From the email -
I learned a few more bits of information regarding the failure(s) at the MRTF. Specifically, this deals with the legal relationships between EPA, the , the County, the Participating Companies (PCs) and the AZ American Water Co.
EPA and the signed a Consent Decree (CD) with the PCs, not the water company. The PCs are responsible for extracting and treating groundwater contaminated with TCE. The PCs chose the water company to do this, but the PCs are not responsible for the operation & maintenance of the plant. EPA has no direct authority over the water company under the CD.
The AZ American Water Co. is subject to the Safe Drinking Water Act (SDWA) which EPA has delegated to the State and the State has delegated to the County. All three entities (fed, state, county) may take enforcement action against the water company. The PCs are not subject to the SDWA.
She went on to explain that the affected treatment facility (Miller Road Treatment Facility, or MRTF) has been shut down until further notice while an investigation is conducted. It will not be brought back online until the various regulatory agencies involved (federal, state, and local) believe that the plant will be operated safely.
In addition, depending on the outcome of the investigation, the operator, Arizona American Water, and the "PCs", or participating companies (Motorola, Siemans, and GlaxoSmithKline) could face financial penalties arising from the incident.
Note: The PCs are the companies responsible for the groundwater contamination, either because they dumped the solvents improperly, or they acquired the companies that did.