Using silicates to lower lead levels in drinking water

Journal Article · Thu Sep 01 00:00:00 EDT 1994 · Public Works; (United States)

OSTI ID:7144593

York is a small resort town on the coast of Maine, near the New Hampshire border. The town's population of 5,000 usually doubles during the summer tourist season. Like many small water systems in New England, its soft, moderately alkaline water corrodes its unlined, cast-iron pipe distribution system, picking up significant quantities of iron along the way. Customers served by these lines have complained about the red water. York Water District officials hoped that a new 4-mgd treatment facility brought into service in spring 1990 would alleviate the red water problems, but they were also considering ways to address the requirements of the Lead and Copper Rule from the EPA promulgated in 1991. With the assistance of their consulting engineering firm, York Water District officials evaluated treatment strategies and decided against using polyphosphates to control lead and copper because of their ability to complex with the metals, possibly causing an increase in concentration. The officials eventually chose sodium silicates to lower the iron, lead, and copper levels in the system. Several utilities in Maine had reported using sodium silicate as a common strategy for red water problems. In addition, sodium silicate was favored because it reacts with metal for form a barrier to corrosion. York Water District, with assistance from its consultant, designed an 18-month program to add sodium silicates to its system, track metal concentrations, and monitor red water complaints. The district prepared a report for the EPA, covering data collected over the first 12 months of the program -- essentially calendar year 1991. According to Michael R. Schock, research chemist with the EPA's Drinking Water Research Division in Cincinnati, the agency is anxious to obtain as much quantitative information as possible on using sodium silicate for pH and/or corrosion control. This article describes the monitoring system, water treatment and study results.

• OSTI ID: 7144593
• Journal Information: Public Works; (United States), Vol. 125:10; ISSN 0033-3840
• Country of Publication: United States
• Language: English

Related Subjects

54 ENVIRONMENTAL SCIENCES
32 ENERGY CONSERVATION, CONSUMPTION, AND UTILIZATION
DRINKING WATER
WATER POLLUTION CONTROL
LEAD
WATER POLLUTION MONITORS
WATER TREATMENT PLANTS
CONTROL
ELEMENTS
HYDROGEN COMPOUNDS
MEASURING INSTRUMENTS
METALS
MONITORS
OXYGEN COMPOUNDS
POLLUTION CONTROL
WATER
540320* - Environment
Aquatic- Chemicals Monitoring & Transport- (1990-)
320603 - Energy Conservation
Consumption
& Utilization- Municipalities & Community Systems- Public Utilities- (1980-)