Lead & Copper Corrosion Control Program Update

October 7, 2023

During this October 2023 Lead Poisoning Awareness Week the City of Portsmouth is offering homeowners information resources about testing for lead in their paint and water. For details go to more information. For details on free home water testing kits, go to this flyer

PROTECT YOUR TAP: 10-minute lead test

The U.S. EPA and NHDES created this Protect Your Tap: 10-minute lead test online guide that walks homeowners through a series of steps to see if they have lead pipes bringing water into their home, how to reduce their exposure to lead and how to get their water tested. 

The City of Portsmouth implemented a Lead & Copper Corrosion Control Program in 2003 and has been in compliance with its requirements since then. Sampling conducted in 2022 of 30 taps throughout the Portsmouth water system found just four locations with measurable concentrations of lead (all under 5 ppb and well below the 15 ppb requiring additional action) and 26 locations with no lead detected.

The general purpose of the Lead & Copper Corrosion Control Program is to minimize the potential for water supplied by the City to leach potentially harmful metals such as lead and copper from pipes, fixtures and solder containing lead. The primary source of lead and copper in drinking water is plumbing systems in houses and other privately owned buildings. The City of Portsmouth water supply sources do not contain measurable quantities of lead.

The following is a summary of the lead and copper compliance testing results and sampling schedule for the Portsmouth Water System since the Corrosion Control Program has been in place:

Lead & Copper Compliance Data

Health Impact of Lead

Health impacts due to the consumption of lead or copper via drinking water have been well documented. Lead exposure is known to cause internal organ damage, behavioral disorders, an increased risk of heart disease and an interference with physical development of infants. Copper has the potential to cause gastrointestinal disturbance from short-term exposure and liver or kidney damage from long-term exposure. In response to these health impacts, the EPA set maximum levels to protect public health at 15 parts-per-billion (ppb) for lead and 1.3 parts-per-million for copper, respectively at the 90th percentile of public water system samples. 

Corrosion Control Inhibitor 

To reduce the potential for City water to leach lead and copper from plumbing systems, a corrosion control inhibitor is added to the water supply. The corrosion inhibitor used by the City of Portsmouth is an orthophosphate/polyphosphate blended chemical that is a National Sanitation Foundation (NSF) Standard 60 additive approved for drinking water. The inhibitor creates a coating on the walls of distribution pipes and house plumbing to minimize the potential for metals (including lead and copper) to leach from pipes into the drinking water. It adds no noticeable taste to water. The optimized concentration in the Portsmouth water distribution system is 1 mg/L – as orthophosphate.

Ongoing Monitoring 

Portsmouth Water Treatment Operators continuously monitor the concentration of orthophosphate in the system. Automated analyzers, field measurements and laboratory verification samples are analyzed to ensure optimized concentrations are maintained in the system. Water quality parameters that are factors in the corrosivity of water include alkalinity, hardness, dissolved solids, and pH. These parameters are monitored quarterly from the supply sources and selected locations throughout the distribution system.

Compliance Sampling 

As part of the Corrosion Control Program development, locations of representative residential household sampling sites were identified based on the three tier priority ranking defined by the US Environmental Protection Agency (USEPA). Only those sampling sites that are approved by the New Hampshire Department of Environmental Services (NHDES) can be used for compliance sampling. The tiered priorities are based upon the following site characteristics:

  1. Single-family structures containing copper pipes with lead solder installed after 1982 but before 1988, or containing lead pipes, or are served by lead service lines. 
  2. Buildings including multiple-family structures containing copper pipes with lead solder installed after 1982 but before 1988 or are service by lead service lines. 
  3. Single-family structures containing copper pipes with lead solder installed before 1983. 

During the first two years of the Corrosion Control Program, lead and copper compliance samples were collected two times per year at the 30 selected sampling sites. Upon confirmation of the effectiveness of the Corrosion Control Program, sampling was reduced to annually from 2005 through 2007, and to every three years thereafter. 

In 2018, due to the upgrade at the Greenland Well facility, the City of Portsmouth was required to sample 60 residences for lead and copper twice in 2018 (January to June, and July to December). This sampling requirement was subsequently reduced to 30 residences, every year.  

In July and August of 2022, 30 sites were sampled and of these, 26 sites were “non-detect” for lead, two sites were below 2 ppb, and two sites had between 2 and 5 ppb of lead.

Public Outreach 

All of the participants in the residential compliance sampling program receive results of the lead and copper analyses with an explanation. Lead and copper results are available on the NHDES website.

Information about Portsmouth’s Corrosion Control Program has been distributed annually since its inception. Lead and copper information is summarized in the Portsmouth Water Division Annual Water Quality Reports.  

Go to additional NHDES information about lead and copper corrosion control.

Go to additional EPA lead and copper rule resources.

Testing Lead in Drinking Water in Schools and Daycares 

New Hampshire Senate Bill 247, signed into law on February 8, 2018, requires that all schools and licensed childcare facilities test for lead in drinking water at all locations where water is available for consumption by children. The first round of testing was completed by July 1, 2019. On July 8, 2022, House Bill HB-1421 was signed by the Governor. This law reduces the acceptable lead standard for schools and daycares from 15 ppb to 5 ppb, and sets forth sampling and remediation requirements. Any locations that have 5 ppb or higher of lead must be remediated. These programs are being administered by the NHDES and they are working directly with schools and daycares to gain compliance with this rule. All sample results are available on the NHDES website.


Pie chart 2022