Annual Drinking Water Quality Report

Public Water System I.D. 7210002

Serving the residents of the Borough of Carlisle and applicable portions of Middlesex and North and South Middleton Townships

Every year, the Borough of Carlisle publishes a Consumer Confidence Report (CCR) to inform you about the water quality produced and delivered by the Borough of Carlisle Water Treatment Plant. Safe water is vital to our community and we want you to understand the information on the source of your water, what's in it, and the health risks associated with any contaminants that may be found.

Below you will find highlights from the 2025 Consumer Confidence Report. You can view the full report here.

Table of Contents

1. About Your Water
2. How We Keep Your Water Safe?
3. Frequently Asked Questions
4. Your Role in Water Quality
5. Water Data for 2025
6. Quarterly Board Meetings
7. Questions or Concerns
8. Violations

About Your Water

Where Your Drinking Water Comes From

Most drinking water in the United States comes from a river, a lake, or from an underground well. The water we provide to you comes from the Conodoguinet Creek, which is surface water. Our surface water treatment plant is located at 165 Long’s Gap Road in Carlisle, PA.

We Protect the Source

Making the water safe to drink starts by protecting the place it comes from. Our water source is surface water from the Conodoguinet Creek in Shot of Conodoguinet CreekCarlisle, Cumberland County, Pennsylvania. The water is treated at our Carlisle Borough

Municipal Authority filtration plant. A Source Water Assessment of the Conodoguinet Creek, which supplies water to the Carlisle Borough Municipal Authority filtration plant, was completed by the PA Department of Environmental Protection (Pa. DEP). The Assessment has found that the Conodoguinet Creek Intake is potentially most susceptible to agriculture, urban runoff, and industrial discharges. Overall, the Conodoguinet Watershed has a moderate risk of significant contamination. A summary report of the Assessment is available here. Complete reports were distributed to municipalities, water suppliers, local planning agencies, and PA DEP offices. Copies of the complete report are available for review at the PA DEP Southcentral Regional Office, Records Management Unit at (717)705-4732.

What Is in Your Source Water

The sources of drinking water (both tap water and bottled water) include rivers, lakes, streams, ponds, reservoirs, springs, and 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 stormwater 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, 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, and can also come from gas stations, urban stormwater runoff, and septic systems.
• Radioactive contaminants, which can be naturally occurring or be the result of oil and gas production and mining activities.

To ensure that tap water is safe to drink, the Environmental Protection Agency (EPA) prescribes regulations, which limit the amount of certain contaminants in water provided by public water systems. The Food and Drug Administration (FDA) regulations establish limits for contaminants in bottled water, which must provide the same protection for public health.

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 Environmental Protection Agency's Safe Drinking Water Hotline at 800-426-4791.

Sampling and Testing

We take more than 1,500 samples across our water system. We are testing for bacteria, metals, and chemicals to make sure the water continues to be safe to drink.

Bacteria

We conduct regular bacteria testing, as required by law, by collecting samples from ten designated locations within the water system for analysis. More thorough testing, evaluation, and action is required if bacteria is found in even a small percentage of tests.

Disinfection by-products (Trihalomethane (THM) or Haloacetic Acids (HAA))

Four times per year, we test for byproducts of the disinfection process. When chlorine, the disinfectant we use to protect against the water of bacteria and viruses, starts to break down in the water, it can form new compounds. These compounds, trihalomethanes (THM) and haloacetic acid (HAA), have been known to cause cancer at high levels. The legal limit for drinking water is 80 parts per billion and 60 parts per billion respectively. We test for these compounds at four different locations in the water system.

 Lead and Copper

We take water samples from thirty different homes in our system every three years to test them for lead and copper.

How We Keep Your Water Safe

How we clean the water is similar to other water treatment plants in the U.S. and is required by law.

The Borough of Carlisle Water Treatment Plant follows these five steps:

Graphic Showing Thickening Process

Step 1: Pre-Treatment

The water we collect is screened from the creek and brought into our treatment plant where chemicals are added in safe amounts to cause small particles of pollutants present to stick to one another, forming larger particles. This is called coagulation. 

Step 2: Settling 

Over time, the larger particles become heavy enough to fall (or settle) to the bottom of the tank where they are removed. 

Step 3: Filtering

The remaining water flows through filters made of layers of fine materials of sand, anthracite coal, garnet, and types of media. These layers stop even smaller particles of pollutants from getting through, and only very clear water is left.

Step 4: Disinfection

Bacteria or viruses may still be present in the water, so a chemical, chlorine, is added to remove them. An additional chemical is also added at a safe level to protect the pipes from corrosion as the water travels to your home. 

Step 5: Storage and Delivery

Once the disinfection process is complete, the treated water is stored until needed. Storage usually takes place in an underground storage tank called a “clear well”, and also in elevated storage tanks that are visible around town. The stored water is sent through underground pipelines all over town in what is called a “distribution system”. 

Another look at how water travels from the source to your homep

Frequently Asked Questions About Water Treatment

Your Role in Water Quality

Check Your Home or Business's Plumbing for Lead and Copper

We work hard to deliver high-quality water to your property. Once it passes your meter, however, it enters your home's environment—beyond our control but under yours.

Some of the things that can change the water quality on your property include your plumbing and pipe material, how long you go without running the water, and whether or how you connect outdoor hoses to your home’s water supply. Lead can cause serious health problems, especially for pregnant women and young children. Lead in drinking water is primarily from materials and components associated with service lines and home plumbing. The Borough of Carlisle is responsible for providing high-quality drinking water and removing lead pipes from our distribution system but cannot control the variety of materials used in plumbing components in your home. You share the responsibility for protecting yourself and your family from the lead in your home plumbing. You can take responsibility by identifying and removing lead materials within your home plumbing and taking steps to reduce your family's risk. Before drinking tap water, flush your pipes for several minutes by running your tap, taking a shower, doing laundry or a load of dishes. You can also use a filter certified by an American National Standards Institute accredited certifier to reduce lead in drinking water. If you are concerned about lead in your water and wish to have your water tested, contact the Borough of Carlisle Water Resources Department at 717-249-4422. Information on lead in drinking water, testing methods, and steps you can take to minimize exposure is available at http://www.epa.gov/safewater/lead. The Borough of Carlisle prepared a service line inventory that includes the type of material contained in each service line in our distribution system. This inventory can be accessed on our website at www.carlislepa.org/servicelinematerial.

If you have not filled out your lead service line information survey yet, please visit our website at www.carlislepa.org/servicelinematerial or contact Sara Crawshaw at 717-240-6991.

Look Out for Special Populations

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 healthcare 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 at 800-426-4791.

Your Water Data

We routinely monitor for contaminants in your drinking water according to federal and state laws. The following tables show the results of our monitoring for the period of January 1 to December 31, 2025. The State allows us to monitor for some contaminants less than once per year because the concentrations of these contaminants do not change frequently. Some of our data is from prior years in accordance with the Safe Drinking Water Act. The date has been noted on the sampling results table.

We have never gotten a result that did not meet requirements.

If we did, we would act fast to protect you and your family. We would contact our customers immediately through various media outlets.

This report may contain terms and abbreviations that you are not familiar with. We have provided definitions for some of the terms below to help you better understand the data.

MCL - Maximum Contaminant Level: This is the highest level allowed of a pollutant in drinking water. MCLs are set as close as possible to the goal using the best available technology.

MCLG - Maximum Contaminant Level Goal: The goal level of a pollutant in drinking water. Below this amount, there is no known or expected health effect.

PPB - Part Per Billion = 1 drop of water in an Olympic-sized swimming pool

PPM - Part Per Million = 1 drop of water in a hot tub

MCL - Maximum Contaminant Level: This is the highest level allowed of a pollutant in drinking water. MCLs are set as close as possible to the goal using the best available technology.

MCLG - Maximum Contaminant Level Goal: The goal level of a pollutant in drinking water. Below this amount, there is no known or expected health effect.

PPB - Part Per Billion = 1 drop of water in an Olympic-sized swimming pool

PPM - Part Per Million = 1 drop of water in a hot tub

PPM - Part Per Million = 1 drop of water in a hot tub

PPM - Part Per Million = 1 drop of water in a hot tub

NTU - Nephelometric Turbidity Units: Turbidity is measured with an instrument called a nephelometer. Measurements are given in nephelometric turbidity units.

PPT - Part Per Trillion = 1 drop of water in a lake that’s 6 square acres

MCL - Maximum Contaminant Level: This is the highest level allowed of a pollutant in drinking water. MCLs are set as close as possible to the goal using the best available technology. Levels set by Pennsylvania Department of Environmental Protection.

MCLG - Maximum Contaminant Level Goal: The goal level of a pollutant in drinking water. Below this amount, there is no known or expected health effect.

Unregulated Contaminant Monitoring Rule 5

The EPA specified monitoring for 29 per- and polyfluoroalkyl substances (PFAS) and lithium to be monitored every quarter of 2023. These contaminants are those that do not yet have a drinking water standard set by EPA. The purpose of this monitoring is to help EPA decide whether the contaminants should have a standard. The PA DEP has set state standards for PFOS at 18 ppb and PFOA at 14 ppb. The following table lists the contaminants that our testing detected in 2023.

The Borough of Carlisle pilot tested two treatment options for PFAS removal – Granulated Activated Carbon (GAC) and Ion Exchange Resin (IX) – to determine which one is appropriate for our water source.  Treatment is planned to achieve non-detectable levels of PFAS. 

PPB - Part Per Billion = 1 drop of water in an Olympic-sized swimming pool

PPT - Part Per Trillion = 1 drop of water in a lake that’s 6 square acres

MRL – Minimum reporting limit

Quarterly Board Meetings

We need your understanding and support to be successful. We hope you will get involved with us on projects, programs, and policies. You are welcome to attend our Municipal Water Authority meetings. We meet on the third Wednesday of January, April, and July at 5:00 PM and at 4:00 PM the third Wednesday of October at the Carlisle Water Treatment Plant at 165 Longs Gap Road. The October meeting includes an annual facility tour open to the public. We always make time to hear from guests and answer questions, so please join us to learn more about what we are working on. Your input is important to us!

Questions or Concerns

We want our residents to be informed about their drinking water. If you have any questions concerning the drinking water results and its operations, please contact Sara Crawshaw, Borough of Carlisle Laboratory Supervisor, at 717-240-6991, or the Borough offices at 717-249-4422.