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Biosolid Uses

Bio solids Distribution chart

 

Strict quality control procedures and regulatory compliance with federal, state, and local laws are followed for the production and use of biosolids. Farmers use some of the biosolids as a soil amendment and fertilizing material and some are mixed with green materials and other organics to produce compost. LA Sanitation (LASAN) currently manages it biosolids through land application and composting. LASAN is also investigating a new and innovative option, deep well injection of biosolids to produce renewable energy. Various technologies are being developed and proposals are continuously being reviewed by staff.



 

COMPOSTING
 

 

 Biosolids Composting Image

 

Composting is the process by which organic materials such as biosolids are decomposed into a nutrient-rich soil conditioner. There are three primary composting methods, all of which produce a safe, high quality product.

  1. Windrow composting takes place in linear piles as organic material is blended, then turned at regular intervals to provide aeration. This is the simplest compost process, having the lowest level of process control and requiring very little inputs (e.g. electricity, etc.).
  2. In Aerated Static Pile (ASP) composting, piles of blended organic waste materials remain stationary throughout the process and are aerated by a circulation system. ASP composting offers more process controls than windrow composting, reducing stabilization time and land area required for a site. Process air pulled through the active composting piles can be directed to odor control equipment such as a biofilter.
  3. In-vessel composting processes use an automated, fully enclosed system that mechanically agitates and aerates blended organic materials in concrete bays. In-vessel composting features maximum process control and is generally preferred where site selection dictates maximum odor control and where weather conditions warrant an indoor composting process.
LA Sanitation produces a compost product at the Griffith Park Compost Facility.

 

LAND APPLICATION 

 Biosolids Land Application Image


Land Application is the addition of biosolids to land to condition the soil, fertilize crops or other vegetation grown in soil in order to supply nutrients and replenish soil organic matter.

Land application can occur on agricultural land, forests, rangelands, or on disturbed land in need of reclamation. Land application of biosolids has been practiced for thousands of years and has been studied and researched extensively. For more information on biosolids land application view the fact sheet.

LA Sanitation manages land application at several locations. An example of this is Green Acres Farm. To find out more about this specific site click here.

 
 

DEEP WELL INJECTION 

Deep Well injection picture


LA Sanitation and GeoMechanics Technology in collaboration with the US Environmental Protection Agency and with research support from the US Department of Energy and the National Science Foundation has embarked on an innovative technology to inject biosolids deep below the geological subsurface at its Terminal Island Water Reclamation Plant (TIWRP).

The Terminal Island Renewable Energy Project (TIRE) is the first of its kind in the nation and has been in operation for since July 2008. It is being demonstrated under a US EPA Underground Injection Control (UIC) permit.  TIRE places biosolids in depleted deep subsurface oil and gas formations where the earth’s high temperature would biodegrade the organic compounds to generate methane gas, which can ultimately be used to produce an environmentally safe renewable energy while the carbon dioxide is sequestered.  

Three wells have been drilled to a depth of approximately 5,300 feet beneath the TIWRP. So far, TIRE has successfully injected over 200 million gallons of bio-slurry material which includes brine, treated effluent, digested sludge and re-slurried biosolids.

Currently all 50 tons of biosolids produced at TIWRP is being managed at the TIRE facility and 150 tons from the Hyperion Water Reclamation. The injection well is accepting the material and formation response is good. The operations are continuously monitored daily and data is reported to the US EPA and a Technical Advisory Committee.  

Environmental documents, permits, and contracts were completed and approved for the TIRE project. Click here to view the permits and contracts associated with the project.

To ensure that the interested parties and public are engaged and informed about the TIRE project, LA Sanitation provides presentations, tours and project updates. The first presentation was held in 2001 where over 43 participants attended. To date over 165 presentations and more than 5,000 people updates have been provided.

Documents related to this project can be viewed here.


LANDFILL

LA Sanitation is committed to 100% beneficial resuse of its biosolids. Therefore LASAN does not manage its biosolids at a landfill.