5 Colo. Code Regs. § 1002-86.11

Current through Register Vol. 47, No. 20, October 25, 2024
Section 5 CCR 1002-86.11 - Graywater Treatment Works - Flow Projections
A. Flow projections for all graywater treatment works
1. Graywater treatment works must be sized appropriately using the following flow projection methods:
a. Single family users: Flow to graywater treatment works must be calculated on the occupancy and the fixtures connected to the graywater treatment works. The calculated graywater flow is the number of occupants multiplied by the estimated graywater flow in terms of gpd/occupant from the fixtures connected to the graywater treatment works. For Laundry to Landscape, flow is calculated based on the number and type of laundry machines connected to the system.
i. The occupancy must be calculated based on a minimum of two (2) occupants for the first bedroom and one (1) occupant for each additional bedroom. In all cases, the maximum occupancy must be based on the maximum potential use of the property and not the current population or use.
ii. The estimated graywater flow from each fixture is based on the design flow of the fixture, or if the fixture's design flow is unknown then the estimated graywater flow per occupant is based on the following gallons per day per occupant (gpd/occupant).
(a) Non-WaterSense fixtures: 25 gpd/occupant for each bathroom and laundry room sink, bathtub and shower.
(b) WaterSense fixtures: 20 gpd/occupant for each bathroom and laundry room sink, bathtub and shower.
(c) Laundry machines:
1. For ENERGY STAR rated laundry machines with a provided Integrated Water Factor, use the following flow projection estimate:

Gpd/occupant = IWF x volume (cu. ft.) x average loads per week / maximum number of days occupied per week

Where:

IWF = Integrated Water Factor (Note: Determination of whether the appliance is designated, has an IWF and to determine the IWF, visit the Department of Energy's ENERGY STAR Certified Residential Clothes Washers website: https://www.energystar.gov/productfinder/product/certified-clothes-washers/)

Volume = Capacity of laundry machine

Maximum number of days occupied per week = seven (7)

2. For ENERGY STAR rated laundry machines without a provided Integrated Water Factor use 8 gpd/occupant for each laundry machine.
3. For laundry machines that are not ENERGY STAR rated use 10 gpd/occupant for each laundry machine.
b. Non-single family users: Graywater treatment works must be sized in accordance with the maximum occupancy and use of the facility. The occupancy must be calculated based on the total, maximum daily population served by the graywater treatment works including but not limited to employees, visitors, and customers. In all cases, the maximum daily population must be based on the maximum potential use of the property and not the current population or use.
i. The estimated graywater flow from each fixture is based on the design flow of the fixture or, if the fixture's design flow is unknown, then the estimated graywater flow per occupant is based on the gallons per day per occupant provided under 86.11(A)(1)(a)(ii) of this regulation.

5 CCR 1002-86.11

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