GAS RECOVERY SYSTEMS

August 20, 1990

OJrI-lllli. rr:

PUBUC WORKS DEPT

Mr. John Mitchell City of Fresno 2326 Fresno Street Fresno, CA 93721

Re: City of Fresno Landfill Gas to Electrical Energy Project

SFUND RECORDS CTR 1751-00092

AR0023

Dear Mr. Mitchell:

As pranised last week during the meeting at the EPA, please find attached a project description of the project Laidlaw would like to develop at the Fresno landfill.

The general site plan indicates the extent of the l a n d f i l l gas collection systan with the main header located in the center of the system and connected to an electrical generation f a c i l i t y on the.east side of the land f i l l near Annadale Avenue. At this location, the fa c i l i t y is the furthest fron a l l existing housing and residential development. The condensate storage remains on the east side of the land f i l l adjacent to West Avenue. This location is consistent with disposal of the condensate to the sewer line near North Avenue.

The objective of this submittal is to obtain permission from the EPA for the gas collection systan in order that we can begin construction of the gas wells on November 1, 1990.

I have also included several photographs of a project very similar to the one proposed at Fresno. At this time we would anticipate an electrical generating facility housing intemal combustion engines capable of generating approximately 1500 kw of electricity.

I trust that the above information is suitable for submittal to your superfund consultant who will prepare i t in superfund format and language. I wi l l be happy to answer any questions or provide additional technical information.

Very truly yours,

George R. Jansen Vice President

SFUND RECORDS CTR

88111864

cc: J . Kehres K. Wuest

39899 BAL ENTINE DRIVE. SUITE 275, NEWARK, CALIFORNIA 94560 (415) 656-8327

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GAS RECOVERY SYSTEM

Citv of Fresno Landfill Gas Project

Proiect Objectives

The project is proposed for three purposes.

1. The control landfill gas migration and pollution. 2. As a resource recovery project generating electricity from a

resource that would otherwise be lost to the comnunity. 3. Project can provide a l l electrical needs of approximately 3,000

households.

Background

When natural organic matter deconposes, i t is transformed by the action of microorganism abundant in the refuse into a variety of sinpler organic materials. By-product gases are produced including carbon dioxide and methane, although oxygen, nitrogen, and hydrogen sulfide are also produced. The composition of the la n d f i l l gas undergoes a revolutionairy process as the refuse experiences f i r s t aerobic (oxygen-abundant), then anaerobic (oxygen-deficient) conditions.

Methane production from the Fresno Sanitary Landfill i s projected to occur over the next 20-year period. Preliminary testing of the project site indicates that methane is being produced in sufficient quantities to classify the landfill gas as a medium BTU fuel. Tests have shown that this medium BTU fuel when combined with the appropriate quantities of oxygen w i l l produce a combustible mixture which can be burned in place of natural gas in an intemal combustion engine.

Description of the Project

A schematic of the gas recovery planned for the Fresno Sanitary Landfill site is as shown in the attached drawing (Figure 1). Typically, the gas recovery system uses a system of induced exhaust wells consisting of perforated pipe casings placed in holes drilled in the refuse, backfilled with permeable material such as gravel, and sealed with impermeable material to prevent the inflow of air. The depth of the wells is dependent upon their proximity to the edge of the lan d f i l l and the depth of the refuse. Then, suction is applied to each well casing, to withdraw the gas and transport i t to the processing area by means of a pipe network shown in the "General Site Plan" drawing for the Fresno la n d f i l l . The processing plant contains a motor/blower unit or ccmpressor which allows the collection of gas and a process system to remove particulate matter, moisture, carbon dioxide, and any other contaminant from the gas. In this project, the processing plant is relatively simple and w i l l consist primarily of a small blower and filtration system to remove particulates and moisture. The gas is then fed to several internal combustion engines which are designed to bum the medium BTU fuel. These engines power generators which in turn generate electricity.

Projections based on an evaluation and analysis of the existing refuse, its depth and volume, indicate that enough gas should be available to initially operate enough intemal combustion engine generator sets to produce 1500 kilowatts (kw). Ultimately, the refuse continues to decompose and increase gas production, additional engine generators may be added. The electricity generated will be connected to PG&E grid in the area via a PG&E-designed electrical interconnect consisting of transformers and other related electrical equipment.

Aesthetic Impact

The gas recovery system wells will be placed underground. The pipe system connecting the wells to the processing facility initially will be above ground and will ultimately be buried when final cover is placed over the landfill. Each of the well heads will have connections for measuring instruments and valves for adjusting the gas pressures. The details of the collection system are shown on the drawing titled "Collection System Details."

The engine generator sets are modular, and skid mounted to allow for easy removal and installation; they are slightly taller than a large automobile and will occupy a space roughly equal to a large four-car garage. A building will be placed over the engine generator sets to provide protection from the rain. The building will also include a smELll room for all of the electrical controls and instruments. The gas processing plant is expected to be minimal and will be placed adjacent to the building housing the engine generator sets. The attached photographs of Laidlaw's Newby Island Site illustrate similar building and engine generator equipment that would be used at Fresno.

The PG&E interconnect will include a transformer and overhead wires which will connect the system to PG&E's grid alongside the proposed gas processing facility. This portion of the installation is expected to be outside of the engine generator set enclosure. The total system will be enclosed by a wire cyclone fence for security.

Project Operation

The gas field engine generator sets are expected to operate 24 hours per day with eight hours of site supervision. Safeguards will be built into the equifment for automatic shutdown and communication lines will be installed for remote 24-hour monitoring. The intemal combustion engines themselves will be muffled to minimize noise. These engines have been used for many years in all types of marine and industrial applications and meet all environmental noise criteria. It is not expected that the site will significantly contribute to the ambient noise levels already present in the area.

The project is expected to go on line approximately 120 to 180 days following receipt of all permits and approvals.

The project life is totally dependent on the amount and quality of the landfill gas generated within the landfill. Current projections indicate a useful life from between fifteen to twenty years.

Buildino Materials

The building itself is a modular "Butler type" building made of a steel frame and metal panels. The outside walls are painted; sliding doors and normal access doors are provided. The building itself will be built on a mat foundation approximately 12 inches thick.

Excavation/Grading

Other than minor site leveling, no major excavation is anticipated at the site.

EXAMPLE OF LANDFILL GAS TO ELECTRICAL ENERGY FACILITY

BUILDING - SHOWING INTERCONNECT

INTERNAL COMBUSTION ENGINES/GENERATORS

EXAMPLE OF LANDFILL GAS TO ELECTRICAL ENERGY FACILITY

GAS PROCESSING EQUIPMENT

BUILDING - SHOWING ENGINE COOLING EQUIPMENT

EXAMPLE OF LANDFILL GAS TO ELECTRICAL ENERGY FACILITY

BUILDING - SHOWING INTERCONNECT

INTERNAL COMBUSTION ENGINES/GENERATORS

EXAMPLE OF LANDFILL GAS TO ELECTRICAL ENERGY FACILITY

GAS PROCESSING EQUIPMENT

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BUILDING - SHOWING ENGINE COOLING EQUIPMENT

EXAMPLE OF LANDFILL GAS TO ELECTRICAL ENERGY FACILITY

BUILDING - SHOWING INTERCONNECT

INTERNAL COIBUSTION ENGINES/GENERATOIS

EXAMPLE OF LANDFILL GAS TO ELECTRICAL ENERGY FACILITY

GAS PROCESSING EQUIPMENT

BUILDING - SHOWING ENGINE COOLING EQUIPMENT

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