KITSAP COUNTY - BAINBRIDGE ISLAND DUMP
EFFINGHAM, EFFINGHAM COUNTY, ILLINOIS
No health threat exists for people exposed for 1-5 years to concentrations of contaminants detected in any of the domestic wells sampled to date.
Long-term exposure (DOH assumed 30 years) to the maximum detected vinyl chloride concentration (0.77 µg/l) poses a very low increased cancer risk. At current exposure levels, the risk is even lower. Conversely, the risk would increase if the concentration increased.
Long-term exposure to the most recent lead concentration (2.3 µg/l) in well BOW64 does not pose a health risk. However, because the previous lead concentration in this well was higher, only two rounds of metals analysis were conducted for this well, and this well serves a school, further evaluation of this well is appropriate.
Long-term exposure to the maximum detected arsenic concentration (26.2 µg/l) would pose a low increased cancer risk. However, the concentration dropped to approximately one-third the maximum concentration in a follow-up sample which would pose an even lower risk.
Long-term exposure to the maximum detected manganese concentration does not pose a health risk.
Based on DOH's evaluation of all of the domestic well data provided to date, no apparent public health hazard exists as a result of exposure to contaminants detected in any of the wells.
- Continue quarterly monitoring of domestic wells. Provide DOH with the results
of the quarterly monitoring for review and evaluation.
- Health education should be provided to residents who may still be concerned
about exposures. DOH will work closely with the Bremerton/Kitsap County Health
District to address local concerns.
- Continue to monitor well BOW37 for VOCs to observe that vinyl chloride concentrations
do not increase in subsequent quarters. If vinyl chloride (or other VOCs)
show increasing trends or reach federal Safe Drinking Water Act Maximum Contaminant
Levels (MCLs), exposures should be reduced or eliminated. DOH will continue
to review and evaluate quarterly well monitoring results to determine future
recommendations; or reduce or eliminate exposure to contaminants from this
well (options could include treatment or an alternate water source).
- Well BOW31A should be re-tested by the owner to determine if the arsenic
concentration continues to remain below a level of health concern (DOH can
provide technical assistance and can evaluate test results should the well
owner pursue testing).
- Well BOW64 should be retested for lead (Pb) by the water system to observe
whether the concentration remains below a level of health concern (i.e.- below
EPA's 15 µg/l action level). Washington state drinking water regulatory monitoring
requirements for Group A water systems should be adhered to.
- Ecology's March 1995 and March 1998 letters recommending that the Bremerton/Kitsap County Health District limit its well site approval in the areas identified in the vicinity of the landfill should be adhered to.
Should future public health intervention become necessary, DOH will work with the appropriate agencies to address the possible long-term need for an alternate water source or treatment for wells determined to be at risk.
* Our recommendation to reduce or eliminate exposure to contaminants detected in this well is intended to prevent future exposures to potentially higher VOC concentrations from occurring in the event monitoring is discontinued. As previously indicated, since 1996, when this well was first tested, vinyl chloride levels have dropped in half and monitoring will continue through at least the end of 1999. DOH will continue to assess contaminant trends in this, and other domestic wells being sampled, to determine future recommendations.