How To Keep Stored Rainwater Clean

fresh-839260_640Compared to surface water, rainwater is relatively clean to begin with. It is what rainwater comes in contact with that requires attention. Dust, pollen, organic materials, such as leaves and pine needles greatly affect the quality of stored rainwater.

Filtering out this debris upstream from storage should be included in your rainwater harvesting system. A high quality gutter screen is recommended as a first line of defense against debris, while it also keeps your gutters clean.

The use of downspout filters, or vortex filters, will improve the quality of your stored water by filtering and aerating rainWFF100-Vortex Filter_RainBankwater before it enters the storage tank. Removal of large particulate along with aeration greatly reduces the amount of harmful bacteria entering the storage tank. A downspout filter or vortex filter acts as first flush device and aerates the water and will not freeze as other first flush devices.

A smoothing inlet installed inside the bottom of the tank distributes the incoming water horizontally and prevents stirring up the sediments while aerating the water as it enters the tank. Aeration happens with each collection cycle and helps keep a healthy bio film at the bottom of the tank. There are beneficial microbes in the sediment that actually eat bacteria as they sink to the bottom. A healthily maintained bio film enhances the water quality in storage.

To prevent backup in the system during heavy rains, the storage tank should always include an overflow device. The overflow device allows water to overflow, but protects water quality in the storage tank with back flow prevention and vermin protection while also providing a skimming during overflow of buoyant debris, such as pollen, on the water surface.

Finally, a floating suction ensures the water being provided to the pressure pump and filtration is the cleanest water from the storage tank. Since all harvested rainwater is filtered before entering the tank, the floating filter should never clog, but will instead take water from just below the surface. Water at this depth is of the highest quality in the tank, because any particulate that enters the tank either floats on the surface or settles to the bottom. The floating filter acts as an uptake point for the pump than a filter; thus, the floating filter should never require maintenance.

RainBank Rainwater Systems is a dealer of Wisy and the Four Step System to ensure quality, collected rainwater.

Ken Blair
A rainwater collection systems designer and consultant, Ken has designed and installed residential and commercial systems, primarily in the northwest United States for more than 10 years and, in 2014, began consulting and managing builds in other states. Ken is an accredited ARCSA Professional Designer / Installer and Life Member, the Northwest Regional ARCSA representative and advisor to its education committee and is available to speak about Rainwater Collection Systems design and builds.

Ken is a United States Navy veteran, having served on active duty during the Vietnam War era.

A career entrepreneur, Ken created a new business focus with a commercial dive company in Hawaii in the mid 1980′s to respond to and clean up oil spills, oil spill equipment training, service and maintenance for the oil co-op service industry. Ken is passionate about having a positive impact on the environment and is also a founding director of BANK-ON-RAIN (2011-2014), whose mission is to create grassroots solutions for rainwater collection for consumption and agriculture in developing areas of the planet.

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