Control of Lead in Drinking Water
ER-199505
Objectives of the Demonstration
In-line water and oil filters and heat exchanger
Impurities are introduced into drinking water through corrosion in water mains. Water that contains heavy metals such as lead may fail to comply with the requirements of the Safe Drinking Water Act and other regulations. The usual remedy for this situation at U.S. Department of Defense (DoD) facilities is to replace the corroded pipes or to use bottled drinking water. This project validated an alternative remedy with the in-place application of a chemically resistant, non-toxic epoxy coating developed by the Naval Research Laboratory as an interior pipe lining to prevent leaching of metal impurities.
Demonstration Results
Compressors were used to blow hot, dry air and abrasive garnet grit through the drinking water distribution systems to remove rust and other contaminants. Hot, compressed air was then used to deposit a two-component epoxy coating on the interior of the pipes. Subsequent hardening of the coating in a stream of hot air took approximately 20 minutes. The distribution systems were then flushed with water and returned to service within 72 hours. Sampling and testing of the distribution systems before and months after installation showed that lead remained below Environmental Protection Agency (EPA) drinking water standards. Thus, the method was effective in preventing the leaching of lead.
Implementation Issues
This fast, innovative, in-situ lining technique will allow the DoD to comply with Federal regulations and cost-effectively rehabilitate drinking water distribution systems aboard ships and at shore facilities around the world. Installation costs were estimated at $75 per linear foot, and typical savings when compared to pipe replacement were approximately $100,000 for a two-story, 40-unit apartment building.
The system causes minimum disruption to facilities or their occupants, is suitable for pipes inside buildings and underground, and may be used on pipes as long as 1,000 feet despite numerous bends or varying pipe diameters. It is approved by NSF International, the sole firm authorized by the EPA to test and approve materials for contact with drinking water. To eliminate interference with the coating process and to prevent lining failure, residual rust must be completely removed prior to application. Once properly installed, the lining requires no maintenance and has an expected lifetime of 30 years based on previous sanitation applications in aircraft carriers. (Project Completed - 1997)
Project Documents
Points of Contact
Principal Investigator
Dr. Robert Brady
Naval Research Laboratory
Phone: 202-767-2268
Fax: 202-767-0594
Project Documents
Document Types
- Fact Sheet - Brief project summary with links to related documents and points of contact.
- Final Report - Comprehensive report for every completed SERDP and ESTCP project that contains all technical results.
- Cost & Performance Report - Overview of ESTCP demonstration activities, results, and conclusions, standardized to facilitate implementation decisions.
- Technical Report - Additional interim reports, laboratory reports, demonstration reports, and technology survey reports.
- Guidance - Instructional information on technical topics such as protocols and user’s guides.
- Workshop Report - Summary of workshop discussion and findings.
- Multimedia - On demand videos, animations, and webcasts highlighting featured initiatives or technologies.
- Model/Software - Computer programs and applications available for download.
- Database - Digitally organized collection of data available to search and access.