Ecovault Infiltration Chamber

Purpose
Underground infiltration chamber for dispersing urine and light greywater into soil in off-grid environments.

Primary Use
• Urine from urine-diverting toilets

Optional Use (when properly sized)
• Shower greywater
• Bathroom sink greywater 

Not intended for:
• Blackwater (feces or toilet paper)
• Kitchen grease discharge without pre-treatment
• Vehicular load applications

Application Type
Replacement for self-dug gravel infiltration pits.

Modular Design
Chambers can be connected in series to increase storage volume and infiltration area.

• 2 x 20 gallon Ecovault chamber
• 4 x grid for pipe entry points
• 6 x connector clips to attach chambers together
• 2 x non-woven geotextile fabric
• Simple assembly instruction

Important

Before installation, verify local regulations regarding urine and greywater discharge. Setback requirements from wells, property lines, foundations, and surface water vary by jurisdiction.

1. Site Selection

• Minimum 10 ft from building foundation
• Away from wells and surface water
• Above seasonal high groundwater table
• In well-draining soil
• Not in areas subject to vehicle traffic

Avoid heavy clay soils unless increasing chamber count.

2. System Sizing

Each assembled container is 20” x 20“ x 12” in size and can hold approximately 20 gallons of liquids. Infiltration system capacity can be increased by connecting multiple chambers together either by stacking or connecting them together in-line.

Urine Only (1–2 people, seasonal use): 1 chamber may be sufficient in well-draining soil, but it’s highly recommended to use 2 chambers either in chain or on top of each other.

Urine + Shower + Sink: Minimum 2 chambers recommended.

Full-time use typically requires 3 or more chambers.

When in doubt, increase chamber count rather than oversizing a single unit.

3. Excavation

Excavate a pit that's at least 3 inches wider than the chamber/chambers on each side and deep enough for:

• 4 inches gravel base
• Chamber height
• 2 inches of gravel cover
• 8 inches of soil cover

For a stacked installation of two chambers, the excavation should be at least 38" deep and measure 32" × 32".

For an in-line installation of two units, the excavation should be at least 26" deep and measure 32" × 52".

Install below frost depth in cold climates if used year-round.

4. Base Preparation

• Install 4–6 inches of ¾ inch clean washed drainage stone.
• Level and lightly compact.

5. Chamber Preparation

See the Chamber Preparation document for more detailed instructions.

• Assemble chamber / chambers
• Connect the chambers together if you use multiple chambers
• Cut an opening in the grid for the inlet pipe
• Wrap entire chamber in non-woven geotextile fabric. (Included)
• Overlap seams with a minimum of 12 inches.

Do not use plastic sheeting!

6. Plumbing Connection

• All lines must be gravity-fed.
• Maintain a minimum slope of 1/8 inch per foot.
• Use solid (non-perforated) PVC pipe.
• The maximum inlet pipe size is 5" Schedule 40 PVC.
• Position the end of the inlet pipe as close as possible to the center of the chamber.
• When connecting multiple sources to the same chamber, use a larger-diameter main pipe and connect the individual lines to this pipe along its length.

For shower connection: Install hair trap.

For sink connection: Install simple grease trap.

Do not allow solids, toilet paper, fats, or food waste to enter system.

7. Installation in Excavation

• Place wrapped chamber on gravel base.
• Connect inlet pipe securely. Inlet pipe end should be in the middle of the chamber/chambers.
• Surround sides with clean washed stone.
• Fold geotextile over top of chamber.
• Fill top with 2 inches of washed stone.

8. Backfill

• Backfill remaining depth with native soil.
• Compact gently in layers.

Final grade should slope away from structure.

Multiple Chamber Installation

Connect chambers in series to increase capacity.

• Install overflow from first chamber to next.
• Maintain equal elevation.

• Material: Durable PP plastic (Recycled)
• Shipping size: 20" x 20" x 15"
• Size of an assembled chamber: 20" x 20" x 12"
• Max pipe in: 5" schedule 40 PVC
• Minimum slope in: 1/8 inch per foot (1%)
• Shipping weight: 19 lbs
• Weight of one chamber: 8 lbs
• Storage capacity per chamber: approximately 19 gal
• Recommended cover depth: 8-12 inches of soil above
• Recommended base structure: 4–6 inches of ¾ inch clean washed drainage stone
• Geotextile Requirement: Non-woven geotextile wrap required to prevent soil intrusion (Included in delivery)
• Load rating: Not rated for vehicle traffic
• System Expansion: Units can be connected in series to increase system capacity

• Inspect and clean hair/grease traps every 6–12 months.
• Check for surface pooling after heavy use.
• Flush urine line if mineral buildup occurs.
• System longevity depends on preventing solids from entering the chamber.