Overview
Watertight, Easy-to-Install, Custom Tank Top Containment
Our extensive offering of world-class fiberglass tank sumps provide you with a solution for virtually any type of tank top containment. Manufactured using only the highest quality fiberglass reinforced polymer (FRP), these sumps come complete with a watertight sump shield and gasketed cover with strap-down toggles to keep your containment free from costly liquid intrusion
Highlights:
- Each fiberglass tank sump includes a sump base, a riser, a reducer collar (factory-fiberglassed to the riser), and watertight sump shield with strap-down cover.
- Available in 42” and 48” base diameters.
- Reducer collars and reducer sump shields allow any tank sump to fit under a 36” manway while providing a 30” diameter clear opening for easy access to equipment.
- Constructed from rugged ¼” thick, three-layer, hand layup fiberglass reinforced polymer (FRP).
- White gel coat interior provides a vapor and watertight barrier and superior visibility.
- Single wall models are available with or without bottom for various mounting options.
- Double wall models are only available with a bottom for mounting to tank collar.
- Double wall models are shipped under vacuum with a vacuum gauge installed for verification at site of sealed interstitial.
- Octagonal base sumps feature a two-piece design that eliminates confined spaces and gives installers full access to the containment during installation.
- Once equipment installation is complete, the two-piece design is connected using a fiberglass seam kit (ordered separately) to ensure a seamless, watertight joint.
- Eight flat panels are molded into the bottom section of octagonal base sumps to provide 90° pipe entries.
- The watertight sump shield keeps liquid out of the containment space during normal operation while allowing easy access to the containment space for maintenance or inspection.
- Six strap down toggles and internal D-gasket ensure the cover stays in place.
Specs:
- Base
- Riser
- Reducer collar
- Sump shield
- Cover (gasketed)
- Strap-down toggles
- Flat panels

Order Info:
42” Single Wall – Medium Bury – Octagonal Two-Piece Base with Bottom
 | - Min. manway diameter: 36”
- Clear opening diameter: 30”
- Medium bury depth: 45”
- Sump base depth: 15”
- Sump base diameter: 42¼”
- Inside diameter: 39¼”
- Flat panel width: 12”
- Flat panel height: 9”
- Field height adjustment: 12”
| Model | Wall Type | Depth | Riser Base Dia. (in) | Min. Manway Size (in) | Seam Kits Recommended | | TM4236-0/0-OB-S | Single | Medium | 42 | 36 | 1 | The sump base comes with a solid fiberglass bottom that is ideal for installations with an existing tank fitting adapter or tank manway adapter in place. Download the Datasheet for Dimensions drawing. |
42” Single Wall – Deep Bury – Octagonal Two-Piece Base with Bottom
 | - Min. manway diameter: 36”
- Clear opening diameter: 30”
- Deep bury depth: 65”
- Sump base depth: 15”
- Sump base diameter: 42¼”
- Inside diameter: 39¼”
- Flat panel width: 12”
- Flat panel height: 9”
- Field height adjustment: 12”
| Model | Wall Type | Depth | Riser Base Dia. (in) | Min. Manway Size (in) | Seam Kits Recommended | | TD4236-0/0-OB-S | Single | Deep | 42 | 36 | 1 | The sump base comes with a solid fiberglass bottom that is ideal for installations with an existing tank fitting adapter or tank manway adapter in place. Download the Datasheet for Dimensions drawing. |
42” Single Wall – Medium Bury – Octagonal Two-Piece Collar Mount Base
 | - Min. manway diameter: 36”
- Clear opening diameter: 30”
- Medium bury depth: 45”
- Sump base depth: 15”
- Sump base diameter: 42¼”
- Inside diameter: 39¼”
- Flat panel width: 12”
- Flat panel height: 9”
- Field height adjustment: 12”
| Model | Wall Type | Depth | Riser Base Dia. (in) | Min. Manway Size (in) | Seam Kits Recommended | | TM4236-0/0-OC-S | Single | Medium | 42 | 36 | 2 | The sump base comes with an open bottom that is ideal for installations with a tank collar in place. Download the Datasheet for Dimensions drawing. |
42” Single Wall – Deep Bury – Octagonal Two-Piece Collar Mount Base
 | - Min. manway diameter: 36”
- Clear opening diameter: 30”
- Medium bury depth: 65”
- Sump base depth: 15”
- Sump base diameter: 42¼”
- Inside diameter: 39¼”
- Flat panel width: 12”
- Flat panel height: 9”
- Field height adjustment: 12”
| Model | Wall Type | Depth | Riser Base Dia. (in) | Min. Manway Size (in) | Seam Kits Recommended | | TD4236-0/0-OC-S | Single | Deep | 42 | 36 | 2 | The sump base comes with an open bottom that is ideal for installations with a tank collar in place. Download the Datasheet for Dimensions drawing. |
42” Single Wall – Medium Bury – Round Single-Piece Collar Mount Base
 | - Min. manway diameter: 36”
- Clear opening diameter: 30”
- Medium bury depth: 54”
- Sump base diameter: 42¼”
| Model | Wall Type | Depth | Riser Base Dia. (in) | Min. Manway Size (in) | Seam Kits Recommended | | TMA4236-0/0-RC-S | Single | Medium | 42 | 36 | 2 | The sump base comes with an open bottom that is ideal for installations with a tank collar in place. Download the Datasheet for Dimensions drawing. |
42” Single Wall – Deep Bury – Round Single-Piece Collar Mount Base
 | - Min. manway diameter: 36”
- Clear opening diameter: 30”
- Medium bury depth: 70”
- Sump base diameter: 42¼”
| Model | Wall Type | Depth | Riser Base Dia. (in) | Min. Manway Size (in) | Seam Kits Recommended | | TDA4236-0/0-RC-S | Single | Deep | 42 | 36 | 2 | The sump base comes with an open bottom that is ideal for installations with a tank collar in place. Download the Datasheet for Dimensions drawing. |
48” Single Wall – Medium Bury – Octagonal Two-Piece Base with Bottom
 | - Min. manway diameter: 36”
- Clear opening diameter: 30”
- Medium bury depth: 45”
- Sump base depth: 28½”
- Sump base diameter: 48¼”
- Inside diameter: 42”
- Flat panel width: 15”
- Flat panel height: 21”
| Model | Wall Type | Depth | Riser Base Dia. (in) | Min. Manway Size (in) | Seam Kits Recommended | | TMA4836-0/0-OB-S | Single | Medium | 48 | 36 | 2 | The sump base comes with a solid fiberglass bottom that is ideal for installations with an existing tank fitting adapter or tank manway adapter in place. Download the Datasheet for Dimensions drawing. |
48” Single Wall – Deep Bury – Octagonal Two-Piece Base with Bottom
 | - Min. manway diameter: 36”
- Clear opening diameter: 30”
- Medium bury depth: 65”
- Sump base depth: 28½”
- Sump base diameter: 48¼”
- Inside diameter: 42”
- Flat panel width: 15”
- Flat panel height: 21”
- Field height adjustment: 12”
| Model | Wall Type | Depth | Riser Base Dia. (in) | Min. Manway Size (in) | Seam Kits Recommended | | TDA4836-0/0-OB-S | Single | Deep | 48 | 36 | 2 | The sump base comes with a solid fiberglass bottom that is ideal for installations with an existing tank fitting adapter or tank manway adapter in place. Download the Datasheet for Dimensions drawing. |
48” Single Wall – Medium Bury – Octagonal Two-Piece Collar Mount Base
 | - Min. manway diameter: 36”
- Clear opening diameter: 30”
- Medium bury depth: 45”
- Sump base depth: 28½”
- Sump base diameter: 48¼”
- Inside diameter: 42”
- Flat panel width: 15”
- Flat panel height: 21”
| Model | Wall Type | Depth | Riser Base Dia. (in) | Min. Manway Size (in) | Seam Kits Recommended | | TMA4836-0/0-OC-S | Single | Medium | 48 | 36 | 3 | The sump base comes with an open bottom that is ideal for installations with a tank collar in place. Download the Datasheet for Dimensions drawing. |
48” Single Wall – Deep Bury – Octagonal Two-Piece Collar Mount Base
 | - Min. manway diameter: 36”
- Clear opening diameter: 30”
- Medium bury depth: 65”
- Sump base depth: 28½”
- Sump base diameter: 48¼”
- Inside diameter: 42”
- Flat panel width: 15”
- Flat panel height: 21”
- Field height adjustment: 12”
| Model | Wall Type | Depth | Riser Base Dia. (in) | Min. Manway Size (in) | Seam Kits Recommended | | TDA4836-0/0-OC-S | Single | Deep | 48 | 36 | 3 | The sump base comes with an open bottom that is ideal for installations with a tank collar in place. Download the Datasheet for Dimensions drawing. |
48” Single Wall – Medium Bury – Round Single-Piece Collar Mount Base
 | - Min. manway diameter: 36”
- Clear opening diameter: 30”
- Medium bury depth: 41”
- Sump base diameter: 48”
| Model | Wall Type | Depth | Riser Base Dia. (in) | Min. Manway Size (in) | Seam Kits Recommended | | TMA4836-0/0-RC-S | Single | Medium | 48 | 36 | 2 | The sump base comes with an open bottom that is ideal for installations with a tank collar in place. Download the Datasheet for Dimensions drawing. |
48” Single Wall – Deep Bury – Round Single-Piece Collar Mount Base
 | - Min. manway diameter: 36”
- Clear opening diameter: 30”
- Medium bury depth: 65”
- Sump base diameter: 48”
| Model | Wall Type | Depth | Riser Base Dia. (in) | Min. Manway Size (in) | Seam Kits Recommended | | TDA4836-0/0-RC-S | Single | Deep | 48 | 36 | 2 | The sump base comes with an open bottom that is ideal for installations with a tank collar in place. Download the Datasheet for Dimensions drawing. |
42” Double Wall – Medium Bury – Octagonal Two-Piece Base with Bottom
 | - Min. manway diameter: 36”
- Clear opening diameter: 30”
- Medium bury depth: 45”
- Sump base depth: 15”
- Sump base diameter: 42¼”
- Inside diameter: 39¼”
- Flat panel width: 12”
- Flat panel height: 9”
- Field height adjustment: 12”
| Model | Wall Type | Depth | Riser Base Dia. (in) | Min. Manway Size (in) | Seam Kits Recommended | Interstitial Monitoring Type | | TM4236-0/0-OC-H | Double | Medium | 42 | 36 | 2 | Hydrostatic | | TM4236-0/0-OC-V | Double | Medium | 42 | 36 | 4 | Vacuum | The sump base comes with a solid fiberglass bottom that is ideal for installations with an existing tank fitting adapter or tank manway adapter in place. Choose between hydrostatic (brine) or vacuum interstitial monitoring options. Download the Datasheet for Dimensions drawing. |
48” Double Wall – Medium Bury – Octagonal Two-Piece Base with Bottom
 | - Min. manway diameter: 36”
- Clear opening diameter: 30”
- Medium bury depth: 45”
- Sump base depth: 28½”
- Sump base diameter: 48¼”
- Inside diameter: 42”
- Flat panel width: 15”
- Flat panel height: 21”
| Model | Wall Type | Depth | Riser Base Dia. (in) | Min. Manway Size (in) | Seam Kits Recommended | Interstitial Monitoring Type | | TM4836-0/0-OC-H | Double | Medium | 48 | 36 | 3 | Hydrostatic | | TM4836-0/0-OC-V | Double | Medium | 48 | 36 | 4 | Vacuum | The sump base comes with a solid fiberglass bottom that is ideal for installations with an existing tank fitting adapter or tank manway adapter in place. Choose between hydrostatic (brine) or vacuum interstitial monitoring options. Download the Datasheet for Dimensions drawing. |
48” Double Wall – Deep Bury – Octagonal Two-Piece Base with Bottom
 | - Min. manway diameter: 36”
- Clear opening diameter: 30”
- Medium bury depth: 65”
- Sump base depth: 28½”
- Sump base diameter: 48¼”
- Inside diameter: 42”
- Flat panel width: 15”
- Flat panel height: 21”
- Field height adjustment: 12”
| Model | Wall Type | Depth | Riser Base Dia. (in) | Min. Manway Size (in) | Seam Kits Recommended | Interstitial Monitoring Type | | TD4836-0/0-OC-H | Double | Deep | 48 | 36 | 3 | Hydrostatic | | TD4836-0/0-OC-V | Double | Deep | 48 | 36 | 4 | Vacuum | The sump base comes with a solid fiberglass bottom that is ideal for installations with an existing tank fitting adapter or tank manway adapter in place. Choose between hydrostatic (brine) or vacuum interstitial monitoring options. Download the Datasheet for Dimensions drawing. |
Watertight Sump Shield Packages
 | | Model | Riser Base Dia. (in) | Access Opening (in) | Min. Manway Size (in) | Seam Kits Recommended | | TSS-4236 | 42 | 30 | 36 | 1 | | TSS-4836 | 48 | 30 | 36 | 1 | | TSS-XS36 | Xerxes® | 30 | 36 | 1 | Used for repair and replacement work or if the tank sump or riser is provided by the tank manufacturer. Provides a watertight entry point for standard 42” and 48” tank sumps. Includes sump shield with strap-down cover and riser reducer. |
Fiberglass Seam Kits
 | | Model | Description | | FIBERGLASS-KIT | Fiberglass seam kit for one seam – includes: matte, resin, putty, catalyst, ½” x 3” roller, 2” brush, quart cups (qty 3), stir sticks (qty 2), squeegee, glove – size large (qty 2 pairs) | |
Fiberglass Tank Sump Replacement Parts
 | | Model | Description | | TSS-36 | 36” watertight sump shield lid, with toggles | | 602226906 | 42” watertight sump shield lid, with toggles | | 602212001 | Sump shield lid gasket for 36” sump shield lid | | 602212002 | Sump shield lid gasket for 42” sump shield lid | | 602221902 | Sump adapter for 42” sump base to 36” lid adapter | | 602221904 | Sump adapter for 42” sump base to 42” lid adapter | | 602226901 | Sump adapter for 48” sump base to 36” lid adapter | | 602330901 | Bracket assembly, attaches on the riser adapter (bottom) | | 602331001 | Rubber pull latch | |