NORTH RAILROAD AVENUE PLUME
On this page:
- What Is Being Done to Clean Up the Site?
- What Is the Current Site Status?
- EPA’s Involvement at the Site
- Sampling and Monitoring
On related pages:
The 58-acre North Railroad Avenue Plume site is a contaminated groundwater plume in Española, New Mexico. The Norge Town laundromat and dry cleaning operation contaminated groundwater with tetrachloroethylene (PCE), trichloroethylene (TCE), cis-1,2-dichloroethylene (DCE) and trans-1,2-DCE. The contaminated groundwater aquifer is the sole-source drinking water aquifer for the City of Espanola, Santa Clara Pueblo and individual water supply wells near the site. The population of Espanola is 10,224 people. The Santa Clara Pueblo has a population of 2,400 people.
The remedy consists of enhanced in-situ bioremediation. The areas targeted for cleanup are the source area and hot spot soils and shallow groundwater contaminated with non-aqueous phase liquid (NAPL) chemicals, a dissolved phase plume in the shallow aquifer, and dissolved-phase plumes in several water-bearing zones in the deep aquifer.
What Is Being Done to Clean Up the Site?
The site is being addressed through federal, state and local actions.
EPA has conducted two five-year reviews of the site’s remedy. These reviews are to determine whether the remedies put in place are protecting public health and the environment, and function as intended by site decision documents. The most recent review concluded that a protectiveness determination of the remedy could not be made until additional information is obtained to assess the potential indoor air vapor intrusion pathway for residential land use. A recommendation was made as part of the review to evaluate potential indoor air vapor intrusion at a few residential structures located in an area where the highest contamination levels in shallow groundwater are found. EPA is planning to collect additional samples to evaluate this potential pathway.
The second five-year review also concluded that there is currently no known human exposure to contaminated ground water. The permitting of new water wells over the area of ground water contamination is currently restricted by the NM Office of State Engineer while remediation is ongoing. Followup actions are needed to achieve long-term protectiveness because the current remedy for the deep aquifer is not expected to achieve the objectives and goals of the remedy.
What Is the Current Site Status?
Operation and maintenance activities for the LTRA are ongoing.
EPA's optimization study indicated that the remedy has been successful at significantly reducing contaminant mass in the soil and shallow ground water, although additional characterization and remediation was recommended to clean up the residual contamination. For the deep aquifer, the remedy has not been effective. Additional characterization of the deep aquifer was recommended to better understand groundwater flow and plume extent. With this information, the merits of continuing with the existing remedy or evaluating the feasibility of another remedial alternative for the deep aquifer can be assessed. Additional characterization of the soil and shallow ground water was initiated in the summer of 2015 as recommended.
EPA completed the second five-year review of the site's remedy. The findings are documented in the Second Five-Year Review Report, dated July 31, 2015.
EPA’s Involvement at the Site
EPA selected the remedy for the site in a Record of Decision signed on September 27, 2001. The remedy consisted of in-place treatment of saturated soil in the Source Area and a Hot Spot near the source area using surfactant or co-solvent treatment, insitu bioremediation of dissolved-phase plumes in the shallow and deep aquifers, soil vapor extraction to treat unsaturated soil in the Source Area. EPA signed an Explanation of Significant Difference in 2008 to change the surfactant/co-solvent treatment to Enhanced Reductive Dechlorination (ERD) and eliminate soil vapor extraction.
The New Mexico Environment Department implemented the remedy through a State Cooperative Agreement with EPA. Construction of the remedy was completed in 2008. A long-term response action (LTRA) began in 2009 following one year of operational and functional performance testing.
In 2014 and 2015, EPA's Office of Superfund Remediation and Technology Innovation conducted an optimization study at the site to evaluate current ERD performance, adequacy of the monitoring program, and cost-effectiveness and efficiency of the remedy. The findings and recommendations of the study are presented in the March 2015 report entitled "Optimization Review Report, Long-Term Response Action Stage, North Railroad Avenue Plume Superfund Site, Espanola, Rio Arriba, New Mexico, EPA Region 6."
Sampling and Monitoring
There is ongoing ground water data collection to support remedy implementation. EPA plans to collect data to evaluate the potential for indoor air vapor intrusion in select residential structures.