Water Harvesting System Tank
The OASISTM rain water harvesting storage tanks are one piece tanks with a 30 year warranty when installed correctly.
A one piece construction ensures that there is no possibility of water leaking either in or out of the water harvesting tank itself. This is a potential problem for some rainwater harvesting systems that use sectional water storage tanks. These must be fitted and sealed together properly, in accordance with the manufacturers assembly instructions, in order to be watertight.
Should any leaks develop, the warranty can be voided if the manufacturer can find fault with the tank assembly. Water leaks can be difficult to detect and cannot be sealed while the tank is underground.
A further problem with polyethylene tanks is that no commercial adhesive will bond with the plastic. Plastic welding is the only way to effectively repair polyethylene.
The OASIS 30 year rain water harvesting tank warranty is the longest of any manufacturer.
Mains Water Backup for your Harvesting System- don't risk Legionnaires Disease
The method of supplying mains water during a dry spell is the most important part of Rain Water Harvesting design.
The majority of rainwater harvesting systems will switch to providing mains water straight to appliances when the water in the harvesting tank drops below a certain level. This results in a potential heath risk as there will still be some water remaining in the tank. Rain water is not clean and will be contaminated with bird faeces, rotting vegetation and other material from the roof and gutters. As a result the water in the storage tank will contain bacteria. If mains water is provided directly to appliances then the residual water in the tank will start to stagnate and the bacterial population in the water can rise. When the tank is refilled with rain water and this is provided to appliances, the bacteria in the water can come into contact with people and potentially cause illness. This is usually from an aerosol (toilet flush, tap, hosepipe etc) which can cover skin, nose, mouth, toothbrushes, towels etc in bacteria. An aerosol is the perfect method of transmission for many bacteria, including the very dangerous Legionnaires Disease.
The OASIS rain water harvesting system is designed to eliminate potential risks to health as much as possible. One way it achieves this is to always draw water from the harvesting tank and NEVER revert to mains water direct from the water main.
When the water in the tank falls below a predetermined level, the OASIS control panel will provide a small volume of mains water to the rainwater harvesting tank. This ensures that the water in the tank will never stagnate as it is constantly being replenished. It also has the advantage of utilising the chlorine in mains water as an antibacterial to partially sterilise the water harvesting tank.
OASIS Control Panel
The control panel is the heart of the OASIS rain water harvesting system. The key principles behind its design are simplicity and mechanisms to reduce potential risks to health. The control panel allows the OASIS Rain Water Harvesting system to be installed in any configuration: House and/or garden system: Direct and/or indirect supply of water
There is no option to buy an OASIS Rainwater Harvesting system with cheaper, inferior components.
Every part of the harvesting system is made to a very high standard and serves a specific purpose.
Water Harvesting Filters
The type and quality of water filter is paramount for any rain water harvesting system. Some water filters, such as vortex filters, are not suitable for use in the UK as they require a large volume of water to be passed through the filter in one go, such as a monsoon or heavy down pour. In drizzly UK conditions these water filters are very inefficient. The rain water harvesting filters used in the OASIS rainwater harvesting system are designed for northern European conditions and to give as great a water yield as possible.
For roof areas of up to 150m2 the rain water harvesting filter is located in the top of the tank. For ease of maintenance rain water filters for larger roof areas are located adjacent to the water storage tank.
Pump Types and Options
The type of water pump and its location are significant for any rain water harvesting system.
OASIS Rain Water Harvesters only use pumps with stainless steel internal components and all pumps are located in the storage tank. This is done for several reasons
- Stainless steel components are more reliable and longer lasting than their plastic alternatives.
- Pumps are designed to pump, NOT draw.
- It creates a silent system.
- When a pump is located externally form the storage tank, such as a utility room, then the pump must first draw water from the storage tank and then pump it around the building/garden.
- The distance a pump can suck water is limited and so the distance the storage tank can be from the building is limited causing problems on some sites. To overcome these problems an additional pump is sometimes required between the storage tank and the original pump. This doubles the running, maintenance and replacements cost.
OASIS Rainwater Harvesters site the pump in the tank to create a more efficient and flexible system.
Direct / Indirect water supply system
Direct rain water pump systems pump water straight from the tank to the appliances. Indirect rain water pump systems provide water to a header tank at the top of the building and water is supplied by gravity from the header tank to the appliances.
The OASIS control panel allows the OASIS rain water harvesting system to be configured to supply water directly, indirectly or by a combination of both methods. By doing so the OASIS system suits every building and lifestyle.
