Lead Contamination in Drinking Water
Lead contamination at the new Perth Children’s Hospital continues to be a major obstacle delaying the opening of the hospital. The Perth Master Plumbers and Gasfitters Association says that the need to replace 1200 brass fittings shows the regulatory framework and introduction of new legislation to better control product supply is urgently required. Apparently the fittings do not comply with Australian WaterMark Certification. Interestingly the WaterMark Certification Scheme was again improved only recently and is being progressively implemented from 1 August 2017.
Reports have surfaced that the plumbers on the job were not happy with the fittings they were using, but these reports appear to have been ignored by the previous State Government. The current State Government has committed to replacing the thermostatic mixing valve (TMV) assembly boxes which contain the brass fittings.
There seems to be many instances on this project where products used did not meet relevant standards and if some did meet a standard, why have they now failed. Was the testing rigorously applied ?
The end result of a $1.2 billion facility project is that it is now two years passed the original opening date, staff morale has declined with the delays, and almost 10 per cent of the employees have indicated they are in the process of resigning or seeking opportunities elsewhere.
This story emphasises the need to review State plumbing laws and regulations. Regulations should include provision for stronger compliance to Standards. Only Specially qualified plumbers should install such devices and they should have proper authority to reject suspect or non-compliant products. Thermostatic mixing valves, like back flow prevention valves, must meet Standards and must be installed by specially qualified plumbers.
As these valves or devices are most commonly made out of brass alloys, and are largely imported into Australia, this incident highlights the need for suppliers or distributors, and installers to check quality and compliance on an annual basis to ensure manufacturers are supplying compliant product. The cost of rectifying this problem has run into millions of dollars in lost time, an unusable facility and wasted materials.
Drip Irrigation
Drip Irrigation has long been used in the farming and agricultural industry. This form of irrigation is now growing appreciation as the best option for efficient water wise irrigation due to its ability to source water directly to the plants root system which avoids the loss of water through wind, evaporation and overspray. This also reduces the weeds and fungal diseases.
Drip line irrigation is used on vegetable, fruit trees and non-edible crop. This form of irrigation puts the water supply under the ground with openings where pesticides and other chemicals are utilised to protect the crop from pests and diseases. These chemicals may not be suitable for drinking as heightened by the increase call to ban the use of glyphosate which is sprayed in a liquid form directly at the base of a plant which has the potential to enter the drip line irrigation through back siphonage. This is compared to butterfly sprinkler which are mounted on a post where the opening is above the ground level forming a air gap to help prevent cross connection. I believe the increased use of drip irrigation in Australia has heightened the need for better backflow prevention requirements and introduction of improved standards.
Testing and Maintenance
Under current requirements, for Medium and High Hazard installations, the backflow prevention device must be a registered testable device and must be tested on an annual basis, or be an air gap or break tank registered with the appropriate authority to enable annual inspections. (see AS/NZS 3500.1). This has been the case since about 1990 when previously only new installations were required to be inspected and tested.
Elizabeth Quay in Western Australia – Plumbing Issues
In 2016 the Western Australian Elizabeth Quay water feature revealed a number serious plumbing issues; including wrongly sloping pipes and an absence of critical valves.
Audit and inspection found bacterial contamination in the water sprays of the water playground feature.
Basic Plumbing standards were not met in key facilities such as the plant room. There was a failure to put a non-return device, or backflow prevention device, in one of the water supply lines and there were non-compliances in the way the overflow was connected to the sewer. It didn’t comply with standards. The absence of the non-return device created a risk of highly chlorinated water entering the main water supply to the park.
The overflow pipe into the plant room also had been incorrectly installed. The pipe was designed to prevent the room from flooding by draining excess water into the sewer. That connection did not comply with plumbing standards for venting the gases and for backflow prevention devices. Plumbers had also failed to submit required notices of intention to undertake the work at the site.