Influent Metals and Influent Cyanide

at Field's Point are Both Decreasing

Field's Point Wastewater Treatment Facility

Image: Narragansett Bay Commission

Influent Metals at Field's Point

Source: Rhode Island DEM

The influent metals loading data provide a measure of the amount of industrial waste being discharged to the sewer system and are a good indicator of the effectiveness of the Narragansett Bay Commission at controlling and reducing the discharge of toxic pollutants into the sewerage system. The "Influent Metals" data represent an aggregate of the 24 hour composite sample collections for cadmium, chromium, copper, lead, mercury, nickel, silver, and zinc.

Influent Cyanide at Field's Point

Source: Rhode Island DEM

The cyanide contained in the sludge generated at the Field's Point facility has showed an overall downward trend for the period from 1981 through the present. The anomalous spike is due to poor data quality for 1984. Cyanide grab samples are collected thrice daily at the Field's Point Wastewater Treatment Facility; the Narragansett Bay Commission is responsible for the data collection. Since cyanide loadings are attributable solely to industrial sources, the reductions observed are an indication of the NBC source reduction and control efforts.

Cyanide contamination is problematic because the cyanide ion is rapidly absorbed from the gastrointestinal tract and is rapidly converted to thiocyanate by the enzyme rhodanese. Chronic exposure to cyanide include may have deleterious effects on the nervous system and thyroid.

For more information:

http://www.state.ri.us/dem/programs/benviron/water/index.htm
A link to the Rhode Island Department of Environmental Management, Office of Water Resources

http://www.narrabay.com/fac/facilitymain.html
A link to the Narragansett Bay Commission's wastewater treatment facility home page.

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