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Geology, Hydrology, and Groundwater Contamination in the Vicinity of the Central Chemical Facility, Hagerstown, Maryland

Scientific Investigations Report 2022-5011
Prepared in cooperation with the U.S. Environmental Protection Agency
By: , , , , , , , and 
https://doi.org/10.3133/sir20225011

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Abstract

The soil and groundwater at the Central Chemical facility, Hagerstown, Maryland, are contaminated due to the blending and production of pesticides and fertilizers during much of the 20th century. Remedial investigations focus on two operable units (OU) consisting of the surface soils and waste disposal lagoon (OU-1) and the groundwater (OU-2). The contaminants of concern (COC) for groundwater include 41 compounds categorized within the subgroups of volatile organic compounds (VOCs), semi-volatile organic compounds (SVOCs), pesticides, and metals. The purpose of this report is to provide a conceptual site model of the hydrogeology and groundwater contaminant transport at and near the Central Chemical facility. The conceptual model was developed through review, synthesis, and interpretation of the results of hydrogeologic, soil, and other environmental investigations conducted at and in the vicinity of the facility in recent decades and is intended to support plans for environmental remediation of the groundwater in OU-2.

The extent and nature of the groundwater contaminant plume associated with the bedrock was characterized for OU-2 of the site. Lithologic and structural comparisons between shallow soil, weathered rock, and epikarst and deeper competent but bedded, dipping, fractured, and karstic limestones illustrate two connected flow systems—a surficial flow system consisting of the unconsolidated overburden and epikarst and a structurally dominant bedrock flow system below the epikarst. Uncertainties exist regarding the nature and transport of contaminants within the epikarst system particularly within voids and perched epikarst water tables. Karst dissolution features are observed within the site including sinkholes and dissolution voids within wells at the site. Of interest, one well in the northern part of the study area (MW-J-71) appears to have a dissolution void connected to an offsite well (OW-2-115) farther to the north. This connection is supported by groundwater level data and elevated concentrations of total suspended solids (TSS) and chlorobenzene in both wells. The high level of TSS supports the possibility of offsite transport of particle-bound contaminants within the conduit system. Episodically elevated concentrations of COC from different groups also were observed within select wells in the epikarst near the waste disposal lagoon (particularly MW-A-51). The variability observed between different COC within the same well may be the result of additional contaminated source materials unrelated to the disposal lagoon. Storage and episodic transport of contaminated material within the epikarst system has the potential to hinder remediation efforts if not considered in the remedial action.

Suggested Citation

Needham, T.P., Fiore, A.R., Ator, S.W., Raffensperger, J.P., Smith, M.B., Bellmyer, N.M., Dugan, C.M., and Morel, C.J., 2023, Geology, hydrology, and groundwater contamination in the vicinity of Central Chemical facility, Hagerstown, Maryland: U.S. Geological Survey Scientific Investigations Report 2022–5011, 62 p., https://doi.org/10.3133/sir20225011.

ISSN: 2328-0328 (online)

Study Area

Table of Contents

  • Acknowledgments
  • Abstract
  • Introduction
  • Methods
  • Geologic Setting
  • Hydrology
  • Groundwater Contaminants
  • Limitations and Considerations for Future Study
  • Summary
  • Referenced Cited
  • Appendix 1. Reported Well Construction Information, Groundwater Level Measurements, Groundwater Level Drawdown from Aquifer Tests, and Tracer Test Detections, Central Chemical Facility, Hagerstown, Maryland
  • Appendix 2. Concentrations of Contaminants of Concern Observed Over Time in Wells MW-A-51, MW-M-50, MW-B-55, and MW-E-56 at the Central Chemical Facility in Hagerstown, Maryland
  • Appendix 3. Concentrations of Chlorobenzene, 1,2,4-trichlorobenzene, and Technical-Benzene Hexachloride (BHC) in Select Wells at the Central Chemical Facility in Hagerstown, Maryland
  • Appendix 4. Contaminants of Concern for Groundwater Vicinity of the Central Chemical Facility
Publication type Report
Publication Subtype USGS Numbered Series
Title Geology, hydrology, and groundwater contamination in the vicinity of Central Chemical facility, Hagerstown, Maryland
Series title Scientific Investigations Report
Series number 2022-5011
DOI 10.3133/sir20225011
Year Published 2023
Language English
Publisher U.S. Geological Survey
Publisher location Reston, VA
Contributing office(s) Maryland-Delaware-District of Columbia Water Science Center
Description ix, 62 p.
Country United States
State Maryland
City Hagerstown
Other Geospatial Central Chemical Facility
Online Only (Y/N) Y
Additional Online Files (Y/N) N
Google Analytic Metrics Metrics page
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