Weld County, Colorado On-Site Wastewater Treatment System Regulations Study Guide.

Mound: Above original grade soil treatment.

Nitrogen Reduction: 50% reduction of influent nitrogen strength.

Percolation Test: Determines water absorption capacity of the soil.

Note: Expressed in minutes per inch of water.

Permeability: Property of a material which permits movement of water through it.

Riser: Watertight vertical cylinder and lid allowing access to an OWTS component.

Sand Filter: A type of OWTS that uses a layer of sand as a filter and uses pressure distribution.

Trench: Below-grade soil treatment area 3’ wide or less containing distribution media and one lateral.

Nice study guide, Nick!

Abbreviations:

GPD: Gallons Per Day
ISDS: Individual Sewage Disposal System
LTAR: Long Term Acceptance Rate
MPI: Minutes Per Inch
NDDS: Non-pressurized Drip Dispersal Systm
OWTS: On-site Wastewater Treatment System
STA: Soil Treatment Area
TL: Treatment Level
TSS: Total Suspended Solids

If both a building permit and OWTS permit are issued for the same property, the OWTS permit shall expire at the same time as the building permit.

Otherwise, an OWTS expires in a year if construction is not commenced.

A permit is required for the expanded use (higher flow rate) of an OWTS.

No OWTS permit shall be issued if there is a public sewer available.

Treatment systems other than those discharging through a soil treatment area or sand filter system must be designed by a P.E.

If you have an OWTS on your property, you have to permit access to the property to make inspections, conduct tests, take samples, and monitor compliance.

The Division has to make it’s final inspection within 72 hours of being notified that the OWTS construction is completed. Saturdays, Sundays, and holidays are not counted.

If the OWTS was required to be designed and installed under the supervision of an engineer, the engineer must certify in writing that it was installed properly.

Employees of a licensed systems contractor need not also be licensed.

System Contractor’s licenses expire every year.

A system contractor license is not needed for owner-installers who have obtained permits (one per year permitted).

No variances will be issued where the property can have a conforming OWTS.