Water Remedial Action Plan
The site conditions initially encountered by the AltEn Facility Response Group (FRG) in early 2021 were challenging due to the presence of more than 180 million gallons of untreated process wastewater held in three lagoons and an emergency pond that risked overtopping, along with two anaerobic digesters and other tanks that presented risks of failure.
The FRG has diligently worked to stabilize the lagoons on site, treat and remove millions of gallons of process water from the site, and helped ensure the safety of the community and its groundwater.
Lagoon and Groundwater Monitoring
NDEE testing has consistently shown no evidence of impacts to local drinking water. The AltEn site is downgradient from the Village of Mead’s public water supply, and there has been no indication in continued monitoring or sampling that suggests the presence of pesticides in the water supply.
To date the FRG has completed the following water remedial activities:
- Conducted regular inspections of the waste-water lagoons, including daily monitoring and weekly groundwater well monitoring.
- Constructed a new, lined pond system that provides an additional 50 million gallons of storage capacity.
- Refurbished the emergency pond to allow for the digesters to be safely drained in advance of freezing, winter conditions.
- Removed excess water from the lagoons to create safe freeboard conditions.
- Treated more than 49 million gallons of wastewater, 29.4 million gallons of which have been applied to nearby farms as a beneficial nutrient source.
The FRG submitted Water RAP recommendations for NDEE approval on September 12, 2022 and worked with the agency on their proposed updates to that plan, resubmitting a Revised RAP on October 14, 2022. On November 10, 2022, NDEE announced that it is proposing approval of the Revised Water RAP and solicited written comments that are due by December 13, 2022. NDEE is hosting a public information session and hearing on the RAP on December 14, 2022. The Water RAP recommends:
• Treating the untreated water and the stormwater that accumulates within the lagoons and pond during the remedial action period.
• Managing the treated water through land application.
The proposed remedial action contained in the Water RAP includes a summary of alternatives that were considered, the proposed remedial action, potential pre-design investigations, and the anticipated schedule.
Latest Water RAP Updates
Frequently Asked Questions – Water
The public hearing about the water RAP is taking place on December 14, 2022. The details for this and all upcoming community events are available on the events page.
NDEE testing of groundwater monitoring wells has consistently shown no evidence of impacts to local drinking water. The AltEn site is downgradient from the Village of Mead’s public water supply, and there has been no indication in continued monitoring or sampling that suggests the presence of pesticides above EPA drinking water standards in the water supply.
When the FRG entered into the Voluntary Cleanup Program (VCP) to address the situation at AltEn in early 2021, it had to address a number of obstacles and worked deliberately and effectively to mitigate egregious problems created by AltEn. Rebuilding a new lagoon system was time and labor intensive, as was relocating tons of wet cake into a single location. The FRG then covered the wet cake for waste containment, odor control, and to prevent contact between the wet cake and any precipitation, precenting the generation of additional contaminated stormwater, which took months of planning, testing, construction and mobilization.
While completing the work that stabilized the site the FRG concurrently treated and removed millions of gallons of process water, developed a Remedial Action Plan for water stored at the site and is developing a RAP for the onsite solids. . The FRG is working diligently to conduct extensive testing on the remaining site materials and evaluating various remediation methods in order to recommend the best method to protect human health and the environment.
The recommendations put forth in these RAPs have been vetted and used to remediate sites across the country. The FRG will be recommending approaches that are backed by strong scientific consensus with real track records of success, that prioritize the safety of the community and environment. Ongoing maintenance and monitoring will ensure the long-term success of remediation at the AltEn site.
