Steps to Ensure Replacement

was Successful  
Even if lead service lines (LSLs) are fully replaced, internal plumbing can still include lead pipe, brass, and solder that can contribute to observed lead concentrations. Corrosion control treatment by the community’s utility continues to be necessary to mitigate lead release.

​Currently, there is not a national best practice defining the length of time it is necessary for building occupants to take additional precautionary after a service line is replaced. At present, the approach being taken at the direction of EPA, states, and individual utilities is to:
When an LSL is fully removed there is no longer the question of, “Is lead coming from the LSL?” Rather the question is one of the adequacy of control measures at the time of replacement and whether there is residual lead exposure from other sources of lead in the premise plumbing.
  1. Establish a conservative approach based on available information.
  2. Collect data on lead levels before and after replacement to identify trends in:
    1. How high lead levels are post-replacement.
    2. How long lead levels, if elevated, remain so.
    3. What conditions at structures appear to influence lead levels post-replacement.
  3. Use the collected data to adjust practice.
When analyzing data to improve instructions for precautionary measures, it is important to look for community-wide trends in the data in order to guide the practice for the community’s LSL replacement effort.
Lead pipe at a curbstop. Source: Philadelphia Water
The following table lists several approaches currently in use at some utilities.
Action
Description
Pro
Con
Example Applications
​Test water for lead 
​Typical practice is to take a sample within 72 hours of replacement.  Sample intended to represent water from service line by flushing a specific volume of water or waiting for water temperature change.
Relatively fast feedback; reduces need for additional protective measures for a lengthy period.
Homeowner participation rate is low, observed concentration influenced by home plumbing and sample protocol, and designed to engage customer after partial replacement.
All water systems engaged in mandatory lead service line replacement under the Lead and Copper Rule following a partial lead service line replacement.
​Test water for lead 
Take a first-flush, tap sample 3 months after replacement. (NSF compliant filter used in interim.)
Evaluate effectiveness of flushing and post-replacement lead levels
Observed concentration influenced by home plumbing and sample protocol.
EPA Flint Safe Drinking Water Task Force Recommendations Regarding City of Flint Fast Track Plan for Lead Service Line Replacement
​Test water for lead 
​Take a first-flush, tap sample 6 months after replacement. (Pour through filter used in interim.)
Allows any remaining particles from replacement to be flushed by normal use and observations more representative of re-established water chemistry
Homeowner participation rate is low, observed concentration influenced by home plumbing and sample protocol, and designed to assess lead level after partial replacement.
DC Water Protocol following lead service line replacement (DC Water maintains a separate sampling program for customers requesting a multiple Liter sample protocol)
​Test water for lead 
Take 12 consecutive 1-liter samples after six-hour stagnation, plus a 13th well-flushed sample as soon as practical after replacement. And, after about one month, Water Quality Section will ask customer to again collect 12 consecutive
1-liter samples after six-hour stagnation, plus one well-flushed sample.
 (POU  filter used in interim.)
Relatively fast feedback; reduces  need for additional protective measures for a lengthy period, sampling protocol helps diagnose source of remaining lead, and two rounds of sampling confirms change any changes in lead levels.
​Designed to engage customer after partial replacement.
Milwaukee Protocol for Water System Activities that Impact Lead Services 
Test water for lead 
Take a first-flush, >6 hour stagnation tap sample (1) prior to and (2) after replacement (either within 24 hours or within 30 – 60 days).
Provides single sample point of comparison for before and after replacement
​Does not distinguish in-home contribution
De facto practice where water systems facilitate customer sampling on request
Household Behavior Changes
​ For 30 days post construction flush daily (including routine use) flush daily and clean aerator.  For 6-months post construction pregnant, breastfeeding or have children under the age of six should drink filtered water (NSF 53).
Precautionary strategy based on assumption of elevated lead, does not entail logistics of sampling, and premise for duration draws on overall study of lead release post construction in community
​Relies on customer adherence and may be community specific duration
Halifax Water
Relevant Resources: