Military Base Drainage

One installation, several drainage duties

A motor pool, aircraft apron, fuel storage area, dining facility and family housing neighborhood can share an installation while needing different collection, treatment and discharge systems. Begin with a zone plan showing water sources, traffic, low points and destinations. A drain suitable for a housing driveway is not automatically suitable for a tactical vehicle crossing; an apron drain is not automatically suitable for hangar firewater.

For U.S. projects, establish the applicable criteria and contract editions before selecting products. The WBDG UFC library identifies current documents and directs users to UFC 1-200-01 for project applicability. Relevant subjects include UFC 3-201-01 civil engineering, UFC 3-240-01 wastewater, UFC 4-214-03 central vehicle wash facilities and UFC 4-211-01 aircraft maintenance hangars. Apply the appropriate Service requirements and installation supplements. UFGS documents are guide specifications to be edited into project requirements; UFGS 33 40 00 Stormwater Utilities is one example, not a universal specification for every drain on post.

Identify each system's permit and responsible operator. An installation can have different stormwater, wastewater, spill-control and tenant obligations; do not assume one fence line means one permit or approval. Record utility ownership, receiving-system limits and controlled-site delivery requirements early.

Separate collection from treatment and containment

Paved surface runoff. A channel or trench drain intercepts sheet flow across a line; a catch basin collects at a defined low point. Regrading, swales, curb inlets, detention or approved infiltration may address the site more effectively than adding a trench. Confirm bypass routes so an obstructed inlet does not redirect water through a doorway or into a fuel containment area.

Soil and landscape water. Subsurface drainage addresses water within soil, while surface grading addresses ponding above it. NDS EZflow is a gravel-free French-drain option to investigate where soil, filtration, cover and outlet conditions suit it; confirm the required configuration and supply. Do not infiltrate wash water or runoff from contaminated soil simply because a field is nearby.

Roofs and buildings. Keep roof drainage, required emergency overflow and membrane connections in the building design. Include roof flow in an apron calculation only if it actually discharges there. Sanitary floor drains need the specified traps, venting, trap-seal protection, waterproofing connections and approved wastewater destination. A landscape basin or exterior trench does not replace these details.

Oily or process water. Drainage Connect offers ACO Oleopator P and Spill Control separators for evaluation. Separate free-oil removal from spill storage, dissolved-contaminant treatment and water reuse. EPA fleet-maintenance guidance explains why emulsifying detergents and excessive flow can undermine oil-water separation. A separator label does not authorize storm-drain or sanitary-sewer discharge.

Calculate both peak flow and stored volume

Illustrative rainfall check: 1,000 square feet receiving one inch of rain represents about 623 gallons before infiltration and other losses. A hypothetical 200 × 120-foot impermeable apron therefore receives about 14,960 gallons per inch. Volume is not peak flow: using a screening runoff coefficient of 1.0 and a uniform design intensity of 2 inches per hour gives about 499 gpm. Select the actual local design storm, duration, runoff coefficients and tributary areas for the project; use hydrograph routing where detention or a larger catchment warrants it. The Runoff Calculator and runoff method guide can support preliminary checks.

For wash racks, use equipment-provider flow schedules or measurements, including simultaneous wands, arches, underbody jets and dump cycles. Include recycled water returning to collection; fresh-water makeup alone understates that flow. Evaluate rain on exposed pads and adjacent run-on, plus required coincident operating scenarios. Firewater and foam discharges need their own design flow, duration and containment scenario, coordinated with fire protection and environmental staff.

Check inlet capture and bypass, channel conveyance, each outlet connection, downstream pipe losses and receiving water level. Pipe diameter alone does not establish a gpm limit. Use actual internal dimensions, roughness, slope, available head and tailwater in the FHWA HEC-22 drainage methods and manufacturer calculations. Where inflow exceeds conveyance, evaluate additional outlets, larger conveyance or designed storage with a safe overflow route.

Pavement crossfall, channel fall and accessible-route slopes are different constraints. A sloping channel invert does not pull water across a flat slab. Do not assume one minimum velocity will keep every mix of sand, clay and grit suspended. Provide accessible sediment removal and inspect after significant washing, storms and snowmelt. Snow-storage areas need an unobstructed meltwater path and sediment handling; a sump below an outlet is not automatically useful storm detention because it may already hold water or debris.

Select for actual loads and the complete installation

Record maximum loaded wheel and axle loads, tire contact area and type, crossing angle, speed, repetitions, braking and turning. Check the grate, retention, edge rail, channel, concrete support, anchors, joints and subgrade together. EN 1433 uses prescribed load tests and classes; the class number is not a vehicle weight or a promise that the installation tolerates every dynamic load.

NDS letter classes, EN 1433 classes, H-20/HS-25 design references and AASHTO M306 are distinct. Obtain the specified standard and edition, test conditions and matched assembly documentation; do not use a letter match or force conversion as equivalence. See the load recommendation guide and ACO's load-test discussion.

Tracked vehicles: nominal ground pressure does not capture track-shoe contact, edge impact or the lateral forces of a pivot. Route drains away from turning areas where possible and assess the actual crossing with the structural designer and manufacturer. Ductile iron and locking hardware alone do not establish track suitability. Outriggers, trailer landing gear, jack stands and equipment support pads: keep them off drains unless the specific concentrated load and support arrangement are approved. An E600 or F900 label does not resolve these cases.

Aircraft: identify the design aircraft, landing-gear arrangement, wheel loads, tire pressures and operational crossing conditions, including relevant ground support equipment. Require the airfield project's structural and grate-retention criteria. EN F900 or a published aircraft proof-load claim alone is not approval for every aircraft or pavement position. The airport drainage guide and heavy traffic guide provide related selection context.

Plan the drain and destination by zone

Compare product families against the same requirements

Use hydraulic capacity, structural duty, chemistry, maintainability, geometry and documented procurement compliance to compare alternatives. The following are candidates for evaluation, not blanket base-wide approvals. Confirm exact configurations, availability and lead times before purchasing.

Review the actual fuels, lubricants, hydraulic fluids, glycol formulations, deicers and cleaning solutions, including concentration, contact time and discharge temperature. Assess the body, exposed rails, fasteners, seals, sealants and any liner together. A resin, stainless alloy or concrete family name does not establish resistance to every chemical; coordinate freeze-thaw exposure, corrosion protection and any fire-performance requirements with the selected manufacturer.

Federal submittals and domestic-preference requirements

Identify the actual contract clauses and funding program. FAR Buy American construction-material rules concern direct federal construction procurement, with applicable exceptions and trade-agreement provisions. Buy America requirements for assistance programs, including Build America, Buy America (BABA), are distinct. EPA's WIFIA guidance explains both BABA and the separate American Iron and Steel (AIS) requirement for that water-infrastructure program. A base address alone does not make every purchase subject to all three regimes.

• Document the specified assembly. Request drawings, load evidence, hydraulic calculations, material and chemical data, grate-retention details, installation instructions and maintenance requirements for the exact parts.
• Document origin separately. Obtain manufacturer evidence addressing the contract's manufacturing, content or iron/steel process requirements for the supplied components. A U.S. office, broad domestic-product claim or M306 performance statement does not establish procurement compliance. Resolve the applicable FAR/DFARS clauses, exceptions and waivers with the contracting team.
• Compare substitutions explicitly. Show differences in opening, depth, load tests, support, corrosion resistance, discharge and maintenance. Follow the contract's approval process; an online listing or distributor quote is not an or-equal approval.
• Plan receiving and spares. Include gate access, delivery windows, unloading arrangements and any required escort. Record approved replacement grate and fastener part numbers; similar dimensions alone do not establish interchangeability.