The safety and security of major infrastructure systems in the United States, including drinking
water distribution systems, has recently come under reassessment. Several chemical and
biological agents have been identified that could constitute a credible threat against a water
distribution system. In order to protect drinking water supplies, the U.S. Environmental
Protection Agency (USEPA) initiated a program in 2003 to investigate real time sensors that may be
used to trigger a contamination event and support early warning systems (EWS) within a water
distribution system. These sensors monitor for standard drinking water parameters such as pH,
free chlorine, oxygen reduction potential, dissolved oxygen, specific conductance, turbidity, total
organic carbon, chloride, ammonia, and nitrate. The research was conducted on a recirculating
pipe loop at the USEPA's Test and Evaluation Facility in Cincinnati, Ohio. The experimental results
indicate that the parameters of free and total chlorine, total organic carbon (TOC), Oxygen
Reduction Potential (ORP), specific conductance and chloride were consistently able to indicate
a change in water quality due to injections of various contaminants into the pipe loop. Research
is also being conducted to determine the minimum contaminant dose required to trigger a sensor
alarm. Contaminants tested to date include secondary effluent from a waste water treatment
plant, potassium ferricyanide, arsenic trioxide, nicotine, aldicarb, E. coli K-12 strain with growth
media, insecticide containing malathion, and a herbicide containing glyphosate. Future testing
with chemical and biological warfare agents has been initiated.
Includes 5 references, tables, figures.
| Edition : | Vol. - No. |
| File Size : | 1
file
, 430 KB |
| Note : | This product is unavailable in Ukraine, Russia, Belarus |
| Number of Pages : | 16 |
| Published : | 04/10/2005 |
