Aluminum Flat Tank Covers for Wastewater Treatment
| FLAT COVERS – F.R.P. (click here for details/specs) section 13300 | FLAT COVERS – ALUMINUM (click here for details/specs) section 05522 |
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| Pultruded F.R.P. Frankfort, IL | Extruded Alum. River Oaks, FL |
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| Pultruded F.R.P. Wierton, WV | Extruded Alum. Home Glen, IL |
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| Pultruded F.R.P. Wierton, WV | Formed Alum. Pleasanton, KS |
Installed projects
RPS aluminum flat covers installed at municipal and industrial wastewater facilities across North America.
Municipal wastewater treatment facilities — North America
RPS Engineering aluminum flat tank covers are custom-fabricated for wastewater treatment tanks of all shapes and sizes. Built from 6005A-T5 alloy with interlocking plank profiles, these covers provide odor containment, operator safety, and long-term durability in the corrosive environments common to municipal and industrial wastewater facilities.
Every flat cover is engineered to your tank’s exact dimensions — not adapted from a standard size. RPS field-measures before production to ensure a proper fit every time.
Applications
RPS aluminum flat covers are used across every stage of the wastewater treatment process:
| Tank type | Typical cover approach |
|---|---|
| Aeration tanks | 5×6 M/F interlocking planks on structural framing; 16–36″ hatches as needed |
| Equalization basins | Often rectangular — confirm L×W and all in-tank equipment before ordering |
| Wet wells & pump stations | Airtight with stub-ups for suction pipes; large removable panels for pump access |
| Sludge holding tanks | Odor containment priority; custom fit around decant equipment |
| Headworks & channel areas | 2×7 low-profile planks for tight clearances over bar screens and grinders |
| Flow splitter boxes | Custom geometry; weldments common for irregular shapes |
Plank profiles
RPS manufactures two primary aluminum plank profiles for flat covers. Choosing the right profile depends on span length and load requirements.
| Profile | Best use & specs |
|---|---|
| 5×6 M/F Interlock | Standard choice for longer spans and heavier loads. Male/female interlocking design creates a rigid, locked cover assembly. 3.65 lbs/LF (male plank). Repeat male/female pattern across span. |
| 2×7 Low-Profile | Best for short spans and tight vertical clearances — headworks, grinder rooms, and channel covers where equipment limits available height. 1.86 lbs/LF. |
Both profiles use 6005A-T5 alloy throughout — planks and flashing. Structural framing components (CS8 channels, L3×3 angles, mounting brackets) are 6061-T6. All fasteners are 316 stainless steel.
Key features
6005A-T5 alloy throughout
RPS specifies 6005A-T5 for all extruded planks and flashing — not the more commonly substituted 6061-T6. This is a deliberate engineering decision. 6005A-T5 offers superior extrudability for consistent, code-compliant profiles and performs better in the corrosive gas environments typical of wastewater treatment. When reviewing competitor submittals, confirm the alloy specification.
BABA compliant
All RPS aluminum cover products are domestically sourced and fabricated at our Elgin, IL facility, making them compliant with the Build America, Buy America Act. If your project uses SRF funding, USDA grants, or any federal infrastructure dollars, our aluminum covers qualify. Ask early — BABA requirements confirmed after award can force costly substitutions.
Bidirectional safety tread
All RPS flashing forms include a bidirectional non-skid surface as a standard feature — not an add-on. The walking surface meets slip-resistance requirements for operator safety without adhesive tape or coatings that can degrade over time.
Custom fit around in-tank equipment
No two tanks are identical. RPS planks are cut and fitted to accommodate odor control pipes, bar screens, slide gates, sensors, instrumentation, float switches, and any other in-tank equipment. RPS will fabricate aluminum stub-ups to match FRP pipes and custom flashings for sensor penetrations — so the cover seals properly around every penetration.
Odor & gas containment
The interlocking plank system with neoprene bulb gaskets at M/F joints and ribbed gaskets under flashing creates a substantially airtight cover assembly. The system is designed to work with an odor control ductwork connection, maintaining negative pressure inside the cover to prevent fugitive emissions at the perimeter. Meets air permit requirements and reduces odor complaints at the facility perimeter.
L/240 deflection standard: RPS flat covers are designed to L/240 — span length divided by 240. This is the structural deflection limit for the cover system under uniform and concentrated loads, ensuring long-term performance without sagging or joint failure.
System components
A complete RPS aluminum flat cover system includes the following components:
| Component | Function & spec |
|---|---|
| CS8 Channel (6061-T6) | Primary structural span. Planks sit on top. Secured to tank wall via mounting brackets. |
| L3×3 Angle (6061-T6) | Attaches to concrete wall. Provides the horizontal ledge that channels and planks rest on. |
| Mounting Bracket (6061-T6) | Secures channels to the wall. Bolted with 316 SS anchors into concrete. |
| 5×6 Female Plank (6005A-T5) | Outer plank with neoprene gasket in lower leg. Interlocks with male plank. 4.0 lbs/LF. |
| 5×6 Male Plank (6005A-T5) | Inner plank. Inserts into female. 3.65 lbs/LF. Repeat male/female pattern across span. |
| Extruded Flashing (6005A-T5) | Perimeter seal. 6″ wide, 3″ over wall, 3″ onto planks. Bidirectional non-skid surface. |
| Bulb Neoprene Gasket (EPDM) | At M/F plank joints and under flashing. Creates the airtight seal. 1/4×3/8″ at joints. |
| 316 SS Fasteners | Expansion anchors, hex head bolts, self-drilling screws throughout. No substitution. |
Specification reference
RPS aluminum flat covers are specified under CSI MasterFormat Section 13 33 12. RPS will provide a complete spec section ready to insert into project documents, and will work directly with the engineer of record during the design phase to answer RFIs and provide P.E.-stamped submittals.
Key spec requirements to confirm are included:
- 6005A-T5 for extruded planks and flashing
- 6061-T6 for structural components
- 316 SS fasteners throughout
- Bidirectional non-skid on all planks and flashing
- Field measurement prior to fabrication
Get a quote
Budget pricing is available from dimensions alone. A firm quote requires drawings and a completed Work Info Sheet. RPS field-measures before production — we never cut to CAD alone.
Women-owned · BABA compliant · ISO 9001 · 50+ years experience · Made in Elgin, IL · 1–2 week lead times
Contact Gina: gina-wwtp@rpsengineering.com | (847) 931-1950
