Hodgdon Powder Co., Pyrodex Division

Pond Closure Site

Site Background

The Hodgdon Powder Company, Pyrodex Division - Pond Closure Site is located at 1347 S. 2600 Road at the Tri-County Public Airport (TCPA) in rural Delevan, Morris County, Kansas. From 1976 to the present, Hodgdon has primarily manufactured a black powder substitute for muzzle-loading guns. The main constituents of the black powder substitute include potassium perchlorate, potassium nitrate, sulfur, and charcoal. Perchlorate was first detected in groundwater during an Expanded Site Investigation conducted by EPA in 1998 for the TCPA Site (Project Code C5-064-70163). Since that time, perchlorate has emerged as a contaminant of concern.

In September of 2002, Hodgdon signed a Consent Order with KDHE to conduct a Comprehensive Investigation (CI), Corrective Action Study (CAS), Corrective Action Plan (CAP), and Corrective Action (CA). Investigation fieldwork conducted in 2002-2004 identified perchlorate impacts in on-site soils, on- and off-site groundwater (including domestic well impacts), on- and off-site surface water, and on-site sediment. In 2003, a perchlorate biodegradation treatment system was constructed at the facility to treat and destroy perchlorate in plant generated wastewater.

Sampling of domestic water wells has identified widespread groundwater contamination; the extent of the current groundwater plume reaches up to five miles downgradient of the facility, is as much as four miles wide, and affects at least four bedrock aquifers (Herington, Cresswell, Stovall, & Towanda Limestones). Hodgdon provided bottled water to residences with impacted domestic wells until a rural water line was extended to impacted residents in early 2006.

Interim Measures

In response to the Site Investigation findings, Hodgdon implemented several source abatement and interim remedial measures (IRMs) on-site to address and reduce the high levels of perchlorate in soil and shallow groundwater, and further delineate impacts to soil and groundwater. To date, the source abatement, IRMs, and mitigation efforts include: closing five former wastewater holding ponds, replacing a sanitary sewer system, stormwater management and implementation of Bureau of Water compliance programs, removal of an on-site French drain, soil excavation with on-site in-situ bioremediation treatment (2004-present), and on-site in-situ bioremediation injections into two impacted shallow aquifers (Herington injections 2006-present, and Cresswell injections 2016-present).

Routine soil bioremediation sampling, monitoring groundwater at select monitoring and domestic wells, and surface water monitoring continues to track on-site and off-site conditions and performance of IRMs. Performance monitoring conducted to date indicates bioremediation injections have and will continue to effectively reduce perchlorate concentrations in groundwater. In November 2016 KDHE approved a pilot test for bioremediation injections around the former French drain on-site.

A Corrective Action Study (CAS) Report proposing remedial alternatives for on-site soil, source area groundwater, and long-term monitoring of off-site impacts was approved by KDHE in December 2014. In addition, an Assessment and Mitigation Plan (AMP) was approved in January 2015 to provide long-term assessment of potential receptors in the perchlorate impacted areas. KDHE conducted a water well survey in early 2016 to update water well information in the area for future use in the AMP.

Public Comment Period

KDHE is soliciting public comments regarding a proposal to address the environmental contamination. Public comments on the Draft CAD must be submitted to KDHE in writing during the 30-day public comment period from August 27, 2020, through September 28, 2020, to the address listed below. A draft Corrective Action Decision (CAD) document that outlines the proposal for cleanup is available for public review at the KDHE offices in Topeka and at the Herington Public Library at 102 S. Broadway Street in Herington. Appointments to review the documents in Topeka may be made by contacting Courtney Stallman at 785-291-3066. The draft CAD and other pertinent information are also electronically available below. A virtual public meeting may be held upon request.

Public comments can be submitted to: Courtney Stallman, KDHE Bureau of Environmental Remediation, 1000 SW Jackson Street, Suite 410, Topeka, KS 66612 or Courtney Stallman@ks.gov. Comments will be accepted until September 26, 2020.

Additional Information

For additional information, please contact:

KDHE Site Documents