Lead & Copper Corrosion Control Program Update

December 10, 2018

Portsmouth water remains in compliance with quality requirements for lead

The City of Portsmouth completed its recent round of sampling under the Lead & Copper monitoring program and is pleased to report that the water system remains in compliance with the current lead and copper regulations. This sampling is required by the U.S Environmental Protection Agency (EPA) under the Safe Drinking Water Act (SDWA) and is administered by NH Department of Environmental Services (NHDES) through the Lead and Copper Rule (LCR). It was accomplished through a collaboration between Portsmouth Public Works Water Department and our customers. While eliminating all lead in the system is the overall goal, recent sample results show the continued success of the water system’s corrosion control program which is actively monitored to ensure water reaching our customers taps is safe to drink.

The program has been in place since 1993. The City’s low calculated averages of lead through the initial years of sampling data enabled the City to go on a reduced monitoring schedule in 2007. Since then, the City has been required to conduct this sampling program on a triennial basis requiring 30 samples per round. However, due to an upgrade at our Greenland Well facility in 2017, our sampling schedule was adjusted, requiring two rounds of 60 samples be collected in 2018. The first round took place April into June, the second in August through November of this year. Of the 123 samples taken at 84 different customer locations 87 percent were “non detect” (less than one parts-per-billion (ppb)) for lead.

The following table summarizes these test results:

2018 lead sample results

When a water sample contains detectable levels of lead, we offer follow-up sampling to the homeowner in order to verify the original result was valid, help determine if flushing for a period of time would be effective at reducing the lead concentration, and to help identify the potential source areas in the house i.e., kitchen versus the bathroom tap. We work with the property owner to assess their plumbing and find ways for them to reduce potential exposure, like changing out suspected plumbing, pipes or other fixtures that might contain lead, flushing prior to using water for consumption, or checking to ensure your home electrical system is grounded properly.

All water used for these tests is taken by the homeowner following the sample guidelines. The samples are then collected by the City’s water operations staff and analyzed by a state certified laboratory. Beginning in 2019, the City will be required to conduct this sampling program on an annual basis, requiring 30 samples per round.



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 (ppm) for copper, respectively at the 90th percentile of samples.

The City of Portsmouth implemented a Lead & Copper Corrosion Control Program in 2003 and has been in compliance requirements since its inception.  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 measureable quantities of lead or copper.

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

Date Sampling Frequency Lead 90th percentile (ppb) Copper 90th percentile (ppm)
2018 Twice per year 1 0.162
2016 Triennial (once every 3 yrs.) 7 0.135
2013 Triennial (once every 3 yrs.) 1 0.110
2010 Triennial (once every 3 yrs.) 1 0.130
2007 Annual 5 0.185
2006 Annual 5 0.194
2005 Annual 13 0.239
July 2004 Semi-Annual 5 0.261
January 2004 Semi-Annual 13 0.291
July 2003 Semi-Annual 16 0.296
January 2003 Semi-Annual 12 0.252

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 bi-weekly 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 New Hampshire Department of Environmental Services (NHDES). Of the 60 sites identified, routine sampling of 30 of these residential sites is required. 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 our Greenland Well facility, the City of Portsmouth is required to sample 60 residences for lead and copper twice in 2018 (January to June and July to December). This sampling requirement is due only to regulations associated with new sources, not that there is any expectation of a change in the water quality. Therefore, the first round of testing took place April into June, the second in August through November of this year. Of the 123 samples taken at 84 different customer locations 87 percent were “non detect” (less than one parts-per-billion (ppb)) for lead. No sites were above the 15 ppb action level set by the EPA.

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 OneStop website: http://des.nh.gov/onestop/index.htm

Information about Portsmouth’s Corrosion Control Program has been distributed annually since its inception. Lead and copper information is summarized on the Portsmouth Water Division Annual Water Quality Reports: https://www.cityofportsmouth.com/publicworks/water/drinking-water-quality

Additional information about lead and copper corrosion control is available from the NHDES: http://des.nh.gov/organization/divisions/water/dwgb/lead-copper/index.htm

And from the EPA: http://www.epa.gov/dwreginfo/lead-and-copper-rule#additional-resources

Testing Lead in Drinking Water in Schools and Daycares

Senate Bill 247 was signed into law on February 8, 2018. This law requires, among other actions, that all schools and licensed childcare facilities test lead in drinking water at all locations where water is available for consumption by children. The first round of testing is required to be completed by July 1, 2019, and every 5 years thereafter, until at least 3 rounds are below the standard. Any locations showing 15 ppb or higher must be remediated.

City of Portsmouth water staff have previously assisted the City’s school department in a sampling effort performed in 2016. All Portsmouth schools had their water tested and any with detections were evaluated for plumbing replacements. Tests done for the presence of lead in the water at all city schools came back below the federal drinking water regulatory limit. In an April 26, 2016 Portsmouth Herald article, Superintendent Stephen Zadravec acknowledged tests did reveal the presence of lead below the limit of 15 parts per billion at one sink and two classroom bubblers. He noted that those locations were taken out of service and the plumbing was replaced.



Table of test results