5 Colo. Code Regs. § 1002-86.14

Current through Register Vol. 47, No. 20, October 25, 2024

Section 5 CCR 1002-86.14 - Graywater Use Requirements - Control Measures

A. Control measures are operational requirements representing best management practices that graywater treatment works must follow when operating a graywater treatment works.

B. Control measures that apply to all graywater uses:

All graywater treatment works must be operated in accordance with the following control measures:

1. Graywater must be collected in a manner that minimizes the presence or introduction of:

a. hazardous or toxic chemicals in the graywater to the greatest extent possible;

b. human excreta in the graywater to the greatest extent possible;

c. household wastes;

d. animal or vegetable matter, and

e. for Laundry to Landscape systems (Graywater Use Category A1), this includes control over the type of clothing in the washing machine (e.g. no reusable diapers; not using graywater when someone in the household is sick).

2. Use of graywater is limited to the confines of the facility that generates the graywater.

3. The graywater treatment works must be operated and maintained in accordance with the O&M manual, including all manufacturer recommended maintenance activities. The O&M manual must remain with the graywater treatment works throughout the system's life and be updated based on each modification and approval made to the system. The O&M manual must be transferred, upon change of ownership or occupancy, to the new owner or tenant.

a. For Category C2 graywater treatment works that have a capacity to receive greater than 2,000 gallons per day (gpd), operational and maintenance records must be maintained for a minimum of the past five (5) years.

4. The owner or operator of a graywater treatment works must minimize exposure of graywater to humans, domestic pets, and other animals.

5. Graywater use and graywater treatment works must not create a public nuisance.

6. Graywater must not be stored for more than 24 hours unless the graywater has been treated by a graywater treatment works that meets the design requirements of section 86.12. All graywater must be stored inside a tank(s) that meets the design requirements of section 86.12(A)(5).

7. Temporary or semi-temporary connections from the potable water system or public water system to the graywater treatment works are prohibited. Permanent connections from the potable water system or public water system to the graywater treatment works must meet the design requirements of 86.12(A)(6).

C. Control measures that apply to subsurface irrigation graywater use, including mulch basins (Graywater Use Categories: A1, B1, and B2)

Subsurface irrigation graywater treatment works must be operated in accordance with the following additional control measures:

1. Edible crop irrigation is prohibited for non-single family subsurface irrigation (Graywater Use Category: B2).

2. Edible crops irrigated with graywater treatment works must be washed with potable water prior to consumption.

3. Edible crops irrigated with graywater treatment works must be for personal consumption only and not for sale.

4. Single family units that allow for short term rentals (e.g. Airbnb, VRBO, etc.) are prohibited from using graywater for edible crop irrigation and Laundry to Landscape graywater treatment works.

5. Irrigation of sprouts, leafy greens and root crops is prohibited.

6. Irrigation is prohibited when the ground is frozen, plants are dormant, during rainfall events, or the ground is saturated.

7. Irrigation scheduling must be adjusted so that application rates are closely matched with soil and weather conditions.

8. Graywater must be applied in a manner that does not result in ponding, runoff, or unauthorized discharge to state waters. For dispersed subsurface irrigation systems, the graywater must be applied at an agronomic rate. For mulch basins systems, the graywater must not be applied in excess of the soil adsorption rate.

9. For mulch basin systems, mulch must be replenished and undergo periodic maintenance as needed to reshape or remove material to maintain surge capacity and to prevent ponding and runoff.

D. Control measures that apply to indoor toilet and urinal flushing graywater use (Graywater Use Categories: C1 and C2)

Indoor toilet and urinal flushing graywater treatment works (Categories C1 and C2) must be operated in accordance with the following additional control measures.

1. Graywater for toilet and urinal flushing use must be disinfected.

a. Graywater treatment works that utilize chlorine for disinfection must have a minimum of 0.2 mg/L and a maximum of 4.0 mg/L of free chlorine residual throughout the indoor graywater plumbing system, including fixtures.

b. Single family graywater treatment works that utilize non-chemical methods, such as UV, for disinfection must have a chlorine puck present in each toilet or urinal tank.

2. Graywater for toilet and urinal flushing must be dyed with either blue or green food grade vegetable dye and be visibly distinct from potable water.

E. Control measures that apply to rural fire protection graywater use (Graywater Use Categories: D1 and D2)

Rural fire protection graywater treatment works (Categories D1 and D2) must be operated in accordance with the following additional control measures.

1. Graywater for rural fire protection use must be stored in a watertight storage cistern consistent with 86.10(F)(3) for single family graywater treatment works and 86.10(G)(3) for non-single family graywater treatment works.

2. Graywater for rural fire protection use must be disinfected prior to graywater entering the storage cistern.

b. UV disinfection prior to being pumped to the storage cistern.

3. The local fire district/authority must be notified and agree to graywater use for fire protection prior to its adoption and use in a local city, city and county or county.

5 CCR 1002-86.14

38 CR 11, June 10, 2015, effective 6/30/2015

38 CR 23, December 10, 2015, effective 12/30/2015

46 CR 24, December 25, 2023, effective 1/14/2024