The Volunteer Park Sustainability Coalition was awarded a $25,000 Small and Simple Neighborhood Matching Fund Grant by the Seattle Department of Neighborhoods on November 19, 2015.
The grant will fund a park-wide feasibility study to determine sustainable improvement related to water usage as outlined in a preliminary Sustainability Improvement Measures report executed by Young | Architects LLC.
The Volunteer Park Sustainability Coalition is composed of partner organizations within Volunteer Park including the Friends of the Conservatory, The Volunteer Park Trust, and the Asian Art Museum.
The feasibility study will build on water-usage-related areas in the preliminary report including:
Storm Water Management
The storm water system for Volunteer Park, that includes the roads and buildings, captures rainwater in gutters and catch basins, and is piped separately from sanitary sewer through the Park. The storm water leads to a detention tank in the NW area of the Park next to the lower greenhouse. From the detention tank the storm water then merges with the sanitary system into a combined sewer.
About two-thirds of Seattle is served by a combined sewer system, which was designed to carry sewage and storm water runoff in a single pipe.
Under dry weather conditions all sewage flows to the treatment plant. During wet weather conditions, however, storm water runoff is considerable and can cause the capacity of the combined sewer system to be exceeded. When this mixture of storm water (about 90%) and raw sewage exceed the pipe’s capacity, it results in a combined sewer overflow directly into Puget Sound. This is very harmful to the environment, and eliminating CSO’s (Combined Sewer Overflows) is a goal of the City and Parks. With 48 acres of Park space, we see an opportunity to treat storm water on site utilizing Low Impact Development strategies and eliminate over 2 million gallons of storm water runoff from the CSO each year.
- Rainwater harvesting from glass rooftops and reuse for toilet flushing and indoor irrigation at the Conservatory and Greenhouses.
- Rain harvest tanks and cisterns.
- Bio-retention / infiltration in the form of bio-swales, raingardens or infiltration trenches.
- Storm water storage for irrigation utilizing the existing reservoir infrastructure and pump house.
- Storm water treatment and detention upgrades.
- Cover outdoor compost, mulch, and soils bins, and provide containment per code.
Water Efficient Landscaping
Volunteer Park is a Registered Historic Landmark, and the Olmsted planting plan is covered in the landmark designation. The Park consumes over 7 million gallons of water for irrigation purposes alone on average, the equivalent use of about 230 people.
The Volunteer Park Draft VMP (Vegetation Management Plan) from 2005 addresses both historic aspects of the park planting and the inclusion of northwest native species that will be more drought tolerant and require less watering.
- Repair the leaking irrigation system. (Currently in progress)
- Improve irrigation system with proper irrigation zones for the various plant species.
- Continue with work parties to remove noxious weeds, and plant appropriate species following the draft VMP.
- Deduct meter. Now that utility billing has changed for Parks citywide to be charged for water consumed and water sent down the sewer system, a deduct meter will measure the water used for irrigation purposes and deduct that from the sewer portion of the bill. The Park irrigation appears to be deducted, but further opportunities in the greenhouses may still exist.
Innovative Waste-Water Technologies
Waste water, both grey and black, is sent down the drain throughout Volunteer Park to the sanitary treatment facility.
There are many planned improvements throughout the park and some of the structures involved have restrooms. These new facilities whether public or not, could use innovative wastewater technologies such as composting toilets or even a waste water bio-treatment pond. With 48 acres of space, there could be spaces in the park for a waste water treatment pond, or the spreading of compost in specified planting areas.
- New restroom facilities should explore the implementation of composting toilets to decide if they make sense for proposed improvements.
- Explore the idea of a living machine, or on site bio-treatment pond.
Water Use Reduction
The primary water use in Volunteer Park is for irrigation. The remaining facilities consume a small fraction of the water resources in the park. Opportunity
The Volunteer Park Trust has initiated a project to improve the existing irrigation system for the park. The irrigation system is old, leaking, and needs repairs to the existing plumbing system, and relocation of sprinkler heads to accommodate growing and changing plantings. Innovative wastewater technologies consume less water to operate.
- Repair the existing irrigation system
- Improve the irrigation system by adding and relocating sprinkler heads
- Review during design use of composting toilets
- Specifying low flow fixtures
Volunteer Park uses potable water from the Cedar River and Tolt River Watersheds for the domestic and irrigation needs. Melting snow and ice are gathered and stored in pool reservoirs created by dams. The water is released and then diverted into pipelines and pumped to treatment facilities. The majority of water used in the park is for irrigation purposes.
Typically, rainwater harvesting in Seattle provides too much water in the wet season and not enough in the dry season. However, inside the Conservatory and the greenhouses, watering takes place year round providing a use for captured rainwater. Additionally, the indoor plantings, particularly the exotic and warm climate horticultural species that compose most of the Conservatory and greenhouse plant collection prefer, rainwater to treated water.
- Collect rainwater from roof tops, particularly the glass roofs of the Conservatory and greenhouses.
- Utilize the recently installed storm-water system for the Conservatory to collect rainwater in cisterns for irrigation.
- Collect rainwater from the reservoir, the single largest impervious surface, and use as a storage device. The reservoir has an existing pump house that can be used to deliver water for irrigation throughout the park.
Grey Water Re-Use
The lower greenhouse facility has showers, laundry, and sinks that drain directly to the sanitary sewer. The Wading pool in the NE corner of the Park, uses about 1.7 million gallons of water each year (based on data provided by Parks). The pool is filled daily in the summer months and then drained each night directly to the sanitary sewer.
Grey water reuse is now legal in Washington state for subsurface irrigation. Since wading pool use coincides with the dry summer months, the drained water could serve as needed irrigation. Additionally, the water costs the city over $5 per CCF (centum cubic feet) and over $11 per CCF for the sewer. Reuse of this water could save nearly $30,000 per year on sewer alone and another $10,000 on water for irrigation each year.
- Utilize the pump in the clothes washer for subsurface irrigation in demonstration garden.
- Route water drained from the wading pool to a cistern, where water my be pumped for sub-surface irrigation in the Park.
- Utilize the wading pool as a rainwater harvesting device in winter months and use collected rainwater for irrigation in the Conservatory.
- Install a pool filtration system to recirculate and reuse water for the wading pool.
For more information about the Volunteer Park Sustainability Coalition, contact firstname.lastname@example.org or 206.322.4112.