (RAA) – Four quarter running annual average for chlorine residual in

       the distribution system.

All results are in parts per million (ppm) unless otherwise noted

*Unregulated contaminants are those for which EPA has not established drinking water standards.  Monitoring helps EPA to determine where these contaminants occur and whether it needs to regulate those contaminants.

Information about lead: Lead can cause serious health effects in people of all ages, especially pregnant people, infants (both formula-fed and breastfed), and young children. Lead in drinking water is primarily from materials and parts used in service lines and in home plumbing. The City of Chelsea is responsible for providing high quality drinking water and removing lead pipes but cannot control the variety of materials used in the plumbing in your home. Because lead levels may vary over time, lead exposure is possible even when your tap sampling results do not detect lead at one point in time. You can help protect yourself and your family by identifying and removing lead materials within your home plumbing and taking steps to reduce your family’s risk. Using a filter, certified by an American National Standards Institute accredited certifier to reduce lead, is effective in reducing lead exposures. Follow the instructions provided with the filter to ensure the filter is used properly. Use only cold water for drinking, cooking, and making baby formula. Boiling water does not remove lead from water. Before using tap water for drinking, cooking, or making baby formula, flush your pipes for several minutes. You can do this by running your tap, taking a shower, doing laundry or a load of dishes. If you have a lead service line or galvanized requiring replacement service line, you may need to flush your pipes for at least 5 minutes to flush water from both your home plumbing and the lead service line. If you are concerned about lead in your water and wish to have your water tested, contact The City of Chelsea at 734-475-1771 for available resources. Information on lead in drinking water, testing methods, and steps you can take to minimize exposure is available at https://www.epa.gov/safewater/lead

Monitoring and Reporting Requirements: The State and EPA require us to test our water on a regular basis to ensure its safety.  The City of Chelsea Water Department met all the monitoring and reporting requirements for 2025. We will update this report annually.  Copies are available at the City of Chelsea Offices and on the city website or by contacting the City of Chelsea Water Department at 734-475-1771.

We invite public participation in decisions that affect drinking water quality.  The Chelsea City Council meetings are held the First and Third Monday of each month at 7:00 pm.  For more information about your water, or the contents of this report, contact City of Chelsea Water Department. For more information about safe drinking water, visit the U.S. Environmental Protection Agency at www.epa.gov/safewater/.

Water service line material: is available at https://cms3.revize.com/revize/chelseami/Master%20Line%20Inventory2025.pdf?t=202601151013140&t=202601151013140

                                                                                                                                                                              During the past year we were required to conduct (1) Level 1 Assessment. (1) Level 1 Assessment was completed. In addition, we were required to take (2) corrective actions and we completed (2) of these actions.

Coliforms are bacteria that are naturally present in the environment and are used as an indicator that other,       

potentially harmful, waterborne pathogens may be present or that a potential pathway exists through which contamination may enter the drinking water distribution system. We found coliforms, indicating the need to look for potential problems in water treatment or distribution. When this occurs, we are required to conduct assessment(s) to identify problems and to correct the problems that were found during these assessments.