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1.0 EXECUTIVE SUMMARY

GeoTrans, Inc. was contracted by the City of Milwaukee to complete a site investigation of the Hartung Quarry Landfill. The landfill is located on a 16-acre parcel of land in Milwaukee County, Wisconsin. The western portion of the landfill is located in the City of Wauwatosa while the eastern portion is located in the City of Milwaukee.

The Hartung Quarry began use as a sanitary landfill on May 18^th, 1964. From 1964 to 1971 the lifts were composed primarily of noncombustible municipal waste and were documented as being trash and other wastes (furniture and appliances, street sweepings, leaves). From the early 1970's until the present the landfill has accepted only clean fill; concrete, asphalt, and soil.

The geology in the area is very generally described as unconsolidated glacial deposits overlying dolomite bedrock. The overburden is primarily composed of silt to silty-clay glacial till with alluvial deposits consisting of sand and gravel deposited near rivers in the area. Bedrock in the area consists of Niagara Dolomite made up of the Racine and Waukesha Formations underlain by the Maquoketa Shale and subsequently a series of Ordovician and Cambrian sandstone units.

Four monitoring wells, one piezometer, and four gas probes were constructed to evaluate the environmental impacts of the wastes deposited on site. [See Map]

According to surveys conducted of the landfill, historic photos and documentation, and the recent site investigation, the typical municipal wastes are at the bottom of the landfill and are limited in aerial extent to approximately 9 acres. The clean fill placed in the landfill tends to make up the majority of material placed in the former quarry. The site investigation revealed that the municipal waste tends to be highly degraded material consisting of glass, metal, and wood fragments. The deepest portion of the landfill is about 110 feet deep, as compared to the Menomonee River Parkway.

The site investigation shows that the shallow groundwater is flowing toward the on-site pond [See Map]. The water level in the pond is lower than the surrounding water levels in the monitoring wells and approximately 10 feet lower than the Menomonee River adjacent to the landfill. This flow occurs while the onsite pond is pumped. During the nonpumping period in the winter, the natural flow is expected as being toward the Menomonee River, to the west. The horizontal groundwater gradient ranges in value from 0.01 to 0.016. The hydraulic conductivity values range from 1.5 x 10^-3 cm/sec in MW-1 to 2.3 x 10^-5 in MW-4. The groundwater velocity ranges from 127 ft/year to 1.2 ft/year in the velocity calculations for MW-1 and MW-4 respectively. The average velocity calculated is 43 feet per year.

Groundwater samples were taken from each of the five wells. All Volatile Organic Compounds (VOCs) were below limits of quantification in all groundwater samples. All groundwater samples exceeded the Preventive Action Limit (PAL) for arsenic. Samples from MW-1 and P-1 exceeded the PAL for manganese, and MW-2, MW-3, and MW-4 exceeded the Enforcement Standard (ES) for manganese and chloride. Samples from P-1 and MW-2 exceeded the PAL for sulfate.

Methane gas at concentrations greater than its Lower Explosive Limit (LEL) was detected in the four gas probes located within the fill. No methane was detected in any of the monitor wells around the perimeter of the landfill.

The remaining capacity of the site is about 320,000 cubic yards, or about 6.5 years, based upon the final topography that was proposed in 1959. The final topography proposed in 1959 may not be appropriate for some recreational uses, and can be revised once the final end use of the site has been selected. Revising the final topography may reduce the lifespan of the site.

The following are recommended for the Hartung Quarry Landfill:

1. An engineered, low permeability cap is not necessary, nor is it recommended for the Hartung Quarry Landfill.

2. Enclosed structures are not recommended for the fill areas of the site because of methane gas generation. Open structures such as picnic pavilions, would be appropriate as long as the fill soils can provide adequate bearing capacity for such a structure. Because of depth, age and limited quantities of waste materials, and because a low permeability cap is not needed for the site, a gas extraction or venting system is not recommended for the site at this time.

3. Because of the difficulty in obtaining approval from the WDNR, it is not recommended that the existing on-site pond be retained after closure of the landfill.

4. Groundwater quality should be tested for four quarters, and then discontinued unless additional contaminants are detected. Groundwater monitoring should occur during at least one quarter when the pond is not being pumped.

5. Various stakeholders, including nearby residents, the Milwaukee County Park Commission, elected officials in the City of Milwaukee and the City of Wauwatosa, and Milwaukee Department of Public Works staff should provide input for final end uses of the Hartung Quarry Landfill. End uses could include a variety of recreational, and possibly flood control uses.

6. Once a consensus has been reached regarding the final end use of the site, the final topography of the site should be revised to accommodate future site needs.