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A £10,000 per year water leak! Water leak detection site survey report.
We attended the Stockport site on 29th May 2013 to carry out leak detection after receiving a high consumption bill.
Upon arrival at site we checked and inspected the area and identified three separate water meters, all of which serve the complex.
Meter Serial Number: C09AU04
We began our investigations by carrying out a flow check on the above meter located on the grass verge adjacent to the forecourt. The meter was reading 4308m³ with a flow rate of 0.04m³ per hour. This equates to a usage of 1.008m³ per day, 367.9m³ per annum and an annual cost of £1,000.74.
We conducted a flow check by opening the cold water tap in the kitchen area of the showroom which brought about a change in flow at the meter.
A primary step test was then conducted which consisted of closing the internal stop tap which brought the meter register to a halt. This exercise confirmed that there was no underground leakage present.
An internal audit of water fittings highlighted a constant flow of water located on the ground floor urinal installation. Initially, there was no evidence of a cisternmiser urinal control fitted on this urinal. We inspected the first floor urinal to see if there was any evidence of a control device fitted. We found a cisternmiser urinal control fitted on the first floor urinal which would lead us to believe that one was fitted on the ground floor urinal but had unfortunately failed.
Meter Serial Number: 2213445
We carried out a flow check on the second meter on site. This meter is located on the grass verge in front of the showroom and, upon inspection, was reading 3495m³.
We opened the cold water tap in the kitchen area of the showroom which brought about a change in the water flow at the meter.
However, upon closing the tap, the meter once again became stationary which would indicate no leakage is present on this supply.
Meter Serial Number: 05A214552
The meter of the above reference was of particular interest to our engineers. The 25mm water meter is fitted to a 63mm medium-density polyethylene pipe supply.
A member of staff on site asked if we were investigating a water leak, when we advised that we were the member of staff directed us to a small brick building adjacent to the car wash facility.
He explained that a water tank was situated within the building and that the overflow was seen to be running at various times for lengthy periods.
When we investigated this further, it came to our attention that the building contained a cold water tank and booster pumps. It became apparent that the break tank arrangement had been fitted to meet water regulations with regards to backflow prevention and contamination of water supplies caused by oil, fuel and detergents.
At the time of inspection, water was flowing into the tank via a ball valve. When we examined the ball valve, we became aware that this had a tendency to stick.
We carried out a flow check at the meter with the ball valve fully closed and this produced a stationary meter register which indicated that no underground leakage is present. Opening the ball valve caused the meter register to operate which indicates that the meter is operating correctly.
The overall leakage rate for this meter was 0.007m³/min which equates to a usage of 10.08m³ per day and an annual cost of £10,007.42.
Recommendations
- Replace urinal control on ground floor as current urinal control is not working
- Replace faulty ball valve as the current one is not functioning correctly
- Once the above repairs have been completed we will liaise with the water supplier on your behalf to claim a leakage refund for the water lost due to the faulty break tank as the water has returned to ground and not to the sewer.
Picture 1 – The building containing the break tank where the faulty ball valve was identified Picture 2 – The overflow pipe from the break tank where water had been seen running for lengthy periods of time
