Paper No. 6-4
Presentation Time: 8:00 AM-12:00 PM
GEOCHEMICAL ANALYSES OF THE HEAVY METAL CONTENT IN THE CLAY/SILT SEDIMENT OF A SMALL STREAM SYSTEM THAT HAS BEEN SUBJECT TO OVERFLOW FROM A SEWAGE TREATMENT PLANT
In Paddock Lake Wisconsin, the local water treatment facility dispatches its overflow into a small stream that then drains into a State-protected swamp. This stream flows for approximately one mile through six residential properties. The water is a result of exceeding the capacity of the facility, mainly due to large rain events and spring thaw, and may be inadequately treated or not treated at all. The overflow has potential to contain heavy metals including: antimony (firearm refuse, batteries, and ceramics), arsenic (treated wood), barium (paint pigment), bismuth (paint, makeup), cadmium (brazing, soldering, electroplated parts), lead (old toys, paint), mercury (thermometers, medicines), nickel (cigarettes, diesel, food waste), tin (rubber), and others. The sources for these heavy metals can be found in the surrounding area, within the stream, and in water runoff that the treatment plant may be discharging. The sources may also not come from the plant itself, but from the residents that live along the stream. Evidence of dumping, garbage disposal, and personal drain tiles are found draining into this stream. The threat of bodily waste, fecal matter, and other household wastes may also be prevalent and pose a health issue.
Seventeen soil samples at fixed intervals (approximately 300 feet) throughout this mile- long stream were taken, 4 were taken at the mouth of the stream, 250 feet from the treatment facility. The samples were processed through a 4 Φ sieve to separate the clay and silt sediment from the bulk material. To discover what resides in the clay and silt sediment, an x-ray (XRF) analyses is conducted. The lead content of organics was measured by XRF from one of the samples that was taken directly from behind a residence; the organic material (fine roots), is lead-free. A coliform test can be performed on dissolved soil samples to indicate if certain types of E. coli, commonly found in fecal matter, are present. The results of the analyses will determine if the material and water that has been pumped into this stream has been treated properly and is safe for the close contact that it has with the surrounding residents.