NPL Site Narrative for Mililani Wells
Island of Oahu, Hawaii
Federal Register Notice: October 15, 1984
Conditions at proposal (October 15, 1984): The Mililani Wells Site consists of six drinking water wells that are owned and operated by the City and County of Honolulu. The wells are located on the lower Schofield Plateau in the County of Honolulu, Island of Oahu, Hawaii. They are contaminated with dibromochloropropane (DBCP) and trichloropropane (TCP), according to tests conducted by the Hawaii Department of Health and other government agencies. Three of the wells are presently not being used. The Mililani wells are part of a distribution system that provides drinking water to about 19,500 people.
There are several well sites with similar contamination problems located in the Schofield Plateau/Ewa Plain area of Oahu. The City and County of Honolulu Board of Water Supply has conducted pilot tests on methods for decontaminating the water in the area and has had success in removing DBCP and TCP with granulated activated carbon and with aeration towers.
Status (January 1986): EPA received numerous comments on the six sites in Hawaii, which were the first sites proposed for the NPL on the basis of contamination that appears to originate entirely from the application of pesticides registered under the Federal Insecticide, Fungicide, and Rodenticide Act (FIFRA). EPA is continuing to evaluate these sites in the context of an overall policy with respect to sites at which contamination results from the application of FIFRA-registered pesticides. Hence, EPA is continuing to propose the sites for the NPL.
The developer of Mililani Town has awarded a contract to build a granular activated carbon treatment plant at the wells. The plant will be designed to remove the pesticides from the water prior to distribution. The plant is complete and is scheduled to be operational in March 1986.
Status (February 11, 1991): The treatment plant has been operating since March 1986.
EPA has decided not to place this site on the NPL at this time because it is in the process of developing a general strategy for addressing contamination from agricultural chemicals in ground water under FIFRA.
For more information about the hazardous substances identified in this narrative summary, including general information regarding the effects of exposure to these substances on human health, please see the Agency for Toxic Substances and Disease Registry (ATSDR) ToxFAQs. ATSDR ToxFAQs can be found on the Internet at ATSDR - ToxFAQs (http://www.atsdr.cdc.gov/toxfaqs/index.asp) or by telephone at 1-888-42-ATSDR or 1-888-422-8737.