Policies, Rules & Rates : Calculation of Living Unit Equivalents
Calculation of Living Unit Equivalents
CALCULATION OF LIVING UNIT EQUIVALENTS:
For purposes of this Rate and Fee Schedule, the calculation of LUEs shall be determined as follows:
- Definition: A living unit equivalent (LUE) is defined as the typical flow that would be produced by a single family residence (SFR) located in a typical subdivision. For water, this includes consumptive uses such as lawn watering and evaporative coolers. The wastewater system does not receive all of these flows, so the expected flows per LUE differ for water and wastewater.
- ONE LUE produces:
2.2 gallons per minute (GPM) in a Peak Hour of water flow
1.0 GPM in a Peak Day of water flow
0.33 GPM on an average basis year round.
270 GPD average dry weather wastewater flow.
- LUEs shall be determined in accordance with the following AWWA meter equivalent recommendations as follows:
| Meter Type |
Meter Size |
Continuous Duty
Maximum Rate
(GPM)
|
Ratio to 5/8" Meter
AWWA Standards
C700, C701, C702, C703
|
| Simple |
5/8" |
10 |
1.0 |
| Simple |
3/4" |
15 |
1.5 |
| Simple |
1" |
25 |
2.5 |
| Simple |
1-1/2" |
50 |
5.0 |
| Simple |
2" |
80 |
8.0 |
| Compound |
2" |
100 |
10.0 |
| Compound |
3" |
240 |
24.0 |
| Compound |
4" |
420 |
42.0 |
| Compound |
6" |
920 |
92.0 |
| Compound |
8" |
1600 |
160.0 |
| Compound |
10" |
2500 |
250.0 |
| Compound |
12" |
3300 |
330.0 |
CALCULATION OF EQUIVALENT RESIDENTIAL UNIT (ERU):
For purposes of this rate and fee schedule, calculation of ERU values shall be determined as follows:
1. Definition: An An Equivalent Residential Unit represents the median single family residential impervious are for the District, which has been determined to be 4,000 square feet.
a. Residential Class: Single Family Residential properties shall be assessed (1) ERU per month.
b. Non-Residential Class: For non-residential properties, the number of ERUs is based on the actual impervious cover for the parcel divided by the ERU value of 4,000 square feet.
For illustration, if a non-residential property has an impervious area of 10,000 square feet, its ERU value would be calculated as follows:
10,000 (property-specific impervious area) / 4,000 (ERU value) = 2.5 ERUs
2. Definition: Impervious Area (or impervious surface) means a surface that has been compacted or covered with a layer of material so that it is resistant to infiltration by water and does not have a natural state of vegetative cover. Impervious areas include, but are not limited to, compacted soils with a surface treatment, gravel, crushed stone surfaces or soil compacted by vehicle traffic, asphalt or concrete pavement, parking lots, driveways, sidewalks and private roadways, and buildings, and other manmade structures, surfaces, or any uses that change the natural surface of the land and have the effect of increasing, concentrating, or otherwise altering stormwater runoff from that experienced under natural vegetative conditions.