The Formula for an Effective Point-of-Use Filter Distribution Program
Because of the known issues surrounding disturbances and lead level spikes that typically accompany lead service line (LSL) replacements, the U.S. EPA is including a proposed pitcher filter requirement in the impending Lead and Copper Rule (LCR) revisions. Point-of-use filters reduce risk to residents who are experiencing high lead levels at the tap—whether that be from a recent change in corrosion control treatment, a disturbance near a lead service line, or the replacement of a lead service line that can result in a short-term increase in lead levels.
We’ve learned this firsthand while supporting the city of Newark, New Jersey’s optimization of corrosion control and aggressive 30-month Lead Service Line Replacement Program to replace approximately 20,000 LSLs. In 2018, Newark sought to protect its residents from high lead levels by providing free lead testing at the tap and free point-of-use filters while they progressed with changes to corrosion control treatment and replacement of all lead services lines.
Executing a point-of-use filter program is a key component of providing safe drinking water to your community while optimizing your corrosion control and managing LSL replacements. While working with the city of Newark, we learned that implementing a point-of-use program is not a one-size-fits-all solution, since communities are bound to face unique sets of challenges. Here are some key takeaways to implement an effective point-of-use filter program:
Look for NSF 53 and NSF 42 on the label. There are dozens of filters on the market today, so be sure that the filters you’re testing and distributing are certified to remove lead: the label should say NSF 53 (specifically for lead removal ) and NSF 42 for particulate removal. Test various types of filters to determine if any result in lower lead levels in your system. In Newark’s case, faucet filters were found to be more effective at removing lead than pitcher filters.
Test filters on your water quality using a clear testing protocol. Filter certifications are based on a specific water quality developed in a laboratory and not the water quality in your system, so it’s important to test the filters with your unique water quality. If you have an orthophosphate based system, this is especially important, because the certification testing does not currently include a challenge water with orthophosphate chemistry. In developing a testing protocol, there are many things to consider. Are you testing worst case scenarios after extended stagnation periods or random sampling throughout the day? How many samples do you need to feel confident in your results? Are you going to include filters that are not maintained and used properly? What will determine whether or not the filters are “effective” for your system?
Flushing before filtering lowers lead levels further. The lowest lead levels in Newark were achieved when the service line was flushed for at least 5 minutes prior to filtering. In all cases where flushed water was passed through the filter, 100% of the filters reduced lead to levels below the NSF 53 standard. Without flushing first, 97.5% of the filters reduced lead to below the NSF 53 standard when they were properly installed and maintained. We recommend including some flushed samples in your testing protocol.
Keep an eye on particles. Recent studies have shown that orthophosphate can produce slightly negatively charged nano-sized lead-phosphate particles that are challenging for filters to remove. If you find your filters to be less effective than anticipated based on your test results, you can adjust your chemistry to improve the effectiveness of the filters. Utilities can optimize their orthophosphate treatment by adjusting water chemistry to assist in particle aggregation and thereby settling out helping to form a protective layer between the lead pipe and flowing water.
Effective communication is your responsibility. We encourage utilities to provide their own additional installation instructions, available in several languages, that are thorough and easy to understand. Don’t assume that customers will read the instructions and know how to properly use the filters. Keep in regular contact with customers to answer questions, provide on-site assistance, and remind them when filter cartridges need replacing.
Learn more about our filter study we conducted for Newark here.