LRI Landfill
The LRI Landfill is a privately owned mixed municipal solid waste landfill on a 320-acre site.
The 168-acre landfill footprint has the approximate capacity for 29.2 million cubic yards and
will provide for a period of at least 20 years. The landfill footprint comprises of cells, each
is underlain by a state-of-the-art liner and leak detection system and includes other technical
and regulatory design elements which meet and exceed all regulatory requirements. The footprint
was configured to avoid impacts to South Creek and its eastern tributary.
Hours of Operation:
Monday - Friday: 8 to 4:30
Saturday: 8 - 12
Closed: Christmas Day, Thanksgiving Day and New Years Day.
Compost Factory
Safety Guidelines
We are producers of a high quality compost called P.R.E.P. (Pierce County Recycled Earth Products).
It provides extensive capacity for processing organic wastes into products at a competitive price.
The environmental and management controls built into the Compost Factory assure that this compost
facility can be a good neighbor with the community that generate these wastes, and demand these
products.
Hours of Operation:
Daily: 9 - 4:45 Purdy,
Daily: 8 - 5:45 Hidden Valley
Closed: Christmas Day, Thanksgiving Day and New Years Day.
Transfer Station
Safety Guidelines
The Hidden Valley Transfer Station is a fully enclosed and covered, 1½-acre facility allowing
residential customers to unload their garbage free from the weather elements.
The transfer station is one of three designated facilities in Pierce County for residential
garbage drop off. The Hidden Valley Transfer Station is unique because it gives us the ability for
source separation of garbage, allowing us to separate the garbage into items that can be recycled
and garbage for disposal in the landfill.
Material NOT Accepted
Hours of Operation:
Daily: 8 to 5:45
Closed: Christmas Day, Thanksgiving Day and New Years Day.
Gas to Energy Plant
Methane is produced from the bacteria that decompose organic wastes placed in the landfill. Wastes
like food, paper and yard waste are slowly digested by these bacteria in the absence of oxygen giving
off methane, carbon dioxide and moisture. This gas has, in the past, been collected from wells drilled
into the landfill and simply burned in combustion towers. Collection and incineration keeps the odors
down. However this useful natural gas product has the potential for greater uses.
This facility is no longer open. The plant operated from 1999 - 2009 and is now closed.
Leachate
Leachate is generated when the moisture-holding capacity of the refuse in the landfill is exceeded.
Leachate percolates down through the refuse where it is collected on the bottom liner and is directed
to sumps using a series of pipes and trenches.
From the sumps, Leachate is pumped to a 9,200-gallon equalizer tank in the pre-treatment facility.
The tank aerates the Leachate and provides interim storage and flow equalization prior to entering the
chemical treatment unit.
The first step of pre-treatment is to remove metals and solids. The second step uses an aerobic tower
to reduce biological oxygen demand while degrading volatile organic compounds.
From the equalization tank, water is pumped to a three-chamber chemical treatment unit.
• Unit one is a coagulation tank where Ferric Chloride is added so that the
suspended solids are electrically neutralized. This allows the solids to agglomerate together.
• In unit two, sodium hydroxide is added to increase pH above 9.0,
precipitating metals into insoluble hydroxide ions.
• In the third unit, anionic polymer is added, causing the particles to
collide and further agglomerate into floc.
The Leachate then flows into a solids separator, where the floc drops to the bottom. The liquid rises
through an inclined plate separator and into a pH adjustment tank. Sulfuric Acid is added in the adjustment
tank to re-adjust pH to neutral.
The flow then proceeds to a lift tank where it is pumped to the bottom of a bio-tower and is evenly
distributed upward through random packed plastic media. The Leachate is fortified with phosphoric nutrients
to feed the microbes in the bio-tower. The up flowing Leachate comes in contact with a thin microbial film,
which converts the organics to carbon dioxide and water from the top of the bio-tower, Leachate gravity flows
to the effluent tank, and is pumped out of the facility and into the county sewer system.
Hours of Operation:
Daily: 8 to 5:45
Closed: Christmas Day, Thanksgiving Day and New Years Day.
Recycling
Safety Guidelines
The Recycling Center at Hidden Valley provides self-haul customers the opportunity to recycle their sorted
recyclable materials before entering the disposal site. At our outlying sites there are bins available for
customers to recycle their residential recyclables.
The Recycling Center staff provides individual instruction to customers on proper preparation of their
recyclables to maintain high quality and to provide customers with a greater knowledge of the process of
recycling.
Click the following links to get information on LRI's recycling services:
Preparing Your Recyclables
Items Accepted at Hidden Valley
Where to Take Your Recyclables
Hours of Operation:
Daily: 8 to 5:45
Closed: Christmas Day, Thanksgiving Day and New Years Day.
Household Hazardous Waste
Safety Guidelines
The Household Hazardous Waste (HHW) Facility is located inside the Hidden Valley Transfer Station. This is a
Moderate Risk Waste Facility, which only accepts hazardous waste generated by Pierce County Households (no waste
generated by businesses will be accepted). Secured from unauthorized access, this facility provides separate areas
for safe sorting and storage of Flammables, Caustics, Toxics, Oxidizers, and Acids.
Hours of Operation:
Tuesday and Thursday: 8 - 12 and 1 - 5, Closed 12 - 1 for lunch
Closed: Christmas Day, Thanksgiving Day and New Years Day.
Follow the links below for information on
Acceptable Materials
Material NOT Accepted
Preparing items for Transportation
Directions to Facility
Other Links
Please do not leave your Household Hazardous Waste at the Transfer Station when this facility is not open. Hazardous
conditions could occur placing others at risk unnecessarily.