Lead is a toxic metal that can cause serious health problems. One of the primary sources of lead exposure is from drinking water that has been contaminated by lead pipes or fittings. Water utilities are responsible for identifying and mapping the locations of lead pipes and service lines as well as communicating this information to the public. This is not only good practice, but is also a legal requirement under the Lead and Copper Rule Revision (LCRR) issued by the U.S. Environmental Protection Agency (EPA).
How can water utilities comply with this mandate effectively and efficiently? Dudek’s Mapping and Surveying team has developed a step-by-step guide to inform the process, including tips for leveraging Esri’s ArcGIS Utility Network when identifying lead pipe contaminants in a water distribution system.
1. Understand the EPA Mandate
The mandate requires that water utilities:
- Identify the presence and location of lead service lines within their distribution system.
- Make this information readily available to the public.
Understanding the mandate’s requirements is vital to perform lead contaminant mapping effectively and efficiently.
2. Gather Historical Data
Next, old records and maps must be reviewed to identify areas where lead pipes might have been installed. These sources may include blueprints, maintenance records, construction permits, and any previous tests or inspections.
3. Inspect and Test for Lead
For systems lacking comprehensive historical data, a physical inspection might be necessary. This may involve:
- Visual Inspections to identify any dull, gray pipes and determine whether they attract magnets. Since lead is non-magnetic, a pipe that doesn’t attract magnets could indicate the presence of lead.
- Scratch Tests to gauge the hardness of the pipe. Lead pipes are relatively soft, so if a key or coin easily scratches the pipe, it might be made of lead.
- Water Tests to determine the presence of lead in water that has flowed through the pipe.
4. Analyze the Water System with ArcGIS Utility Network
After the data is gathered and any necessary inspections have been completed, the water system must be analyzed. This step can be facilitated using Esri’s ArcGIS Utility Network, a water system management tool capable of:
- Locating Lead Pipes. Once a geospatial database of all the pipes in the water distribution system is created, ArcGIS Utility Network can be used to tag the materials of each pipe (e.g., lead, PVC, copper) and highlight the ones that are lead.
- Tracing Water Flow. If the water origin and path through the distribution system are known, ArcGIS Utility Network can trace water flow through the lead pipes.
- Identifying Affected Areas. After tracing the flow, the results can be overlayed on residential or other pertinent data layers to identify affected areas to help determine which households or areas are potentially receiving contaminated water.
- Analyzing Infrastructure Age. If the database also contains information about when each pipe was installed, the age of the pipes can be determined. Older pipes are a significant indicator for contamination, as they are prone to corrosion and may release more lead into the water.
5. Map the Water Distribution System
Once the data has been analyzed, comprehensive maps depicting the location of lead pipes and affected areas can be created. Maps should include:
- Locations with confirmed lead service lines
- Locations suspected, but not yet confirmed, to have lead lines
- Previously contaminated locations that have already been replaced or treated
When using ArcGIS Utility Network for mapping lead pipe contaminants, it’s essential to work closely with mapping and GIS experts to ensure that the data reflects real-world conditions. While the tool is capable of powerful analysis, the quality of the data determines the accuracy of the results.
6. Inform the Public
Per the EPA mandate, maps depicting contaminated areas must be made available to the public. This step also provides an opportunity to communicate potential risks and mitigation steps.
7. Develop Pipeline Replacement Strategy
While not technically part of the mandate, it’s good practice (and sometimes required by local or state regulations) to have a plan in place to replace or treat lead service lines. The location and age of lead pipes, as well as the number of affected households, should be considered when prioritizing segments for replacement. ArcGIS Utility Network can assist in planning optimal routes for replacement work and minimizing disruption to the water network during the process.
Identifying and eliminating lead from water systems is a vital task that can protect public health and the environment. By following this guide, water utilities can comply with the EPA mandate, leveraging ArcGIS Utility Network to streamline the process.
Contact us for more information about how Dudek can support your water utility system mapping and analysis needs.