• 2020 System Operation and Remedial Action Progress
• 2019 Griggs-Walnut Annual Report Technical Publication
• 2019 Griggs and Walnut Ground Water Plume Superfund Site Status Update (9-25-2019)
• 2018 Griggs-Walnut Annual Report Technical Publication
• 2016 Griggs-Walnut Annual Report Technical Publication (Updated 11-14-2017)
• 2014-2015 Griggs-Walnut Annual Report Technical Publication
• 2013-2014 Griggs-Walnut Annual Report Technical Publication
• 2012-2013 Griggs-Walnut Annual Report Technical Publication

• Modified Administrative Order for Remedial Action
• Statement of Work, Appendix C

Other Potentially Responsible Parties Acknowledged by EPA

• National Guard Bureau Notice
• New Mexico Armory Board Notice

Finding of No Significant Impact

• Finding of No Significant Impact

Final Remedial Design Report

• Final Remedial Design Report

Remedial Action Supporting Documents

• Preliminary Engineering Report
• Draft Environmental Information Document

Unilateral Administrative Order for Design (Final)

In January of 2010, Doña Ana County and the City of Las Cruces entered into a Unilateral Administrative Order to complete the design of the treatment facility. In March of 2010, EPA approved the Design Work Plan from the Supervising Contractor, Daniel B. Stephens of Albuquerque New Mexico.

• EPA’s Draft Unilateral Administrative Order for Remedial Design and Remedial Action
• Griggs-Walnut Remedial Design Work Plan - March, 2, 2010

EPA has issued a substantially complete Statement of Work for the Griggs and Walnut groundwater plume site. This document will allow the City of Las Cruces and Doña Ana County to commence the procurement process.

Download Statement of Work

EPA’s Record of Decision

EPA issued the Record of Decision in June 0f 2007. The New Mexico Environmental Department, The City of Las Cruces, and The County of Donna Ana concur with the Record of Decision. The City and County now intend to assume responsibility to implement the selected remedy.

Record of Decision (Complete Document) (PDF)

By Section

• Declaration & Decision Summary - Sections 1 to 5 (PDF)
• Decision Summary - Sections 6 to 14 (PDF)
• Responsiveness Summary (PDF)
• Appendix C & D (PDF)

EPA in collaboration with the City of Las Cruces and the County of Doña Ana developed a recommended approach for removing the contamination at the Superfund Site. It is called the Proposed Plan. It has been developed based on the information from the Remedial Investigation and the Feasibility Study and with input from the New Mexico Environmental Department.

The Proposed Plan - Updated December 2006

Site Location

The GWP Site is located in the City of Las Cruces, Dona Ana County, New Mexico. North Solano Avenue to the west; just past I-25 to the east; East Hadley Avenue to the north; and East Griggs Avenue to the south approximately bound the GWP Site. The approximate area of the GWP Site is 0.5 miles by 1.8 miles. (See Map of Area and Estimate of Concentration)

Griggs & Walnut Groundwater Plume Site Map

Public Health Issues

The Agency for Toxic Substances and Disease Registry (ATSDR) is the Federal agency created under the Superfund Act that is charged with taking responsive public health actions to prevent harmful exposures and disease related to toxic substances.

The ATSDR works in close collaboration with local, state and other federal agencies, with tribal governments, local communities and local health care providers. The goal of ATSDR is to help prevent or reduce the harmful effects of exposure to hazardous substances on human health.

The ATSDR finalized a Public Health Assessment (PHA) in February 2005 that reviewed available health-related data for the Griggs and Walnut site. The PHA indicates concentrations of PCE are below levels expected to cause adverse health effects. ATSDR has concluded that the Griggs and Walnut Site presents no apparent public health hazard for past or current PCE exposure resulting from the municipal water supply. The ATSDR report is available at:

Thomas Branigan Memorial Library
200 East Picacho Avenue
Las Cruces, NM 88001
(575) 528-4000

The ATSDR Public Health Assessment is available to download. The results of this report are summarized in the (Proposed Plan).

Remedial Investigation & Feasibility Study

• Remedial Investigation
• Feasibility Study

Preliminary Studies by the Joint Superfund Project

• Phase I – Evaluation of Treatment Technologies
• Phase II – Conceptual Design for PCE Treatment
• Phase II – Conceptual Design for Uranium Treatment

Source of Contamination

The source areas of contamination to the ground water have been identified as historical releases that occurred on City and County property. Given the multiple land use activities that have occurred over time on the properties, the releases were most likely associated with either maintenance activities, or illegal dumping by unidentified parties.