CITY OF SNOQUALMIE
PUBLIC WORKS
Phone: 425-831-4919
38624 SE River Street
PO Box 987
Snoqualmie, WA 98065
www.ci.snoqualmie.wa.us
[email protected]
Falls-Grow
Soil Nutrients from Snoqualmie
The following information was provided by the City of Snoqualmie Public Works Department and
Water Reclamation Facility to the State of Washington Department of Ecology. The city’s biosolids
received a Class “EQ” (Exceptional Quality) rating.
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Falls-Grow signals the City of Snoqualmie Public Works Department’s commitment to recycle and
reuse for the benefit of the community. Many residents and industry experts understand the
importance of maintaining a sustainable community by reusing valuable resources. The City’s state
of the art water reclamation plant produces reclaim water for use in parks, public right of way, and
the golf course. Snoqualmie’s Water Reclamation facility, with the addition of the Fall-Grow biosolids
production, is capable of recapturing wasted nutrients and transforming them into a slow release
nutrient rich organic soil enhancer.
Falls-Grow is a nutrient-rich organic material resulting from the treatment of sewage sludge. When
treated and processed to the highest levels attainable, treatment plant solids become biosolids which
can be safely recycled and applied as nutrient rich soil enhancer to sustainably improve and maintain
productive soils and stimulate plant growth. To ensure maximum acceptability and safety, the
Snoqualmie Water Reclamation Facility treats solids to the most stringent standards imposed by the
EPA and Ecology for “Exceptional Quality” (EQ) biosolids. In order to achieve this “Exceptional
Quality” standard, the City of Snoqualmie’s WRF uses an indirect heat drying system. Through our
biosolids management practices, the solid residue from wastewater treatment is processed to
eliminate pathogens, forming a safe, beneficial product. Falls-Grow contains no detectible levels of
pathogens, and meets strict vector attraction reduction requirements and low level metals limits.
The use of “EQ” biosolids as a nutrient addition and soil enhancer for both residential and
commercial use is permitted by the United States Environmental Protection Agency (EPA) and
Washington State Dept of Ecology. The EPA and Ecology promote biosolids based soil amendments
as environmentally safe and beneficial for plant growth.
Organic nitrogen and phosphorous found in products like Falls-Grow are used efficiently by crops
because these nutrients are released slowly throughout the growing season. This enables the crop to
absorb the nutrients during growth as needed. This efficiency reduces the chance of groundwater
pollution from nitrogen and phosphorous and thus helps reduce the amount of excess nutrients
entering our streams and rivers.
Farmers and master gardeners have long understood the benefits of recycling to rebuild soils and add
nutrients to soils from reclaimed materials around the garden and farm. To take advantage and
promote recycling and reuse, the City of Snoqualmie now manufactures Falls-Grow. Falls-Grow is
made from material that would otherwise be wasted and is now available to the community for use in
golf courses, parks, lawns, gardens, and pea patches, to be used as a nutrient rich soil enhancer.
With the addition of our biosolids manufacturing process, it is now possible to offer free product to
the public for a limited time.
Spreads with Conventional Equipment
Heat dried biosolids are easy to handle. The material is dirt like in appearance. It spreads with
conventional equipment such as home push type fertilizer spreaders, farm manure and fertilizer
spreaders, and broadcast spreaders.
Concentrated Organic Source
Heat dried biosolids return to the soil a high-grade organic matrix that enhances the soil/food web.
This means that Class “EQ” biosolids can enhance the very nature of the soil over time, which is an
attribute lacking with chemical fertilizers. Each application of biosolids not only provides nitrogen and
micronutrients but also adds needed organic mass to replace that which is being constantly depleted
and absorbed.
Improves Soil Tilth and Hydraulics
Biosolids have the ability to improve the ability of the soil to promote plant growth through improved
soil mechanics. This is reflected in better soil permeability while at the same time adding to the soil’s
ability to retain moisture. The effect over time is a soil which needs less watering and which supports
better plant rooting.
Slow Release- No Burn Nitrogen
The slow release organic nitrogen in biosolids means that it will not burn the ground like chemical
fertilizers can, even if somewhat over applied. Its slow release also means that the nutrients are
available to the plants during a longer growth cycle.
Application Principals
“EQ” biosolids can be used as a nutrient rich soil amendment for the home gardener or landscaper.
It should be used according to agronomic loading rates specific for each particular site and use. The
agronomic rate is best determined by contact with local horticulturalists, county extension agencies
and area fertilizer providers and users. The rate will be different for different uses and different
areas. A general guide for typical heat dried biosolids at 5% nitrogen might approximate the
following:
As a top dressing use about 25 pounds per 1,000 square feet.
As a shrubbery food, use about one cup for small bushes, two for medium sized and three
for large ones.
As a potted plant food, use a handful for each medium sized plant.
For new seeded lawns and sod applications use a little less than the top dressing rate (about
20 pounds per 1,000 square feet).
To restore old and worked out gardens- work about 10-20 pounds per 100 square feet into
the top several inches of the soil. This will replace chemical fertilizers.
Trees- use 2 pounds per inch of diameter spread evenly out to the drip line (the “shade” at
noon).
Nutrient levels
6.0% Nitrogen
2.0% Phosphorus
0.5% Potassium
Super Sack Weight
2000 lbs
2000 lbs
2000 lbs
Nutrients
0.058521089
0.004537273
0.020136364
Total Nutrients per Sack
117 lbs. of Nitrogen (N)
40 lbs. of Phosphorous (P)
9 lbs. of Potassium (K)
HANDLING
Heat dried biosolids, when dried to 90% solids are stable. When put on the soil, the millions of
microbes in the soil will take over the nutrient incorporation chemistry and allow the plants growing
in the soil to use the nutrients efficiently. This process significantly reduces any odor generation from
the biosolids once they are re-wet. In short, the soil microbes rapidly predominate and air borne spoil
odor forming bacteria will not linger. This is because the soil bacteria are plentiful, already acclimated
and able to quickly cover the surface area of the dried biosolids.
The dried biosolids will become difficult to handle in bulk when they are re-wetted. For this reason,
dried biosolids should be kept dry until use. The dry biosolids should then be put down on the ground
or mixed with a soil to be used immediately, in both cases at the correct agronomic rate.