The U.S. EPA request a referral for civil litigation to the U.S. Department of Justice to initiate against the Estate of Scott Lawson for violations of the Safe Drinking Water Act ( SDWA ), 42 U.S.C. Section 300f et seq., and its implementing regulations at 40 C.F.R. Part 141. Until Lawson died intestate last month, he was the owner and operator of the Oasis Mobile Home Park ( Oasis ) and its public water system ( System ), located on the Torres Martinez Desert Cahuilla Indians Reservation in Riverside County, California. The SDWA violations at issue primarily stem from the System's ongoing failure to treat arsenic from the source water it obtains from groundwater wells and its failure to prevent arsenic from accumulating and concentrating in the distribution lines before being provided to the approximately 1,500 consumers at Oasis. Lawson also failed to comply with two SDWA Emergency Administrative Orders, including the requirement to provide alternative water. These violations are ongoing and present imminent and substantial endangerments to public health. DOJ filed complaint on 8/15/2023.