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 approaches currently in use in some communities. All of the practices in the following table rely on households adhering to the practices described – either conducting flushing, installing and maintaining filters, and participating in sampling.  A number of the practices rely in part on sampling water in the home for lead.  It is difficult to be certain that lead is or is not present from a single sample.  Moreover, it is not clear from such sampling where lead is coming from (e.g., debris, solder, brass fittings, etc.); this limitation is balanced against the challenges of implementing a more elaborate protocol.  These practices were, in general, developed to reduce lead exposure after partial lead service line replacement and are being adapted toward full lead service line replacement.  There is ongoing research focused specifically at complete lead service line replacement practice.  ​
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,  customer again collects 12 consecutive
1-liter samples after six-hour stagnation, plus one well-flushed sample.
 (POU  filter used in interim.)
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 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
Typical 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
​AWWA standard C810-17 (household behavioral change and testing water for lead)
Maintenance for three months following replacement includes 30 minute flushes once every two weeks or at other intervals based on monitoring results if available; daily practice would also include flushing the tap prior to first use for 3 minutes for six months or until lead sample results show lead levels below regulatory level; follow-up sampling can commence within one month of LSL replacement.
Precautionary strategy based on assumption of elevated lead
Relies on customer adherence; and
may be community specific duration.
The AWWA standard is an ANSI certified standard and has been referenced in some states and EPA guidance to individual systems.
Relevant Resources: