Pensacola News Journal
April 12, 2026
NAVAL AIR STATION PENSACOLA
OPERABLE UNIT 1, SITE 1
SANITARY LANDFILL & ASSOCIATED WETLANDS
The U.S. Navy has proposed a remedial action for Operable Unit 1 (OU 1) Site 1 Sanitary Landfill and Associated Wetlands at Naval Air Station (NAS) Pensacola, Florida. The proposed plan describes the Navy's choice of options for cleaning up the site.
OU 1 consists of the Site 1 Sanitary Landfill and Wetlands 1B, 3, 4D, 15, 18A, and 18B. The Site 1 Sanitary Landfill was used as a disposal site for a variety of solid waste generated on base from the mid-1950s until the landfill was closed in 1976.
The Remedial Investigation (RI) Report documented investigations regarding potential risk to aquatic communities and predatory fish at Site 1. The RI Report Addendum focused on piscivores and intervertebrates. Both the RI Report and Addendum assess risk to human receptors at Site 1 Sanitary Landfill and Wetlands 1B, 3, 4D, 15, 18A, and 18B. The human health risk evaluations at individual wetlands evaluated potential risk to human receptors (maintenance workers and trespassers) based on surface water and sediment exposure. The human health risk evaluation at Site 1 Sanitary Landfill evaluated potential risk to human receptors (maintenance workers and hypothetical residents) based on groundwater exposure. The ecological risk assessments evaluated potential risk to surface water and sediment ecological receptors (plants and benthic invertebrates) and upper trophic level wildlife receptors (fish-eating birds and mammals). The following summarizes the conclusion of the investigations:
Groundwater ? There is potential unacceptable risk to the hypothetical resident exposed to chemicals in groundwater at Site 1. Arsenic, benzene, cadmium, chlorobenzene, iron, and manganese are identified as chemicals of concern (COC) in groundwater and are recommended for continued inclusion in the groundwater monitoring program. Monitored natural attenuation is the selected remedy for groundwater at Site 1, as presented in the 1998 Record of Decision (ROD). This list of COCs represents a change to the 1998 ROD and will be documented in the OU1 ROD/ROD Amendment. No additional evaluation of remedial alternatives is warranted.
Wetland 1B ? No unacceptable risk to human health or ecological receptors based on exposure to sediment and surface water was identified. No Action is recommended.
Wetland 3 ? Unacceptable risk to human health was not identified based on exposure to sediment and surface water. Although iron was identified as a chemical of potential concern in sediment and surface water, no further evaluation of potential risk was conducted. However, iron was detected at concentrations in surface water above the Florida freshwater surface water quality criteria and the freshwater background concentration. It was identified as an ecological COC in surface water.
Wetland 4D ? Unacceptable risk to human health or ecological receptors was not identified based on exposure to sediment and surface water. Iron was detected at concentrations above the Florida marine surface water quality criteria and marine surface water background value, and was identified as an ecological COC in surface water.
Wetland 15 ? Unacceptable risk to human health or ecological receptors was not identified based on exposure to surface water. No Action was recommended as the remedy for surface water. Arsenic, manganese, and the pesticides 4,4' dichlorodiphenyldichloroethane (4,4'-DDD), 4,4' dichlorodiphenyldichloroethene (4,4'-DDE), 4,4' dichlorodiphenyltrichloroethane (4,4'-DDT), and DDx
(sum of 4,4'-DDD, 4,4'-DDE, and 4,4'-DDT) were identified as ecological COCs in sediment based on potential unacceptable risk to benthic invertebrates. Arsenic was identified as a human health COC due to unacceptable risk to maintenance workers exposed to sediment.
Wetland 18A ? Unacceptable risk to human health or ecological receptors was not identified based on exposure to surface water, and no unacceptable risk to human health based on exposure to sediment. No Action was recommended as the remedy for surface water. 4,4'-DDD, 4,4'-DDE, 4,4'-DDT, and DDx were identified as ecological COCs in sediment based on potential unacceptable risk to benthic invertebrates and fish-eating birds.
Wetland 18B ? Unacceptable risk to human health or ecological receptors was not identified based on exposure to surface water. No Action was recommended as the remedy for surface water. 4,4'-DDD, 4,4'-DDE, 4,4'-DDT, and DDx were identified as ecological COCs in sediment based on potential unacceptable risk to benthic invertebrates. Arsenic is identified as a human health COC due to unacceptable risk to maintenance workers exposed to sediment.
The evaluation of remedial alternatives for groundwater at Site 1 Sanitary Landfill was presented in a 1996 Focused Feasibility Study. The selected remedy was monitored natural attenuation. Monitoring of groundwater was implemented in 2000 and is ongoing. Groundwater monitoring ensures that natural attenuation processes are effective and that contaminants do not migrate. The results of the 2024 human health risk evaluation were used to modify the list of COCs recommended for continued inclusion in the monitoring program for groundwater.
Remedies were reviewed for the sediment and surface water contamination at OU 1 wetlands in the 2024 Feasibility Study, as presented below.
Proposed Action for Sediment: Four alternatives for sediment remediation were evaluated for OU 1 Wetlands 15, 18A, and 18B: 1) No Action; 2) Monitored Natural Recovery and Land Use Controls; 3) Sediment Removal, Offsite Disposal, Wetland Restoration, and Restoration Monitoring; and 4) Enhanced Monitored Natural Recovery and Land Use Controls. Sediment alternatives were evaluated separately for each wetland. The preferred remedial alternative for OU 1 Wetlands 15, 18A, and 18B is Sediment Removal, Offsite Disposal, Wetland Restoration, and Restoration Monitoring. The preferred remedial alternative for sediment will be protective, cost-effective, and achieve all federal and state requirements.
Proposed Action for Surface Water: Surface water alternatives were evaluated collectively for Wetlands 3 and 4D. Three alternatives for surface water remediation were evaluated: 1) No Action; 2) Aerobic Surface Flow Constructed Wetland, Monitoring, and Land Use Controls; and 3) Mechanical Aeration, Monitoring, and Land Use Controls. The preferred remedial alternative for OU 1 Wetlands 3 and 4D is Aerobic Surface Flow Constructed Wetland, Monitoring, and Land Use Controls. The proposed surface water alternative involves passively treating groundwater exiting the seep at Wetland 3 by modifying the topography and surface flow to enhance iron removal via precipitation through oxidation and hydrolysis, settling, and sedimentation before the surface water discharges to Wetland 4D. Surface water samples will be collected to track iron concentrations, and land use controls will be implemented to prevent alterations to surface flow or land use in the wetlands. The proposed alternative for surface water will be protective, cost-effective, and achieve all federal and state requirements.
The U.S. Navy is accepting written comments to encourage public input and participation in the selection process. A public meeting may be held in conjunction with the public comment period if a timely request is made. Send written comments postmarked no later than 12 May 2026. Written comments, requests for a public meeting, or requests for information should be directed to:
Mr. Bruce Cummins
Public Affairs Office
Naval Air Station Pensacola
150 Hase Road, Suite A
Pensacola, Florida 32508-1051
Phone: 850-452-4436
For More Information: The Remedial Investigation Report, Remedial Investigation Report Addendum, Feasibility Study Report, and other documents regarding OU 1 Site 1 Sanitary Landfill and Associated Wetlands may be found at https://administrative-records.navfac.navy.mil/?MT64W7KUQ7G47WL.
April 12 2026
LSAR0495635
Miscellaneous Notices