Norwich Public Utilities (NPU)

A municipally owned utility serving Norwich, CT with
natural gas, electricity, water and sewer services.

Home For My Home DPH Consent Agreement

DPH Consent Agreement

December 13, 2017

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.

clear-water-glassSince 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 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·         Replaced outdated pumps, drives, piping, and chemical feed systems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

Additional projects underway include replacing the 50+ year old 5 million gallon water tank located in Mohegan Park with a smaller 2.5 million gallon tank (scheduled for activation in mid-January 2018) and installation of an active mixing/aeration system in the water storage tank that serves the Taftville/Occum area (scheduled to begin construction in early January 2018.)

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 quarters ending December 31, 2016, March 30, 2017 and June 30, 2017, NPU was compliant with the Stage 2 Disinfection and Disinfection By-Product Rule (DDBPR) at all compliance locations within our system.  However, based on recent testing during the quarters ending September 2017 and December 2017 NPU has exceeded the maximum contaminant level in our water for trihalomethanes (TTHMs) as set by the US Environmental Protection Agency (EPA) at one and two locations, respectively.

Capital projects included in the Compliance Action Plan are proceeding according to schedule:

  • Mohegan Park Tank - expected completion date:  May 2018
  • Occum water storage tank aeration/mixing system - expected completion date:  May 2018
  • Stony Brook filtration improvements - expected completion date:  July 2019

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 three months, at two testing location, there has been an organic compound in our water at a slightly higher level than is allowed under federal regulations.

2. Is it safe to drink?

·         Yes. NPU’s water supply remains safe and the levels by which we’ve exceeded the standards do not pose a health risk to our customers

3. What caused this to happen?

·         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 reveals 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). NPU’s levels have, at two locations, were0.090 parts per million and 0.082 parts per million.  To put this into perspective:  the revised standard is the equivalent of 8 cents out of $1,000,000; NPU levels have been the equivalent of 9 cents and 8.2 cents out of $1,000,000.

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 are looking at our operational and logistical options that will help us consistently meet these new standards, 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 will decrease water age and improve flows throughout our distribution system.  The tank is currently in construction with an expected activation date of mid-January 2018 with a final completion date of May 2018. 
  • .      Installation of an aeration/mixing system in our Occum water storage tank.  The project has been awarded for construction and is expected to begin in early January 2018.
  • .      The installation of a new water filtration system at our water treatment plant in Montville.  The design for this project is underway and we expect to begin construction in 2018. 

 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.

1     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?

 ·         We received test results on December 6, 2017.

 14.  What if NPU's water does not return to the required level in three months?

 ·         We are taking a number of steps to meet the EPA standards and will continue to provide notification to our customers as we continue to work on this important issue.


 Download the TTHM FACT SHEET






Electric, Sewer, Water: 860-887-2555
Natural Gas: 860-887-7207
Report Utility Issue

Call Before You Dig

This service is free, it’s easy to use, and it’s the LAW!
CALL 8-1-1 Learn More

Community Matters

To view the latest Community Matters newsletter,
Document icon click here.