Report to: GENERAL COMMITTEE Date of Meeting: May 15, 2006

Finance and Administration

SUBJECT: Implementation of Aerobic Landfill at Settler’s Park Landfill Site

PREPARED BY: Steve Andrews, Director of Asset Management, ext. 4703

Stan Lau, Senior Project Manager, ext. 3010

RECOMMENDATION:

THAT the report entitled “Implementation of Aerobic Landfill at Settler’s Park Landfill Site” be received;

AND THAT Beatty & Associates be retained to carry out the final design, preparation of tender document, site supervision and contract administration for the Installation of Aerobic Landfill and Leachate Recirculation System at the Settler’s Park Landfill site at an upset limit of $108,000 (excluding GST);

AND THAT the tendering process for retaining consultant services be waived in accordance with Purchasing By-Law 2004-341, Part II Section 7(h) “where it is necessary or in the best interests of the Town to acquire non-standard items or Consulting and Professional Services from a preferred supplier or from a supplier who has a proven track record with the Town in terms of pricing, quality and service”;

AND THAT the cost for the project be funded from the 2006 Capital Budget, Account No.058-5399-7028-005.

AND FURTHER THAT a Public Information meeting be held in July/August 2006 to advise the local residents of the undertaking.

FINANCIAL CONSIDERATIONS:

The following table is a summary of the financial considerations for this report:
Original Budget and Account #	$700,000	058-5399-7028-005
Current Budget Available (unspent)	$700,000
Less Cost	($108,000)	Awarded to Beatty and Associates
Less Contingency
Budget Remaining	$592,000
Close upon final payment:	NO
Future Financial Impact:	YES
Finance Department Comments:	NO

1. Purpose 2. Background 3. Discussion 4. Financial 5. Environmental

6. Accessibility 7. Engage ^21st 8. Affected Units 9. Attachment(s)

PURPOSE:

The purpose of this report is to obtain authorization to proceed with the installation of the Aerobic Landfill and Leachate Recirculation System at the Settler’s Park Landfill site and to retain a consultant to implement the project, including the preparation of contract drawings and documents, provision of contract supervision and administration services in 2006.

BACKGROUND:

Beatty & Associates was retained by the Town in November 2004 to carry out a leachate plume assessment in the vicinity of the Settler’s Park Landfill site and to carry out a detail design of an aerobic landfill system. A report entitled “Settler’s Park Landfill Site Management – Status Update” outlining the findings was submitted to Council on November 7, 2005.

System design of the aerobic landfill and leachate recirculation has been completed and is ready to proceed to the implementation stage.

A copy of the report entitled “Aerobic Landfill and Leachate Management System, Settler’s Park” is attached for reference. (Attachment ‘1’)

OPTIONS/ DISCUSSION:

The results of all the studies carried out at the Settler’s Park landfill site in the last few years are summarized below:

Landfill Gases:

Methane gas has been and is continuously being generated in the Settler’s Park landfill site. Positive pressure inside the landfill forces the methane gas either to escape through the landfill cap directly into the atmosphere or migrate laterally via unsaturated sandy deposits beneath some of the abutting residential homes.

Over the past 20 years, Markham has operated the gas recovery well system along the north and west sides of the site to protect the abutting residents. However, on-going and unpredicted damages of the header pipes due to uneven ground settlement, plugging of the gas recovery well screens and failure of header flow-control valves etc., require frequent reactive mitigation. Proactive mitigation has not been possible because of the lack of stable ground around the site perimeter. As well, the gas burning system installed in the fan house has not been working for the past few years due to the lack of gases that can be collected for burning.

Landfill Leachate:

The lack of a liner beneath the landfill results in leachate percolation downward into the ground water regime. The leachate plume is then transported east in the aquifer flow and seeps into the German Mills Creek.

Comparison of the upstream and downstream water samples indicates that the landfill leachate plume does not cause a significant impact to German Mills Creek. This is largely due to the fact that the flow in the stream is several hundred times greater than the groundwater flow beneath the landfill. The leachate impacts appear to be limited mainly to the small flow of groundwater which discharges through the bottom sediments and into the stream.

Long Term Care and Liability:

The organic waste in landfills typically takes over 100 years to fully decompose. As a result, landfill owners are required to commit funds for long term care and monitoring of the site.

It has been over 30 years since the Settler’s Park landfill closed, however, samples of raw waste collected during drilling operations indicate that the decomposition process is proceeding very slowly and the current methane and leachate impacts are expected to last for many more decades. In reality, the Town will be liable for environmental protection until the landfill decomposes to an acceptable level.

Aerobic Landfill Technology:

The result of the aerobic pilot test demonstrated that it is feasible to reduce methane to non-hazardous level by utilizing aerobic landfill technology.

When oxygen and moisture is injected into a landfill, the biodegradation process is transformed from anaerobic to aerobic. The result is a gradual decrease in methane production and the production of thermal energy. Once established, the aerobic process achieves much more rapid stabilization of the waste than anaerobic process. It is expected that the aerobic landfill will shorten the waste decomposition process by decades. This in turn, reduces the financial burden for maintenance of the site and converts the site from an environmental liability to a significant community asset in a much shorter time frame.

Implementation of aerobic landfill requires the installation of a network of air injection wells. Atmosphere air is injected and distributed to the injection wells through a system of flexible header pipes that are buried just below the ground surface.

Leachate Recirculation:

An effective way to contain the leachate and to add moisture to the aerobic landfill is by recirculation of the leachate that is discharging into the German Mills Creek. The most cost effective method of intercepting the leachate is by means of shallow wells installed along the west bank of German Mills Creek. These wells would be connected to a common header and a suction pump, the leachate will then be distributed across the surface of the landfill by shallow infiltration pipes.

The leachate recirculation system will only operate during the frost-free period. This eliminates the need for deep burial of the piping and operation of the system under freezing conditions which will result in cost savings.

Cost Estimate:

Total project cost for implementation of the aerobic landfill and the leachate recirculation system is estimated at $700,000. This includes an estimated engineering fee of $108,000 (excluding GST) for final design, preparation of contract drawings and tender documents, site supervision and contract administration.

Conclusion:

From the results of all the studies carried out in the Settler’s Park Landfill site in the past four years, it can be concluded that it is feasible to apply the aerobic landfill technology to this site. The most cost effective method to supplement the aerobic landfill and at the same time eliminate the risk of leachate from seeping into the German Mills Creek is to intercept and re-circulate the leachate into the aerobic landfill system. The technology provides an opportunity to convert an environmental liability into a community asset, while at the same time achieving a major reduction in greenhouse gas emissions.

Except for the small scale application in the City of Toronto’s Donlands landfill site using the aerobic landfill theory some 25 years ago, the proposed aerobic landfill and leachate recirculation system for Settler’s Park will be the first full scale application in Canada. This will provide Markham with a leadership role in demonstrating a more sustainable and cost effective landfill technology for the vast number of small and medium municipal landfills in Canada.

It is recommended that the Asset Management Department be authorized to proceed with the installation of an aerobic landfill and leachate recirculation system at the Settler’s Park Landfill site at an estimated total project cost of $700,000.

It is also recommended that Beatty & Associates be retained to carry out the final design, preparation of tender document, site supervision and contract administration for the Installation of Aerobic Landfill and Leachate Recirculation System at the Settler’s Park Landfill site at an upset limit of $108,000 (excluding GST).

As well, it is proposed to hold a Public Information meeting in July/August 2006 to advise the local residents of the proposed undertaking.

FINANCIAL TEMPLATE (Separate Attachment):

See attached

ENVIRONMENTAL CONSIDERATIONS:

There is interest at all government levels in promoting landfill methane emissions reduction as a viable way to meeting greenhouse gas reduction targets. The use of aerobic landfill technology may assist the Town in its commitment to meet the objectives of the Kyoto Protocol. It will also allow enhanced use of land in a passive or active manner by the public at a much shorter time frame.

With the implementation of the Aerobic Landfill Technology, the quantification of CO₂ and methane reduction is still under investigation and further assessment will be required to confirm if the reductions can be quantified and if the Town will be eligible for future greenhouse gas credits.

ACCESSIBILITY CONSIDERATIONS:

Not applicable

ENGAGE 21^ST CONSIDERATIONS:

Not applicable

BUSINESS UNITS CONSULTED AND AFFECTED:

Operations Department has been involved in the development of this project.

As well, Town staff have met with the Toronto and Region Conservation Authority (TRCA) and have shared the findings of the studies with them. The TRCA has expressed interest in the project and may be willing to participate in the water quality monitoring program.

RECOMMENDED

BY: ________________________ ________________________

Steve Andrews Jim Sales

Director of Asset Management Commissioner of Community and Fire Services

ATTACHMENTS:

Attachment ‘1’ - Aerobic Landfill and Leachate Management System, Settler’s Park

Q:\Commission Share\Operations and Asset Management\Reports\2006\Asset Management\Capital Works, ROW\Settlers Park Report\Implementation of Aerobic Landfill at Settler's Park Landfill Site(May 2).doc