Exhibit A
ORDINANCE NO. 594
ORDINANCE NO. 724 (amended)
City of Larkspur
SEWER USER STRENGTH FACTORS
|
Parameter Allocations1 |
Assumed Loadings For Average Residential Unit2 |
|---|---|
|
Flow 55.2% |
Flow 250 gallons/day |
|
BOD 22.4% |
BOD 200 mg/1 |
|
SS 22.4% |
SS 200 mg/1 |
Strength Factor = Daily Flow [.552 + BOD concentration3 (.224) + SS concentration3 (.224)]
Unit Assignment2 250 200 200
|
Assumed Loadings |
||||
|---|---|---|---|---|
|
User Group |
Flow gallons/day |
BOD mg/1 |
SS mg/1 |
Strength Factor for 250 gallons/day |
|
Average residential unit |
250 |
200 |
200 |
1.00 |
|
Restaurants |
– 4 |
1,000 |
600 |
2.34 |
|
Mortuaries |
– 4 |
800 |
800 |
2.34 |
|
Markets with disposals |
– 4 |
800 |
800 |
2.34 |
|
Bakeries |
– 4 |
800 |
800 |
2.34 |
|
Other commercial & service |
– 4 |
200 |
200 |
1.00 |
1These parameters allocate both capital and operating costs of the facilities among flow, biochemical oxygen demand (BOD) and suspended solids (SS).
2Formula is designed to provide a multiplier for high strength flows.
3Minimum concentration for any user assumed to be 200 mg/1 BOD and 200 mg/1 suspended solids.
4Based on actual water consumption records.