State Directs Cleanup of Stead Solvent Contamination
State-of-the-art remediation system is now extracting trichloroethene (TCE) —
CARSON CITY- The Nevada Division of Environmental Protection announced that the state-of-the-art equipment used to clean up trichloroethene (TCE) solvent contamination in the shallow groundwater at the Stead Solvent Site is now operational. Following extensive investigation into the potential causes of the spill and scientific sampling to determine the type, extent and depth of contamination, a plan was developed including passive and active remediation — Read This Press Release
Plan for evaluating Groundwater Remediation Progress associated with the Stead Solvent Site Operable Unit 1 (OU 1) —Remedial Action
A plan for evaluating Groundwater Remediation Progress associated with the Stead Solvent Site Operable Unit 1 (OU 1) Remedial Action is now being implemented
By way of background, this groundwater monitoring plan was prepared by American Environmental and Engineering Consultants (AEEC) on behalf of the Appropriate Parties: Airport Authority of Washoe County (AA WC), the City of Reno, the Lear Family Trust, and the Moya Olsen Lear Trust.
The Stead Solvent Site OU 1 is located at and adjacent to the Reno-Stead Airport in Washoe County, Nevada.
View Map — Operable Unit 1
In January 2000 the Appropriate Parties entered into a Consent Decree with the Nevada Division of Environmental Protection (NDEP). A Record of Decision (ROD) for the remediation project (dated July 21, 2000), was subsequently developed to define the objectives and components of the remediation project. Accordingly, the objective of the project is to address trichloroethene (TCE) contamination in the shallow groundwater beneath the site; the following remedial action objectives are being implemented and/or planned:
- Source Area Controls consisting of dual phase extraction (DPE) and soil vapor extraction (SVE) to remove contaminant mass from the source area soils, decrease contaminant migration to downgradient public water supply wells, and expedite site closure.
- Groundwater Hydraulic Containment using groundwater extraction (GWEX) to facilitate hydraulic control and allow hydraulic containment of the dissolved TCE.
- Phytoremediation using appropriate vegetation to intercept the downgradient shallow groundwater plumes.
- Long Term Monitoring to detect and record the impacts of the remediation action components on the extent and levels of groundwater contaminants beneath and downgradient of au 1 and evaluate the effects of Monitored Natural Attenuation.
- Institutional Controls including deed restrictions, water use restrictions, and land use controls.
Frequently Asked Questions
Will the plume migrate off the property?
NDEP has no reason to believe that the Stead shallow ground water plume of solvents could migrate from the property as defined.
How Long is the Plume? Approximately 1500 Feet and it's confined to the shallow soils and Groundwater (40 feet deep). The perimeter shape and size is stable and the highest concentration of TCE is 1500 ppb in the center and 10 ppb at the leading edge.
When was the contamination discovered and who is responsible?
The brief history of the project began in 1989 when Dermody Properties did a Phase II environmental and discovered the contamination. Contamination was caused by multiple sources over an extended period of time. The funding parties bought out the property.
What do we know about the contamination at the site?
We have characterized the site--meaning that scientific sampling has been mapped out to show the type, extent and depth of contamination. At this time, the project is in the best position such that we understand the complex nature of contamination and the remedial plan is about to go online. In addition, the remedial plan consists of monitoring in the vicinity of the plume and this monitoring will continue during remediation.
When will remediation start?
The remediation system has been built and will be in full-scale operation in March 2005.
What is the States role with this project?
Once contamination was discovered, NDEP became involved. A project of this magnitude is typically managed by NDEP's corrective actions bureau. The bureau is responsible for overseeing characterization and cleanup efforts until such time as the site is fully remediated.
What are the specific project time lines for addressing the contamination?
Remediation takes considerable time. This first phase includes a dual phase extraction system to control migration. After about a year of remediation and monitoring, data should support an estimate of the time required for control extraction. Phase II includes Phytoremediation-a biological technology that utilizes the natural properties of plants to hydrologically remediate certain contaminants.
What about the risk to human health from contaminate migration?
If there ever were an indication that the plume was migrating, the flow velocity is slow enough as to allow plenty of time to react and take action to protect human health and the environment.
Who is responsible for operating the remediation systems?
The consulting firm for the funding parties is responsible for maintaining and operating the remediation system as well as providing quarterly monitoring reports.
What about migration of TCE in the Groundwater?
Throughout the characterization process and design and approval of the remediation system, the plume has been stable and monitored during the remedial design phase.