The department said the plan calls for excavation of contaminated soil, the installation of soil borings and a monitoring well and the collection of soil and groundwater samples to define the extent of contamination.
The Rio Grande Power Plant uses natural gas and fuel oil to generate electricity. The department said past spills from several above ground storage tanks that hold the fuel oil contaminated soil and groundwater.
After the investigation is done, El Paso Electric will have to submit a cleanup proposal. The public will have an opportunity to comment on that plan and request a hearing or meeting.