Healthy rainwater tanks

Details

Last Updated on Friday, 07 December 2012 21:53

Toowoomba Regional Council supports rainwater harvesting. However, Council does not suggest that tank water replace an available town water supply for drinking purposes because there is no guarantee that every resident installs, cleans and maintains rainwater tanks correctly to ensure safe drinking water.

Householder Maintenance of Rainwater tanks

High quality tank water is dependant on the owner’s maintenance of a healthy tank.  Proper maintenance involves the cleaning of gutters and downpipes and checking for mosquito and vermin control. Tank installation could include a “first flush” system to divert the initial scour of dirty rainwater away from the tank.

Read more: Healthy rainwater tanks

Tank maintenance

Details

Last Updated on Friday, 07 December 2012 21:53

To help ensure the integrity of your  rainwater tank, the quality of the collected rainwater, and the safety of the community against disease, follow this simple maintenance checklist.

Monthly inspection   This should involve checking the tank strainer and tank overflow screen for any breakage where mosquitoes can enter. Clean them monthly throughout summer wet season and three monthly from Autumn to Spring.

Three monthly inspection  Check and clean first flush devices, and leaf guards on rainheads. Check the roof and clean gutters of plant material and other potential contaminates. If large amounts are found, then inspection and cleaning should be done more frequently, especially after heavy rainstorms. Prune overhanging tree branches and foliage. 

Read more: Tank maintenance

What to consider when retrofitting a tank

Details

Last Updated on Friday, 07 December 2012 21:53

Current State Government legislation (Qld Development Code 4.2) and theToowoomba Regional Planning Scheme outline requirements for mandatory tanks to be fitted to new residential, commercial or industrial buildings. Refer to the related Plumbing information sheet INFO 26 Requirements for Installation of Rainwater Tanks.

However, when retrofitting to an older existing home there are several things you need to consider (refer to the related document below for a summary of these points).

What size tank should I buy?

When planning to install a rainwater tank, you should determine:

• The intended use of rainwater
• Volume of water needed for these uses
• Roof area supplying the tank

Using Toowoomba rainfall records, a 10,000 litre (2,200 gallon) rainwater tank internally connected to the toilet and washing machine could be expected to generally supply 20-30% of the average daily water needs for a typical household. Using a 22,000 litre tank (5,000 gallon) would increase this figure to 30-40%.

How much water will the tank collect?

Read more: What to consider when retrofitting a tank

Tank water safeguards

Details

Last Updated on Friday, 07 December 2012 21:53

When installing a rainwater tank attaching several simple devices may assist in keeping the tank water quality in reasonable condition.

Gutter guards prevent leaf litter entering the tank

If leaf litter enters the gutter, this debris may accumulate and block the rainhead or inlet screen causing uncontrolled overflow and reduce the amount of rainwater collected.

Rainhead diverts leaves

Installing a screened downpipe rainhead on each down pipe just below the gutter sheds leaves, preventing them from entering the tank. Self cleaning types are recommended.

First flush diverter redirects the first polluted flow

Pollutants and debris washing off the roof in the first runoff (20 litres/100 sq.m.) are redirected to the overflow drainage system, protecting the tank from excessive collection of sludge and subsequent organic and chemical contamination.  First flush devices need to be cleaned regularly to function well.

Read more: Tank water safeguards