DPH Consent Agreement
Update – March 2021:
In February 2017, Norwich Public Utilities (NPU) entered into a Consent Agreement with the State of Connecticut’s Department of Public Health (DPH), requiring that we notify customers of improvements being made to our water system to address an ongoing water quality issue.
Since 2015, NPU has occasionally failed to meet the Stage 2 Disinfection Byproduct Rule at all locations throughout our water distribution system. Disinfection byproducts develop when microscopic levels of naturally occurring organic material remain in the drinking water after the purification process and react with chlorine used for their elimination and overall system disinfection.
From time to time, NPU has experienced exceedances of the disinfection byproducts threshold level of 80 parts per billion. Exceedances have typically occurred at one or two locations in the system by values of 1 to 9 parts per billion (this exceedance is the equivalent of 1 to 9 cents per $1,000,000). When these exceedances occur, NPU notifies our customers and posts information on our website.
NPU works closely with the DPH regarding all water quantity and quality issues including the commissioning of any new infrastructure or treatment systems or processes. Some recent infrastructure improvements include:
- Constructed a new 1 million gallon water storage tank
- Relined approximately 3,700 linear feet of transmission main
- Replaced outdated pumps, drives, piping, and chemical feed systems
- Converted from chlorine gas to sodium hypochlorite in our treatment process
- Replaced a 50+ year old 5 million gallon water tank located in Mohegan Park with a smaller 2.5 million gallon tank
- Activated an active mixing/aeration system in the water storage tank that serves the Taftville/Occum high service area
- Installed a new water transmission main from Leffingwell Road to Noble Hill Road to Rt. 82 in Bozrah eliminating a long dead-end and an undersized main within the distribution system, thereby improving flows and reducing water age on Salem Turnpike
- Rehabilitated and modernized the filtration system at one purification plant.
Additional NPU is installing a new water filtration system at our water treatment plant in Montville, CT.
These improvements, as well as the associated operational changes were documented in a plan that was provided to and approved by the DPH.
As part of the Consent Agreement, NPU will provide customers with quarterly updates of the progress made toward reaching consistent compliance with the Stage 2 rule as well as updates on the infrastructure improvements.
During the current quarter testing, NPU was compliant with the Stage 2 Disinfection and Disinfection By-Product Rule (DDBPR) at all compliance locations within our system.
Frequently Asked Questions:
1. What is the issue with NPU’s water quality?
Based on ongoing testing, NPU has intermittently exceeded the established Stage 2 Disinfection Byproduct Rule as set by the U.S. Department of Environmental Protection (EPA).
Over the past thirty months, compliance was achieved at all compliance testing locations.
2. Is it safe to drink?
Yes. NPU’s water supply remains safe and the levels by which we’ve occasionally exceeded the standards do not pose a health risk to our customers.
3. What caused this to happen?
Total Trihalomethanes (TTHMs) are created when methane from organic matter in the water system interacts with chlorine, which is used by NPU to disinfect the water before it is sent to our customers.
4. What were the results of this testing?
Our testing revealed that NPU’s level of TTHMs is occasionally slightly above the allowable amount as set by the EPA.
The EPA’s standard is 0.080 mg/L (milligrams per liter). Compliance has been achieved at all compliance testing locations since the 4th quarter 2018. In the past, NPU’s levels have occasionally exceeded the 0.080 mg/L standard.
5. What is NPU doing to resolve this issue?
This is a complex challenge for NPU that requires us to develop a detailed strategy to address the issue. Our plans to address this issue have been reviewed and approved by the State of Connecticut’s Department of Health.
We consistently evaluate and adjust, as necessary, our operational and logistical options with the goal of consistently meeting the DPH and EPA standards. Procedures such as a targeted flushing process with other means of managing water demand that will shorten the length of time water remains in our system (water age.) The level of TTHMs in water increases with the length of time the water remains in our system.
We have already initiated several projects that will give us better tools to address this issue, including capital projects to modernize and improve the strength of our water system:
- The replacement of very large pumps at our water treatment facility in Lebanon; this work has been completed and is providing NPU with greater operational flexibility.
- Decommissioning of a large water storage tank in the center of Norwich and replacing it with a smaller tank. This decreased water age and improve flows throughout our distribution system. The tank was activated in late July 2018.
- Installation of an aeration/mixing system in our Occum water storage tank. The project was activated in September 2018.
- Replacement of an aged transmission main and small diameter water main to improve flow and reduce water age in the vicinity of Salem Turnpike near the Norwich-Bozrah side of the system.
- Rehabilitation and modernization of the sand filtration system at the water treatment plant in Lebanon.
- The installation of a new water filtration system at our water treatment plant in Montville. This project is in construction.
6. Do I need to boil my water?
No. This is not a bacteria-related issue so boiling water is not necessary.
7. Am I putting myself / my family in danger by drinking this water?
Not at all. NPU’s water supply remains safe and the levels by which we’ve occasionally exceeded the standards do not pose a health risk to our customers.
8. When will you know if the problem is fixed?
We will continue to monitor this situation very closely and are regularly measuring the levels of disinfection byproduct in our system.
Our results will be reported to the State of Connecticut’s Department of Public Health as required by state regulation.
Results of quarterly testing will also be posted on this webpage along with the status of our projects and efforts to consistently meet the standards.
9. Will NPU give me water to drink while this issue is being resolved?
No. NPU’s water remains safe for human consumption.
10. Will my home’s water filtration system help with this issue?
No. A standard residential filtration system will not help address this issue.
11. Is there any concern in having the water come in contact with my skin?
No. NPU’s water is safe for human consumption and use.
12. Is this water safe for my pets?
Yes. NPU’s water is safe for consumption and use.
13. How long has NPU known about this issue?
Tests are performed quarterly in accordance with DPH and EPA sampling and testing protocols.
14. What if NPU’s water does not return to the required level in three months?
While compliance was achieved in the quarter ending March 31, 2020, NPU will continue to take steps to consistently meet the EPA standards and continue to provide notification to our customers as we continue to work on this important issue.