Investigation
Groundwater investigations and monitoring are ongoing. The department continues to review and comment on groundwater results to determine next steps in the investigation and cleanup. Investigation of groundwater conditions on- and off-site is continuing, with recent work including installing additional monitoring and extraction wells in the Ozark and Springfield aquifers. For additional information, please review the information under Future Activities.
Regular private drinking water well testing is ongoing. To date, Northrop Grumman and the department have collectively sampled more than 356 domestic-use wells near the former Litton facility. The number of sampled wells continues to increase, as previously unknown wells are discovered and permission is granted by property owners to sample those wells and previously known wells. The most recent domestic well sampling event for which the department has final, validated results, was conducted between mid-December 2021 and mid-January 2022. Northrop Grumman’s submission of the final, validated results for the second quarter 2022 sampling event is pending.
During the first quarter 2022 sampling event, Northrop Grumman collected samples at 123 private well locations, including four locations that were not previously sampled. Of the 123 wells sampled, 100 previously sampled wells, plus the four new wells, did not detect TCE above the reporting limit of 1 microgram per liter, or 1 part per billion (ppb). Samples from 13 of 18 wells with prior TCE detections contained detectable concentrations of TCE or TCE breakdown products. However, all detections for these 18 wells were below the respective TCE maximum contaminant level (MCL) of 5 ppb for drinking water use. One well showed a TCE concentration above the MCL for the first time. A home water treatment system was installed at this residence and groundwater entering and exiting the treatment system was tested. Neither TCE nor TCE breakdown products were reported above the MCL in either sample.
Multiple sampling events have provided a comprehensive data set for private wells in the area and the basis for periodic adjustment of the sampling frequency for those wells. A modified sampling scheme for private wells was developed based on these data and approved by the department in September 2021:
- Wells with TCE concentrations less than 2 ppb will be sampled annually during the second calendar quarter, except that any wells demonstrating an “increasing” or “probably increasing” contamination trend will be sampled semi-annually during the second and fourth calendar quarters, regardless of TCE concentration.
- Wells with TCE concentrations greater than 2 ppb will be sampled semi-annually during the second and fourth calendar quarters.
- Wells with detections of only TCE breakdown products will be sampled annually during the second calendar quarter.
- Wells with no TCE or TCE breakdown products will be sampled on a quarterly or semi-annual rotating basis for a total of one sample per each of the wells every two years. The rotating sampling effort is designed to ensure that non-detect wells within one-quarter mile of wells with positive detections will be sampled during each rotational sampling event.
- Any new wells where detections of TCE and/or TCE breakdown products are present during the initial sampling event will be sampled quarterly for the first year in order to have a full year of data to determine potential concentration variations and to properly place these wells in the correct sampling tier.
- Any new wells that are without detections during the initial sampling event may be placed in the two-year sampling rotation, unless circumstances indicate that more frequent sampling is necessary in specific instances.
Northrop Grumman installed and continues to maintain granular activated carbon treatment systems in homes where wells have exceeded the TCE MCL.
Cleanup
On-site soil cleanup nearing completion. Northrop Grumman completed soil cleanup in two remaining areas. The department approved Northrop Grumman’s soil cleanup completion report for the former Sanitary Lagoon in October 2021. Northrop Grumman submitted a soil cleanup completion report to the department in September 2022 for the former building sub-floor, which is the last remaining soil cleanup area. The department is currently reviewing this report, which is anticipated to be approved in the near future.
Groundwater cleanup continues; system capacity is undergoing expansion. Northrop Grumman continues to pump and treat groundwater from the Springfield-Plateau (shallow) and Ozark (deep) aquifers to remove TCE. During the second calendar quarter 2022, one well was added to the Springfield-Plateau extraction well system, which now consists of four wells. During the second quarter of 2022, approximately 2.2 million gallons of groundwater were extracted, treated and discharged to the Springfield sanitary sewer system from the Springfield-Plateau aquifer, resulting in removing approximately 29 pounds of VOCs from the groundwater. During the second quarter of 2022, approximately 13.4 million gallons of groundwater were extracted from two Ozark aquifer wells, treated and discharged to the Springfield sanitary sewer system from the Ozark aquifer, resulting in removing approximately 33 pounds of VOCs from the groundwater. By the end of the second quarter 2022, approximately 596 pounds of VOCs have been removed from the groundwater since the groundwater extraction systems began operating in June 2019.
Further expansion of the groundwater treatment system for the Springfield-Plateau aquifer is continuing. Treatment building upgrades and regularly scheduled operation, maintenance and monitoring of the groundwater treatment systems is ongoing. The department previously approved Northrop Grumman’s multi-phase extraction (MPE) pilot testing to assess enhanced removal of TCE from the Springfield-Plateau aquifer. Northrop Grumman submitted an MPE pilot test report to the department in May 2022, which the department is currently reviewing. Expanded use of MPE for remediating VOCs is being evaluated.
Mitigation systems in place at Fantastic Caverns. Northrop Grumman and Fantastic Caverns entered into agreements to coordinate ongoing sampling and mitigation efforts at Fantastic Caverns. Fantastic Caverns representatives installed and continue to operate mitigation systems, in coordination with Northrop Grumman. Ongoing air sampling in the caverns confirms the mitigation systems were successfully implemented and that safe air levels are being maintained in the toured portions of the caverns. Northrop Grumman and Fantastic Caverns regularly submit reports to the department, presenting the data collected and documenting ongoing mitigation and testing efforts.
Water Testing & Treatment
What if I'm not in the area of interest, but want to have my well tested myself?
Local Laboratory
Pace Analytical Services LLC, formerly PDC Laboratories Inc., in Springfield takes walk-in requests and provides residents with containers to collect samples, along with an instruction sheet and a chain-of-custody form. The resident will pay up front for the EPA Method 524.2 VOC drinking water analysis, which is approximately $250 plus an additional 8.6% economic fee. The samples are sent to the certified Pace Analytical Services Lab located in Peoria, Illinois. Turnaround time for sample results is about eight business days. Sample results will be sent directly to the individual requesting sampling.
Pace Analytical Services LLC
1805 W. Sunset St.
Springfield, MO 65807
Telephone: 417-864-8924
Contact: Janet Clutters
Email: janet.clutters@pacelabs.com
Other Laboratories
These certified chemical laboratories are also capable of performing analyses of private water samples.
What if I have TCE in my water below the MCL and I want to install a treatment system myself?
The department does not recommend specific types of water treatment systems or a companies that sell water treatment systems; however, the following local companies sell and install whole house water treatment systems:
The National Sanitation Foundation (NSF) tests and certifies water treatment systems for reducing specific contaminants in drinking water:
Related Links
Community Involvement
Community Involvement Plan
The Missouri Department of Natural Resources developed this community involvement plan to facilitate two-way communication between the community surrounding the Litton Systems, Inc. site and the department, and to encourage community involvement in site cleanup decisions. The plan will help the department plan how to effectively communicate with the community and provide opportunities for public participation that will meet community needs and occur as specific milestones are reached related to the ongoing environmental investigation and cleanup for the site.
Health Questionnaire
The Missouri Department of Health and Senior Services (DHSS) sent out a questionnaire in early 2020 to gather input on community concerns and information on how best to communicate with the community. A total of 353 questionnaires were sent out and 94 were returned. Information gathered through the questionnaires will be shared with the community as part of DHSS’s public health consultation, which will evaluate community exposures to TCE in private well water. DHSS is currently preparing the public health consultation, with the release of the public health consultation report anticipated in the next few months.
Public Meetings
Nov. 7, 2019
The Missouri Department of Natural Resources invited the public to an open house and informational meeting about the former Litton Systems Inc. site in Springfield and the former Electro-Pac site in Willard. The meeting was held at the Relics Event Center in Springfield.
March 14, 2019
The Missouri Department of Natural Resources held an informational meeting about the former Litton Systems Inc. site at the Ozark Empire Fairgrounds and Event Center in Springfield.
Future Activities
Activities scheduled for the third quarter of 2022 and beyond include:
- Continue extracting and treating groundwater from the Springfield Plateau and Ozark aquifers, and discharge treated groundwater to the Springfield sanitary sewer system
- Performing regularly scheduled operation, maintenance and monitoring for the Springfield Plateau and Ozark aquifer treatment systems
- Performing regularly scheduled maintenance and sampling of private well treatment systems
- Performing regularly scheduled sampling and analysis of groundwater from private wells and site-specific monitoring wells
- Continue evaluating the Springfield Plateau aquifer contamination through installing additional exploratory borings and groundwater grab sampling
- Collecting and analyzing samples from several springs located in proximity to the site
- Removing sediment and collecting and analyzing groundwater samples from the lower portion of the MWO-09 borehole, located on the Springfield Branson National Airport property
- Submitting routine reports for ongoing activities
Northrop Grumman continues working toward developing a final remedy for the groundwater contamination. Ongoing investigations, including continued sampling and analysis of groundwater from private wells, expanding the Springfield Plateau and Ozark aquifer treatment systems and considering additional, potentially viable treatment technologies are integral to this strategy. Northrop Grumman will continue discussions with the department as they collect information and propose actions to determine the appropriate next steps in working towards a final remedy.
