(a/k/a DRY BRIDGE ROAD LANDFILL)
NORTH KINGSTOWN, WASHINGTON COUNTY, RHODE ISLAND
In March 1998, four surface soil (1-3 inches deep) samples were collected by RIDEM throughout the back yard of the above mentioned house, 25 feet from the landfill property line, and analyzed for metals and asbestos. A fifth sub-surface soil sample (exceeding 1 foot) was collected from the front yard of the house and analyzed to determine the background soil characteristics (or the "normal" composition of the soil). The following table provides the soil characterization analyses results obtained from RIDEM (5):
|Chemical||Concentration Range (ppm)||Background Concentration (ppm)||Comparison Value (ppm)||Source|
EMEG = Environmental Media Evaluation Guide
RMEG = Reference Dose Media Evaluation Guide
RBC = Risk-Based Comparison Guide
ppm = parts per million
child = levels that are safe for children
residential = levels that are safe for residential areas
ND = Not Detected
The chemicals found in the residential soil are below ATSDR's and the Environmental Protection Agency's (EPA) screening values1. While there is no national soil standard (or screening value) for lead, EPA's Office of Solid Waste recommends that soil lead levels less than 400 parts per million (ppm) are considered safe for residential use >(6). The lead levels found in the residential soil next to Dry Bridge Road Landfill fall within Rhode Island Department of Health "Lead-Safe" Standards for soil (7). Asbestos was allegedly disposed in the Dry Bridge Road Landfill, however, analysis of residential soil did not detect asbestos fibers in surface or sub-surface soils. Adequate landfill soil covering practices could have minimized the air-borne distribution of asbestos fibers to residential areas. Based on these soil sampling results, ATSDR concludes human exposure to residential soils in the past, present, and future do NOT present a Public Health Hazard.
Potentially contaminated airborne dust from the Dry Bridge Road Landfill may have settled in off-site areas where residents could come into contact with the accumulated dust particles. The most likely point of exposure through this pathway is a single house on the southern perimeter of the landfill. This house is currently inhabited by two adults and was previously inhabited for 10 years (1985-1995) by a family of four, which consisted of three adults and one child. The child lived in the house for four years. The next closest residences that are downwind of the site are in a small subdivision that was built in the early 1990s about ¼-mile east of the landfill. However, human exposure is not expected to be occurring since trespassers are currently being restricted via fencing and 24 hour security.
ATSDR CHILD HEALTH INITIATIVE
During the evaluation of soil contaminant levels at the residence bordering Dry Bridge Road Landfill, ATSDR used the Environmental Media Evaluation Guidelines (EMEG) for children, who are considered the most sensitive segment of the population. ATSDR did not identify any chemical contaminants in residential soil at levels of health concern to children.
1For a complete description of ATSDR's health screening values, refer to Appendix A