South Valley Site

Site History:

southvalley_000Industrial activities during the 1950s and 1960s resulted in contaminated soil and groundwater due to chlorinated solvents and other substances, leading to the closure of 20 private and two municipal water supply wells.

In 2006 and 1998 settlement agreements were reached with several responsible parties, and ONRT received total of almost $5 million for groundwater restoration.

Restoration Activities:

The ONRT has identified two projects for groundwater restoration: the Mountain View Nitrate Plume Restoration Project and the Liquid Waste Groundwater Protection Project. Details about the projects can be found in the Natural Resources Restoration Plan for the South Valley Superfund Site [El Plan de Restauración de Recursos Naturales para el Sitio del Superfondo de South Valley, Albuquerque, Nuevo Mexico].

Mountain View Nitrate Plume Restoration Project [ MAP ]

ONRT is funding the cleanup of groundwater contamination that has existed for over 50 years in the Mountain View area of Albuquerque. The $4.5M restoration project is designed to reduce nitrate concentrations in groundwater close to or below the State groundwater standard by using active and passive remediation technologies. The active phase will use a stepwise remediation process that employs a combination of pump-treat-discharge and enhanced bio-denitrification (EBD) technologies that are designed to reduce nitrate-contaminated groundwater within two hot spots to a concentration of approximately 40 mg/L. Upon completion of the active phase of remediation, natural attenuation will then be used to reduce the remaining nitrate contamination to the State groundwater standard (the passive phase). The ONRT contractor has initiated the design and implementation of various field tests that will result in the final design and construction of the EBD groundwater remediation system. A scale-down version of one of the remediation systems was completed at one of the two hot spots (the southernmost) and became operational in October 2014. This scale-down system was successful in remediating approximately 4.6 million gallons of nitrate-contaminated groundwater by April 2016 at which time the system was shut down and expanded in size to a full-operational system. The re-start of the expanded system occurred in October 2016 and by the end of December 2016, it had treated a total of 5.2 million gallons of contaminated groundwater. A second scale-down remediation system for the other contaminant hot spot (the northernmost) has been under construction since March 2016 and continues to this day. This system, located approximately 4,000 feet north of the other, is expected to be operational by the fall of 2017 and, based on its performance, may also be expanded to speed up the remediation efforts. The New Mexico Environment Department (NMED) is providing some of the technical management and oversight of the project.

  
 
Photos show the enhanced bio-denitrification groundwater remediation system at one of the nitrate hot spots (top photo shows above-ground structures; bottom photos show equipment and controls inside the metal building).

 

Liquid Waste Groundwater Protection Project
ONRT funded the upgrade of household septic systems for qualified indigent homeowners in Sandoval, Socorro and Valencia counties. The goal was to protect groundwater quality by eliminating substandard liquid waste disposal systems. In addition to protection of groundwater, the project eliminated public health and safety hazards associated with illegal cesspools and improperly constructed septic tanks.

Installation of new 1,000-gallon concrete septic tank (2/14/11)

Installation of new 1,000-gallon concrete septic tank (2/14/11)

Installation of plastic infiltrator chambers for the drain field of new septic system (2/14/11)

Installation of plastic infiltrator chambers for the drain field of new septic system (2/14/11)

 

ONRT provided $232,000 for the implementation of this project which included funding for NMED Environmental Health Division’s oversight of the following actions:

  • Proper abandonment of cesspools or other substandard on-site liquid waste disposal systems
  • Installation of on-site disposal systems that meet regulatory standards
  • Connection of a household to a centralized wastewater collection and treatment system if nearby service was available.

Upon completion of the project in 2013, a total of 25 household upgrades were done: 23 residences received new conventional on-site septic systems replacements (septic tanks and drain fields) and 2 residences were connected to nearby municipal sewer lines. In the process, 14 substandard septic tanks and 16 cesspools were properly emptied and abandoned from 24 residences; 1 residence had no disposal system at all.

Additional details about the Liquid Waste Groundwater Protection Project can be found in the Restoration Plan for Groundwater Protection in the Middle Rio Grande Valley.