Citywide Service Line Material Identification

Service Line Inventory - Identifying Unknowns via Potholing

The U.S. Environmental Protection Agency (EPA) Revised Lead and Copper Rule (LCRR) requires all public water suppliers to inventory the type of material used in every water service line connected to their water system. The City of Portsmouth submitted its initial inventory of service line materials in October 2024 and has since continued to identify materials that were unknown at that time.

Due to the split ownership of a domestic water service, both the city-owned and customer-owned portions require inspection to meet regulatory compliance (see graphic below). While the customer-owned side of a service line can be visually inspected at the entry point of a home or place of business, the city-owned side must be excavated. This is accomplished using a vacuum truck to excavate around the shutoff valve so the service line - on both sides - can be identified. This process, referred to as “potholing,” disturbs the soil and pavement around the valve. Impacts will be minimized, and the excavations will be backfilled, loamed, seeded, and patched as needed.

This potholing effort, performed in some areas of the City last year, is expanding to targeted areas where service line materials are still unknown. Since some of these neighborhoods were housing development projects where homes were all built around the same time, not all of the services need to be exposed: only a statistically representative subset. Service lines will be randomly selected in these zones of the water distribution system, and letters are sent directly to the affected properties to inform them of the potholing activities.

What to expect on day of excavation (1-2 hours of work, depending on location of service line):

  1. First, the distribution crew arrives onsite and sets up equipment.
  2. Using the vacuum excavator, the crew creates an approximately 18-inch diameter hole to access the service line.
  3. The team visually inspects and documents the service line material, taking photographs for recordkeeping.
  4. If necessary, using specialized tools, the team replaces the curb box and rod, leaving the location with renewed infrastructure.
  5. Finally, the excavation is carefully backfilled, and the site is restored. 

 

This work is expected to continue across the City over the next five years, until all service line materials have been identified in compliance with EPA requirements. If you have any questions or concerns about this effort, please contact Mason Caceres, Assistant Water Resource Manager, at 603-312-3804 or mecaceres@portsmouthnh.gov.