July 24, 2018
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|
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.
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.
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:
- 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.
- Buildings including multiple-family structures containing copper pipes with lead solder installed after 1982 but before 1988, or are service by lead service lines.
- 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 City of Portsmouth collected the most recent round of lead and copper samples during the first six months of 2018.
62 sites were sampled during the first six months of 2018. Of those, 55 sites were “non detect” for lead, 4 sites were below 2 parts-per-billion (ppb) and 3 sites were between 3 to 5 ppb. No sites were above the 15 ppb action level set by the EPA.
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
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.