Before we get into implementing any plans to cut down the water waste, the first step is to look at the usage for the last 12 months.
- WATER AUDIT
The average water used by apartment buildings per unit is as follows:
- First Resident 75 gallons/day
- Second Resident 35 gallons/day
- Third Resident 25 gallons/day
So for a 20-unit apartment complex:
- Five – Studios 1 Resident 75 gallons/day x 5 = 375 gallons/day
- One – 1 Bedroom 2 Residents 110 gallons/day x 10 = 1,100 gallons/day
- Five – 2 Bedroom 3 Residents 135 gallons/day x 5 = 675 gallons/day
TOTAL 2,150 gallons/day
For one month = 2,150 x 30 64,500 gallons/month
Most of the cities in Minnesota charge by 1,000 gallons or 100 cubic feet (7.48 gallons/cubic foot.) The average cost in metro Minnesota is $6.00/1,000 gallons for water and sewer.
The cost for 20-unit apartment building should be: 64.5 x 6 = $387.00 for 20 units or $19.35/unit
This average usage can be reduced by 25 – 30%.
Now you can compare this with your actual usage and see where you stand.
- WATER PRESSURE AT THE BUILDING
The pressure required at plumbing fixtures from sink, dishwasher, toilet, shower varies from 8 psi – 20 psi.
Pressure at the water meter to supply the farthest and highest fixture during peak demand usually 50 psi pressure is enough to handle a 3-story apartment building. You lose 1 lb of pressure for every 2.31-foot rise; so for 30’ rise you lose 13 psi of pressure.
You should check the water pressure at the meter. Over 60 psi pressure, you should consider lowering the pressure with pressure reducing valve.
The water flow is twice at 150 psi compared to 50 psi.
The water flow is 33% higher at 100 psi compared to 50 psi.
3. RECOMMENDED FLOW FOR PLUMBING FIXTURES
Toilet —————-1.6 gallons per flushing cycle
Showerhead ——–2.0 – 2.5 gpm
Lav Faucet———-1.5 gpm
Kitchen Sink——–1.5 gpm
- FIXTURE MAINTENANCE
• Check for leaky faucets.
• Check for leaky toilets.
Problem with a toilet: Put food coloring in the tank and don’t flush the toilet. If the color runs through the bowl, then your flapper is not sitting over the opening and water is seeping from the tank – Replace the flapper.
• Check for leaky diverters. For tub/shower combination (replace O ring if leaking.)
5. COST OF WATER/SEWER IN METRO MINNESOTA
City of Hopkins—————$5.30 / 1,000 gallons
City of Eden Prairie———-$3.98 / 1,000 gallons
City of New Hope————$8.60 / 1,000 gallons
City of Roseville————–$5.35 / 1,000 gallons
City of St. Paul —————$7.30 / 1,000 gallons
City of Minneapolis———-$6.64 / 1,000 gallons
WISH YOU HAPPY WATERWISE MANAGEMENT!