Tag Archives: featured

Commercial Rainwater Harvesting, Rainwater Catchment

Commercial Uses for Rainwater Collection


Cherry Valley Dairy building with a visible sign.RainBank Rainwater Systems has been retained to design and build a rainwater collection system for Cherry Valley Dairyin Duvall, WA. The goal is to collect and treat enough rainwater to mitigate the farm’s city water usage by 100%. Currently the farm uses over 7,500 gallons monthly for watering the livestock and milking equipment wash down. With over 12,000 square feet of roof area and approximately 36 inches of annual rainfall, that’s over 269,000 of available rainwater – more than enough to supply the farm’s usage. (Click to see more aboutCherry Valley Dairyon Facebook and while you’re there, don’t forget to like RainBankon Facebook, too!)

RainBank is pleased to see more innovative uses of rainwater collection in the Pacific Northwest. As the economy is growing again, businesses are looking for ways to save on operating costs. With large roof areas and high use operations such as the dairy, commercial customers are recognizing that a return on investment can be achieved in a realistic time frame. Their customers appreciate the “echo friendly” approach to the production of their goods and products.

RainBank is looking forward to working with Cherry Valley Dairy and supports their business approach to be the first in the area to use rainwater collection as their water source.

How-to, Rainwater Catchment

Ultraviolet Light Disinfection For Rainwater Harvesting

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This is the final post on “How to Build a Rainwater Collection System. Click to see partsone,two,three,four,five,six,sevenand eightof “How to Build a Rainwater Collection System”.

There will be additional posts that elaborate on some key points in the near future, so stay tuned (click the box below to receive new posts in your email inbox).

Close-up of a glowing blue neon tube light with metal fixtures.The final stage of treatment for a potable rainwater collection system is ultraviolet light disinfection (UV). Effectiveness of the UV system is determined bya few factors. First, pre-filtration, which includes a sediment filter and a carbon filter that need to be upstream of the UV. This will help ensure the clarity of water entering the UV chamber, enabling the UV rays to penetrate the water stream.

When UV energy is absorbed by the reproductive mechanisms of bacteria and viruses, the genetic material is “rearranged” and can no longer reproduce, with risk of disease eliminated.

There are 2 classifications of UV light determined by the dosage of the UV light itself, and a class “A” UV is the only class recommended for disinfection of rainwater collected from a rooftop.

The American Water Works Associationdescribes a class A ultraviolet system as an effective method of disinfection for water that is not determined safe to drink. A class B ultraviolet system is only effective for water already deemed safe to drink – such as a water source already treated with chlorine.

An alarm and or solenoid valve for system fail safe is always a good idea to include with your UV system. This method will shut down the system or sound an alarm if a sensor determines the water turbidity (clarity) is not sufficient for proper UV absorption.

Ultraviolet light is a natural, cost effective environmentally safe method of disinfecting drinking water as long as it is properly maintained and the bulb is changed according to manufacturer’s recommendations.

How-to, Rainwater Harvesting Education

What is the Key to Having a Safe Source of Water From Your Rainwater Collection System?


This is Part 8 in the series. Click to see partsone,two,three,four, five,sixand sevenof “How to Build a Rainwater Collection System”.

Two large rolls of plastic wrap, one white and one brown.Whether potable (drinking water) or non potable (irrigation, toilet, laundry), filtration and disinfection are key to having a clean and safe source of water from your rainwater collection system. Of course, pre-screening the rainwater before it enters the storage tank is essential as discussed in part 3of this series. Filtration for a non potable irrigation system consists of a sediment filter after the pressure pump.

A 5 micron poly sediment cartridge filter will keep particles from clogging your soaker hoses and emitters. Cartridge filters come in various sizes. Smaller 2″x 8″ filters will need to be changed more often. Whereas larger cartridge filters, if not used regularly can hold bacteria and develop a bad odor. Generally for average irrigation needs, a 4″ x 10″ 5 micron poly sediment cartridge filter will do the job. Be sure to remove and discard the cartridge after the watering season so filter does not go sour during the non-use months.

Two large rolls of plastic wrap, one white and one brown.For non potable, toilet flushing and laundry facility systems,it is recommended to add a 10 Micron carbon filter. This filter will remove organics and inorganics, color and odor from you stored rainwater. By having the cheaper 5 micron sediment filter upstream of the more expensive 10 micron carbon filter you will save money by not fouling the carbon filter with particulate less than 5 Microns. Depending on how much use for this type of system, a 4″ x 20″ cartridge will mean less changing of filtration. If the system is to be shut down for a lengthy period, it is recommended that filter cartridges be removed so water will not become septic by decaying bacteria.

Lastly if a potable system is desired, a 1 micron absolute filter that is certified NSF 61 for cyst removal is recommended downstream from the sediment and carbon filter. A 1 micron absolute sediment filter will remove cysts but is not intended to be the final disinfection for potable water. Again, a 4″ x 20″ cartridge will mean less change outs of the filter. A 1 micron absolute filter is intended to be used in addition to UV sterilization. With the UV to be the final element in the treatment system. We will discuss UV disinfection in part 9 of this series (check the box below to receive new posts via email).

Regular inspection and maintenance of your filtration system will insure safe, and proper operation of your potable and non potable rainwater catchment system.