CLDJ-321 Install 3 New Groundwater Monitoring Wells

CURRENT SITUATION: Off-base dumping of trash, raw sewage, and waste oil and open burning of trash by the Djiboutians within the Ambouli Oued and within 0.2 miles of the western fence-line of CLDJ has the potential to contaminate the source water for the base. A “Groundwater under the direct influence (GWUDI) of surface water” designation by the WQOC for CLDJ links the Ambouli Oued surface water quality directly with the CLDJ groundwater source. The current drinking water wells should not be used to assess potential pollutants in groundwater and migration of polluted groundwater should be conducted upgradient of the source water for the base. REQUIREMENTS: Install Three 50 meter deep "Sentry" groundwater wells are proposed to be drilled along the western fence line of CLDJ between the dump sites and the source area for the base drinking water wells. The monitoring wells will be constructed using a mud-rotary drill rig, constructed according to military well construction standards, cleaned and developed as needed, and constructed flush to the land surface and with traffic-rated well boxes. MISSION IMPACT: Pollutants such as metals, volatile organic compounds (VOCs), polynuclear aromatic hydrocarbons (PAHs), nitrate/nitrite, and pathogens can affect the drinking water. Contaminants can also affect treatment of the water and can:  decrease the consumer confidence in the quality of the provided drinking water (Must add contaminated source water narrative to annual CLDJ Consumer Confidence Report), directly affect the integrity of the Reverse Osmosis (RO) membranes, contaminate the treatment train and RO membrane, bypass the RO system and directly contaminate drinking water, cause contaminants to be concentrated in the brine discharge (polluting surface waters), cause the spread of contamination in ground water, and trigger additional treatment methods.