Category Archives: Potable

Storey’s Water Tower

A designed rainwater collection system for the ages, Storey’s water tower was designed and built as a sole source rainwater collection system for a household in the San Juan Islands of Washington State. The Storeys constructed a home on an isthmus with panoramic water views facing either side of the house. While spectacular, there was little chance of drilling a potable well, since water was only 150 feet from either side of the house. The total square foot of the house and shop would yield approximately 900 gallons per inch of rainfall.

The water is screened as it enters the roof gutter system, then finer screening and sedimentation occurs before gravity feeding into the sump tank. A float switch will activate a sump pump to convey water to this magnificent water tower, with a office space on top, to enjoy those views.

The system is pressurized with a with a centrifugal pump and pressure tank which feeds a 5-micron sediment filter followed by carbon filtration. The Story’s were pleased with their new system even though “It lacks mineral value, but that’s alright, as long as it keeps one mineral out – salt water.”, said Mrs. Storey. That was 1977!

Coincidentally, I visited this house in the mid-eighties, before I had knowledge of rainwater collection. I was fascinated with the concept and impressed with the design and craftsmanship. The thought of a self-sustaining water system, when no other source was available, made perfect sense. The simple mechanics of prescreening, pre-filtering, and pressurized conveyance is the basis of best practices still used today.

I had an opportunity last month to conduct an inspection of this system for the new owners and was thrilled to see. with a few improvements and UV sterilization, this system is still producing a sustainable source of potable water, and can be expected to continue for another forty years.

Potable Rainwater Collection Adopted in Snohomish County

Snohomish County adopts rainwater collection for potable usage for single family residence.

In September 2015, we published a post recommending that both Snohomish and Pierce Counties adopt rainwater collection for residential potable usage. The necessity for adoption was presented considering a 30% reduction in water availability was predicted in the next 35 years.

The Seattle Times reported about the Hirst Decision and its effects in rural development in many counties throughout Washington. These counties should follow the lead of counties before them by providing a sustainable, viable water rights decision on single family residences that allows for potable rainwater systems. It is the only fair decision to be made.

We congratulate Snohomish County for having a progressive approach to water conservation.  Adding to our list of firsts, this week, we will install the first potable residential system in Wahkiakum County upon their acceptance of a RainBank Rainwater Systems design.

RainBank Rainwater Systems has been Designing and installing Rainwater collection for residential potable usage for over 16 years. We will continue to promote, advise, and educate rainwater collection as a viable, sustainable water source in all counties in Washington State.

We look forward to helping those in Snohomish County achieve water rights for potable usage using rainwater collection.

Poorly Designed Rainwater Harvesting Systems

Poorly designed and maintained rainwater harvesting systems can be more than unpleasant.

As many others did, I built a house in the Puna district of the Big Island of Hawaii in the 1980’s. The inexpensive properties of the subdivisions above Hilo provided an opportunity for home ownership to those who could not otherwise afford to build. The subdivisions were created in the 1960’s and 70’s as agricultural, with little infrastructure, certainly no water source. As everyone else did, I built my own rainwater catchment system, designed based on what everyone else was doing. The county provided “city water” stops along Kamehameha Highway, for drinking water for those on rainwater catchment. All other household water use was provided by the catchment system with little filtering and no real disinfection. UV disinfection was not available for small water systems at that time. 

Many systems were owner built and consisted of a “pool boy” – an above ground swimming pool with a non potable liner. There were some corrugated steel and a few cement or wooden tanks. Many of the roofs were asphalt shingle, causing a bit of a sheen on the water surface during the hot day. A sediment filter prior to the pump was the typical filtration train and, as mentioned, no disinfection. But, no one was drinking it as far as I knew. 

For decades there were no regulations for rainwater catchment systems in Hawaii. Systems were built with not much consideration of public health. Essentially, a large community with no oversight to standards or safe practices. Now, many of these antiquated systems are being contaminated by slugs and snails which have been found to carry “rat lungworm parasite”, a potentially devastating disease. Please see below article.

Water Catchment Systems Need to be Properly Maintained

Rainwater catchment can be a safe, viable alternative to ground water “IF” proper best practices are followed. The industry has grown considerably, along with most states having some type of regulations and permitting.

ARCSA/ASPE/ANSI 63 has been adopted as code by most municipalities that allow rainwater collection for potable use. ARCSA Accredited Professionals are trained and must participate in continuing education in order to keep their accreditation. Designs for permitting are being submitted to Health Departments for plans review. Inspections by county plumbing inspectors during construction of systems is common with bacterial sampling required by some.

It is not the 70s and 80s any longer and rainwater catchment for potable use has hit an all time high here in Washington State. Systems are being designed and installed by professionals that have the training and experience needed for the well-being of their customers. Check with your contractor to be sure they are ARCSA Accredited and know the code requirements. By doing so, you will be assuring that your water source is safe for you and your family.