Onsite Wastewater System (OWS)
VAULTS

Why a Vault Policy is Important

• Soil absorption and treatment is a more effective method for wastewater treatment than a vault.

• Vaults require a higher level of maintenance and monitoring than do conventional soil absorption systems; therefore, they are more reliant on appropriate occupant behaviors that may not be passed along to subsequent owners.

• Since vaults can be installed within close proximity (50 feet) to a well they can significantly compromise local water quality.

• Because of the high cost of pumping, cleaning, and septage hauling, vault installations are often associated with the unapproved disposal of greywater onto landscaping.

BCPH Vault Policy Summary

The owner of any property with a vault that is triggered for review (e.g. property transfer, building permit referral, or land use review) must:

1. Prove that a regular* system cannot be installed by having the site evaluated for suitability for soil absorption, given that technologies may have advanced since the original installation; AND
    

2. Have the vault inspected by a National Association of Wastewater Transporters (NAWT)-certified inspector to determine tank integrity and alarm function, and to ensure that greywater plumbing is connected to the tank; AND

3. Reduce occupancy to 60 days or less; OR
    

4. Request a variance from the regulation by the Boulder County Board of Health
   Note: Prerequisites of Board of Health variance approval are a site evaluation for soil absorption and a NAWT inspection.

If a variance is approved, BCPH will expect to implement the following vault management policies:

1. Evaluate the operation and maintenance on a quarterly basis.

2. Include language on the permit or on a declaration that states that the vaulted property will be upgraded when new technology becomes available, or when regulations allow.

3. Gather water metering and vault pumping receipts from the property owner to ensure that all household water is going into the vault (i.e. water in equals water out).

* A regular system is defined as any engineered or standard gravity flow soil absorption system that utilizes a leach field and treatment tank. It must have soil absorption for all greywater and black water.

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Please Note: This information is intended to provide a better understanding of the functions of onsite wastewater treatment and the need for proper design, installation, and maintenance. Always consult a licensed professional or public health official with questions regarding engineering, installation, and servicing of onsite wastewater systems.