Category Archives: Rainwater Catchment

Rainwater Catchment, Rainwater Harvesting Education

ARCSA Leadership’s Sound Business Practices


Ocean waves crashing against rocky shore with splash.As we’ve shared in the past, the mission of The American Rainwater Catchment Systems Association (ARCSA) is to promote sustainable rainwater harvesting practices to help solve potable, non-potable, stormwater and energy challenges throughout the world.

Let’s also congratulate ARCSA for its sound business practices and for having attained theGuideStar ExchangeGoldparticipation level, a testament to the organization’s leadership. This leveldemonstrates ARCSA’s deepcommitment to transparency and accountability.

“Through the national and international work of ARCSA’s Board of Directors and its members, representing government, academia, trade groups, and industry, ARCSA is helping to transform a local and renewable water resource into a global solution for water challenges. This transformation is helping to create jobs, to boost local economies, to improve water quality of receiving waters, and to reduce the dependence on strained municipal clean water supplies.”

You can learn more about ARCSA and rainwater collection by visiting its FAQ page.

ARCSA is engagedin many initiatives for 2015, including its popular annualconference, now in its 11th year, to be held in November in Long Beach CA. This year’s theme is “Beyond The Garden”, and will offervaluable information about residential and commercial rainwater collection ideas, opportunities, and initiatives – for potable and non potable applications.

Infrastructure, Rainwater Catchment

Is Seattle Implementing Rainwater Collection in Stormwater Management Program?


Is Seattle implementing Rainwater Collection as part of its Stormwater Management Program (SWMP)?

Row of rain barrels connected to a gutter system for water collection.SWMP applies to the municipal separate storm sewers owned and operated by the city. SWMP address the National Pollution Discharge Elimination System (NPDES) and is permitted by ecology. Seattle Public Utilities (SPU) is the lead city department responsible for implementing permit coordination in SWMP.

“The City of Seattle is required to develop, implement and enforce a program to prevent and control the impact of stormwater runoff from new development, redevelopment and construction site activities.” (SWMP Jan. 2015)

Part of the “minimum performance requirements” of SWMP is to “incorporate and require Low Impact Development (LID) principles and its Best Management Practices (BMPs).” The Green Stormwater Infrastructure (GSI) is part of the stormwater code and requires that any new construction, commercial or residential, infiltrate runoff. SPU’s “Rainwise Program” offers education to the general public on infiltration of stormwater and rebates of implementation as long as requirements are met.

The city of Seattle Health Department allows rainwater collection for non-potable and potable use.

Unfortunately SWMP does very little to encourage rainwater collection, even though it is promoted by Ecology. The Rainwise Program addresses infiltration, not use of a rainwater system, while rainwater collection and its use offers more advantages than simply infiltrating. The use of collected rainwater for toilet flushing, laundry, and when properly filtered and disinfected, potable use, not only helps mitigate roof runoff,but helps supplement our water supplies.

The demands of our water supplies nationwide are becoming strained and will continue as population growth continues. Costs of expanding and upgrading current water infrastructure will cost billions locally in the next 20 years, while a more proactive approach of a supplemental, decentralized water system addresses both issues of stormwater and water demands while keeping costs down.

While Seattle is addressing stormwater runoff, they are missing the boat on rainwater collection promotion. More information and comments to Seattle City Council links are provided below.

For More Information

Rainwater Catchment, Residential Rainwater Collection

Can I Collect Drinking Water From My Roof in Seattle?

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Seattle skyline featuring the Space Needle under a cloudy sky.Does Seattle allow rainwater collected from the roof to be used for drinking water?

You can have a potable rainwater collection system designed by an engineer, licensed in the state of Washington with experience in RWC, or an ARCSA(American Rainwater Catchment Systems Association) accredited professional. Knowledge and experience are required for potable design in King County. A properly designed filtration and disinfection system can provide quality drinking water. It is the designer and installer’s responsibility to ensure that an adequate system is in place and correctly installed.

After system install has been completed, it is up to the owner or operator to maintain the system to protect users from possible contaminants. Sampling and testing are essential to ensure the system is performing as designed. It is recommended that filtered, disinfected rainwater should be tested annually.

Mountain landscape with a clear blue sky and green forest.A typical filtration/ disinfection system consists of a sediment filter, activated carbon, and ultra violet light and is adequate for achieving potable standards. Adding a 1-micron absolute sediment filter before the UV adds a higher level of endurance of cyst removal. Other possible contaminants can be identified by testing “raw water” before the filtration train and then can be removed by additional filtration. The last device should be an ultra violet light, which must carry a “class A” rating.

Quality drinking water is possible with rainwater collection and is legal in many counties in Washington State, including Seattle. Many are finding the alternative appealing to municipal water supplies, while also helping to reduce stormwater runoff. Seattle Public Health encourages the practice of rainwater collection, as does Washington State Department of Ecology.