Atch_6_-_Tooele_Air_Ctr_-_Env_Containment_Infrastructure.pdf

United States Department of the Interior

BUREAU OF LAND MANAGEMENT

Fire and Aviation 3833 S Development Ave

Boise, Idaho 83705-5354

March 2, 2020

State Department of Environmental Quality

RE: Proposed Environmental Containment Infrastructure at SEAT/LAT Bases

This operational description is intended to provide a clear description of the infrastructure to be provided at BLM Single Engine Air Tanker (SEAT) and Large Air Tanker (LAT) Bases. The description is being submitted to assist the understanding for the eventual environmental permitting process.

The BLM operates 30 emergency fire response tanker bases across 13 western states on a seasonal basis during a typical operating period of May through September. The BLM has developed the infrastructure design that is described here through several years of research and working through environmental impacts at various tanker bases across the west served by the BLM. Tanker aircraft contracted by BLM can carry 400‐13,000 gallons of fire retardant per load, depending on the size of the aircraft.

Tanker aircraft utilize liquid concentrate Perimeter Solutions LC‐95A fire retardant, which is stored in concentrated liquid form in tanks at each site. Before loaded on an aircraft the retardant is diluted to a

5.5:1 water to retardant ratio. The chemicals to note in this material are nitrogen and two RCRA heavy metals, all of which are below the hazardous materials thresholds in the diluted form uses for fire suppression. (NOTE: there is no trace of PFAS chemical in this fire‐retardant source).

The tanker bases are designed for construction with a “closed system.” This is achieved using an evaporation pond to capture ALL stormwater, wash water, and any accidental release of retardant at the loading pits. Drainage is directed to the evaporation pond through a trench drain. The liquid concentrate retardant tank, mix tank (diluted retardant), and all transfer pumps are located in a secondary containment area sized to hold 110% of the largest tank volume plus an appropriate rain event. The design also includes a retardant transfer pad to capture spills during retardant deliveries. The secondary containment area and the transfer pad do not have drains or piping penetrating them, hence, all precautions for prevention of any environmental release have been accounted for in the tanker base design. See General SEAT/Tanker Base Layout at the end of this document.

The evaporation pond will be sized to meet the demands of the operations, which typically occur from

May through September. A three‐way diversion valve is used to direct flow to the evaporation pond while the base is operating and to the host airports storm drainage system when the base is not operating. As outlined in the BLM’s tanker base Standard Operating Procedures (SOP) only specific personnel have authority to control the valve. All BLM tanker bases follow Best Management Practices

(BMP) and have Stormwater Pollution Prevention Plans (SWPPP). All BLM bases are inspected on a regular cycle for preparedness and environmental compliance through the Compliance Assessment for

Safety Health and Environment (CAHSE) inspection program and per Fire Leadership Policy.

At the end of the fire season, the BMP in the SOP required by our Fire Leadership, is a complete wash down of the loading pit area and trench drain with a pressure washer. This washdown will drain to the evaporation pond. In addition, personnel will secure all tanks within the secondary containment area, secure miscellaneous chemicals (such as WD‐40, general lubricants) and small fuel cans in a flammable storage cabinet. After shut down procedures are complete, appropriate BLM personnel will operate the three‐way diversion valve to direct flow to the host airport’s storm drainage system, as would be permissible under the host airport’s Stormwater Permit.

BLM’s SWPPP will be provided to the host airport for inclusion under their permit and within their

Stormwater Pollution Prevention Plan. BLM will have a Memorandum of Understanding (MOU) in place with the host airport leadership that regular communication would occur around site inspections, sampling and visual inspections to ensure no impact from the BLM operating area occurs.

See Typical Tanker Base Layout on next page.