Download the Limited Use Wastewater Information as a PDF

Vault - A minimum 1250 gallon watertight, sealed tank designed to store wastewater. Vaults must be equipped with a signaling device to indicate when they are reaching capacity and must be pumped when full.

Vaulted Privy - A minimum 400 gallon concrete, plastic, or fiberglass tank with a "privy" or outhouse structure built over the tank.

Composting Toilet - A self-contained, waterless toilet unit that reduces waste through aerobic decomposition.

Portable Chemical Toilet - A temporary self contained privy and tank that are typically used during construction or to increase capacity for large temporary special events.

Graywater - Wastewater generated from lavatory sinks, showers, and laundry. Excludes wastewater from kitchen sinks and toilets.

What is a limited use wastewater system?
Limited use wastewater systems include vaults, vaulted privies, composting or incinerating toilets, and portable chemical toilets. These systems are intended to provide an option for handling wastewater on properties where the quantity of wastewater produced will be minimal, or properties which cannot accommodate an on-site wastewater treatment system (OWTS) with a soil treatment area. 
Dwellings built as cabins without plumbing and hauling or hand carrying their primary source of water, RVs used on properties seasonally, and semi-permanent campsites are the primary users of limited use wastewater systems.  

When can a limited use wastewater system be used?
Use of these systems is limited to seasonal or short-term use dwellings, properties that cannot accommodate an OWTS with a soil treatment area, areas where the installation of a full system is prohibited, or when the source of water is hauled or hand carried.

The cost of maintaining these systems can be very high due to the need for frequent pumping of vaults or holding tanks. Limited use wastewater systems are not permitted on properties that are used or could potentially be used for full-time occupancy, when water is provided by a well or public water supply, except in cases where a full OWTS is not feasible or prohibited.

Can a vault be installed for a cabin or seasonal dwelling? 
A vault, vaulted privy, or composting toilet can be used provided the dwelling is built as a cabin per the Larimer County Land Use Code definition and Building Department requirements, and is built without plumbing or the source of water is hauled or hand carried to the site. Due to the high cost of maintaining these systems long-term, a full on-site wastewater system is recommended. 

For structures built as a single family dwellings, cabins with water supplied by a well or public water system, or cabins converted to single family dwellings, a full OWTS must be installed unless the property cannot accommodate the full system with soil treatment area. Seasonal or part-time use alone can not be considered as a justification for a limited use wastewater system. 

Can graywater be disposed of on the ground?
No, graywater from showers, laundry, or sinks must be collected and disposed of as wastewater. Running lines from RVs or dwellings out to the ground is prohibited by Larimer County OWTS Regulations.  

Graywater contains bacteria, viruses, soaps and detergents, as well as other contaminants that can impact groundwater and surface water, potentially causing contamination to drinking water wells, lakes, and streams.  

When is a permit required? 
A permit is required prior to the installation of a limited use wastewater system. On new construction, arrangements must be made for how wastewater will be handled prior to a building permit being issued. On land that is currently vacant, a permit must be applied for prior to installing a vault or vaulted privy. 

Limited use wastewater systems during construction
Portable chemical toilets are only permitted on properties during construction of a dwelling, or in emergency circumstances.  Alternatively, a vault, septic tank used as a vault, or full septic system may be installed and connected to temporary living quarters until construction is complete.  

Septic Systems

Questions? Contact OWTS

Call (970) 498-6775