Tag Archives: non potable

How-to, Rainwater Catchment

Is Sole Source Use of Rainwater Collection Legal in King County?

lake-176942_640There has been a great deal of inquiry about sole source use of rainwater collection in King County, causing confusion for the public – as well as for King County public officials. RainBank is currently consulting on four different projects, assisting clients with navigating the system.

A change in Department of Public Health Policy, which is the authority on single source rainwater collection, has been transferred back to the Onsite Sewage System Authority (OSS) of King County Public Health.

There is a section of Title 13 that refers to rainwater collection for single source usage. This authority has jurisdiction over sole source use; any other permitting approval for supplementary source is to be approved by King County Public Health Department’s senior plumbing inspectors. There are plumbing codes that must be met with regard to installation and permitting from KCH plumbing division for any RWC system that is potable or non potable, that is connected to household plumbing.

Below is the section of Title 13 dated November 20, 2013, which refers to sole source usage

D. A rainwater catchment system that serves as the only source of drinking water for a single family residence and that complies with each of the following conditions:

1. The health officer finds that requiring connection of the plumbing system to an approved public water source or to an approved private well would cause undue hardship.

2. Application for a rainwater catchment system source approval shall be submitted for review on forms provided by the health officer. The applicant shall pay to the health officer the rainwater catchment system review fee as specified in the fee schedule, payable after completion of the application review.

3. Application for a rainwater catchment system source approval shall be prepared by any one or more of the following:

a. A professional engineer authorized under a current, valid license to practice in Washington state;

b. An environmental health professional holding a current, valid registration from either the Washington State Environmental Health Association or the National Environmental Health Association;

c. A King County licensed water system designer holding a current, valid license to design water systems in King County; and


d. A rainwater system designer holding a current, valid accreditation from the American Rainwater Catchment System Association.


4. Rainwater catchment system source design shall conform to Part III of Chapter 16 of the Uniform Plumbing Code, 2009 edition, as amended, and shall include, at a minimum, the following information:

a. Estimated daily and weekly and annual demand;


b. Available catchment area and estimated annual rainwater capture;


c. Roofing materials used;

d. Storage capacity of and materials used in the construction of the rainwater catchment system; e. treatment specifications including filtrations and disinfection system specifications; and


f. Operation and maintenance requirements.

5. Composite or shake shingles or other materials determined by the health officer to present a risk of contamination may not be approved or used as roofing materials for a rainwater catchment system source.


6. Before using a rainwater catchment system source, the property owner shall file in the county recorder’s office a notice on title advising that the property is served by a rainwater catchment system and including the following information:

a. The estimated daily, weekly and annual water supply furnished by the rainwater catchment system;

b. That the water supply from the rainwater catchment system may be limited due to variations in rainfall or usage; and

c. That regular maintenance of the treatment system and components is required in order to minimize the risk of consuming contaminated water.

As rainwater collection becomes less of a niche and more mainstream for residential and commercial applications, and with 15 years of design and installation experience, RainBank is the go-to source and your advocate for rainwater collection systems in the Pacific Northwest. Using the form below, contact us today to learn how we can help you with proper system design, installation and consultation through the sometimes confusing permitting requirements for potable, non-potable, sole source and supplementary systems in and around Seattle, Washington state and beyond.

Rainwater Catchment

5 Primary Storage Vessels For Rainwater Collection System

tank below grade w_ concrete foundationAs pervasive drought and aging infrastructure affect our ability to have enough water to meet our household, agricultural and commercial needs, rainwater collection has become a necessary avenue to meet public demand for potable and non-potable water. This post may help you decide among the 5 primary storage vessels when considering a rainwater collection system.

Whether you’re looking for a potable, or non-potable system, storage is always a big decision in the design and installation of a rainwater harvesting system. RainBank Rainwater Systems has experience in installations of buried tanks, plastic above ground tanks and steel tanks to meet its customers’ storage needs.

  1. Buried tanks have less visual impact than that of above ground tanks. Careful planning and engineering is required for this type of installation. Care must be given to surrounding vegetation and tree root systems. Grading and drainage requirements must be met so impact is reduced.
  2. Steel tanks generally can have increased volume and are usually constructed in more of a rural environment. Steel tanks require an engineered slab and must meet seismic requirements. Many find that the industrial look is aesthetically pleasing.
  3. Plastic tanks are the most cost effective and come in many sizes from 50 gallons to 10,000 gallons. Multiple tanks can be manifolded together. While most are guaranteed for UV protection, shading from the sun will increase longevity of the tank.
  4. Slimline tanks offer a compact install for the urban customer, requiring little area for storage. They can be connected together to increase volume.
  5. Cement vault storage under the dwelling can be achieved with proper engineering. This type of storage allows a large volume with no visual impact or area used up for the cistern other than below the structure itself. Care must be given structurally, as well as moisture and condensation concerns need to addressed.

With more than 15 years designing and installing rainwater collection systems in Washington, Oregon, and other states, RainBank Rainwater Systems has the experience, knowledge, and engineering to get the job done right the first time.

This is a throwback Thursday blog post, originally published under the title Choose Right Type of Storage For Water System at RainBank.info

Rainwater Harvesting Education, Sustainability

Where Can You Learn About Rainwater Harvesting?

The American Rainwater Catchment Systems Association (ARCSA) is a rainwater harvesting industry membership organization with a broad range of professionals working in private, city, state, and federal government, academia, designers, installers, manufacturers and suppliers of rainwater harvesting equipment, consultants, and individuals interested in preserving, growing and supporting sustainability through rainwater collection.

arcsalogoThe mission of The American Rainwater Catchment Systems Association is to promote sustainable rainwater harvesting practices to help solve potable, non-potable, stormwater and energy challenges throughout the world.

In 1994, Dr. Hari J. Krishna of Austin, Texas founded the 501(c)(3) non-profit American Rainwater Catchment Systems Association (ARCSA) to bring renewed attention to the ancient practice of rainwater harvesting. For thousands of years collecting rainwater was a common method for providing water, but over the last century, wells and municipal water supplies took over as primary water sources. The diminishing supply of fresh water in wells and aquifers, concerns of quality and population growth are among the top reasons for the resurgence of rainwater catchment. The American Rainwater Catchment Systems Association (ARCSA) was created to promote sustainable rainwater harvesting practices throughout the United States and the world.  Read more.

ARCSA is involved in efforts including:

  • Favorable regulatory atmosphere
  • Educating professionals and the public regarding safe rainwater design, installation and maintenance practices
  • Community outreach education through a volunteer board of directors, augmented by regional directors located in various parts of the United States as well as in Australia, New Zealand, Canada and Europe

RainBank Rainwater Systems president Ken Blair is lifetime ARCSA member, ARCSA accredited Professional, ARCSA Systems Inspector, and ARCSA Northwest regional rep. Ken is a available for ARCSA workshops for interested parties as well as local governmental agencies, engineering and architectural firms. Contact Ken using the form below for more information about a workshop for your agency or group.