What happens when there is no rain?

When there is insufficient water in the storage tank the system automatically switches over and starts to draw water from the mains supply. To the user there is no apparent difference as all taps and water devices will work as normal.

How big is the rain storage tank?

The size of the tank is matched to the catchment capability of the roof, and the consumption requirements of non-potable water in the building.

Is the harvested rainwater clean?

Rainwater supplied through the Envireau system passes through three separate filters that remove all debris and particles, so that the water remains clear.

Does Envireau require maintenance?

Envireau is designed to be a low-maintenance system. Typically, washing off the tank's leaf filter (a 5-minute job with a garden hose) once a quarter is all that is required.

How much water is saved?

The size of your catchment area (usually the roof of the building) and the amount of rainfall in your area will determine how much water is captured. Independently monitored typical domestic installations show that close to all non-potable household requirements were met, saving around 50% on mains water consumption.

Can I drink the water?

Although the rain water is of good quality, we do not recommend it for consumption.

What can I use the water for?

The water harvested is suitable for all non-potable purposes. This includes watering the garden (harvested rainwater is very beneficial to plants and is not subject to the hosepipe bans that affect mains water use), washing the car, flushing the toilet and running the washing machine.

How long will a system last?

The buried components, indefinitely; components such as the control system, pump and filter have an extremely long working life, and are easy to replace should the need arise.

Is it only for new buildings?

Systems are best designed-in from the outset, but can be retrofitted depending upon the accessibility of pipe work.

Can I get any grants or tax allowances for installing a system?

At present there are no funding directly aimed at rainwater harvesting. It does however qualify for 100% capital allowance relief on commercial premises. Click here to find out more...

What is the payback period?

This also varies depending on the amount of rainwater you collect and the cost of water in your area. This can be as low as 2-5 years for commercial systems and between 10-15 years for domestic systems.

How will it affect my domestic appliances?

If you are in a hard water area and install a rainwater harvesting system, white goods, such as your washing machine, often last longer and run more efficiently. Harvested rainwater is soft and so the machine will not build up internal limescale and shorten its lifespan. An additional benefit in hard water areas is that less detergent is required which means less pollutants released into the environment.

Why should I buy one?

Because the system will generate significant environmental benefits through reducing mains water demand and reducing storm water run-off. In addition with water bills expected to rise 10% a year for the next five years then the payback period will be reduced further. Also, control of storm-water run-off is now increasingly a planning issue which rainwater harvesting systems can play an important part in addressing.

In periods of heavy rain, does the system overflow?

A well designed rainharvesting system will allow the tank to overflow two or three times a year, the excess water draining to a soakaway. Overflowing is important as it removes any floating sediment and recharges the trap that prevents drain smells entering the tank.

What happens if it breaks down?

All systems are designed with reliability at the forefront and experience shows that this pays dividends in terms of extremely low failure rates. The systems are also designed to be easily and speedily rectified when the need arises.

Does a system need topping up, and if so, how often?

Envireau is designed to strike the best match between supply and demand; though occasionally the system may need topping up when it has not rained for some time. Generally, the aim is to ensure the tank remains around 50% full (i.e. an ideal balance between having plenty of water to use, and plenty of space to accommodate the next rainfall).

How much does it cost to run the pump?

It typically takes 1.5- 2.0 kWh to pump 1 cubic meter of water (1000 litres). For a typical house using rainwater for WCs, washing machine and the garden, pumping costs are between 5-10p per week.