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HomeMy WebLinkAboutDTS-06-133 - Bramm St Yards Project UpdateJ KTC R Developm ent & Technical Services Report To: Date of Meeting: Submitted By: Prepared By: Ward(s) Involved: Date of Report: Report No.: Subject: RECOMMENDATION: REPORT Development & Technical Services Committee September 5, 2006 James Witmer, Director of Building and Environmental Remediation James Witmer, Director of Building and Environmental Remediation Ward #6 August 25, 2006 DTS — 06 -133 BRAMM STREET YARDS PROJECT UPDATE "That Council approve an upset limit of $89,450 for additional work associated with the remediation of gasoline related contamination in the soil and groundwater at the Bramm Street Yards." EXECUTIVE SUMMARY: As Council is aware there seems to be a propensity toward an increase in cost when dealing with environmental related matters. The difficulty in providing cost estimates is that they are often based on an analysis of the data collected from a series of 2" diameter holes and interpolating the subsurface conditions between the boreholes. To date the estimates that we have received have been accurate when taking into consideration the scope of the work that they were intended to resolve. However, there is a need for more certainty when budgeting for these projects. Test pits are also an available tool, however, their use can be limited to the sites ability to function and be restored during the initial investigation. The historic information which consists of fire insurance maps, aerial photographs and the ability to locate and interview persons with historic knowledge leads to a certain degree of accuracy, but, in many instances it does not guarantee complete accuracy of the subsurface conditions. One would argue then that more test holes should be completed to obtain a better understanding of the subsurface conditions, and that is correct to a point. The difficulty is determining at which point do we stop spending money on testing and direct that money toward the remediation, knowing that at the end of the day the environmental issue still must be dealt with. BACKGROUND: On March 27, 2006 Council approved a Remedial Action Plan as outlined in Development and Technical Services report DTS -06 -048 for environmental remediation of the Bramm Street Yards and the adjacent parking lot at 72 Victoria St. S. This approval had an upset limit of $300,000 based on the available information at the time of Council's approval. It was stated that should additional costs be realized that Council would be notified prior to the additional funds being expended. A Phase II ESA had been carried out for the adjoining property located at 72 Victoria Street South that revealed an environmental issue which was suspected to have originated on the Bramm Street Operations Centre Property. Frontline Environmental was retained by the City to conduct a Supplemental Phase it ESA at the Bramm Street Yards to delineate the extent of petroleum hydrocarbon impacts in soil and groundwater extending from the Bramm Street property to the 72 Victoria Street South property and to develop remediation options. The results of the investigation had determined that the cause of the contamination was not known. Based on chemical analysis, monitoring well (MW9) appeared to be located within the source area on the Bramm Street Operations Centre, since the hydrocarbons were detected near ground surface and the highest concentrations measured at that location. It was likely that this was historical contamination associated with past land use of the property. Based on the laboratory testing data from the soil and groundwater in this area of concern, the hydrocarbon impacts are consistent with impacts from gasoline as the soil in this area was found to be grey stained and revealed a strong gasoline like odour. REPORT: The approved Option was estimated to be $300,000 and comprised excavation of impacted soil, bioremediation of soil and in -situ treatment of groundwater. The clean -up cost was based on a borehole program and testing at the Bramm Street Yard and 72 Victoria Street South property along with best available historic records showing use of the yard. During remediation planning it was estimated that 1900 tonnes of material would be managed and either hauled to the landfill for disposal and/or bioremediated at the Bramm Street Yard and used as backfill. The actual quantity of impacted soil was 3600 tonnes, of which 600 tonnes of soil was excavated and shipped to the Regional landfill and 3000 tonnes of soil excavated, remediated and hauled to Battler Yard. Based on the increased volumes of soil required to be managed as well as the need to address the high chloride levels in the ground water, the over -all budget for remediation may be required to be increased by $89,450 for these budgeted items. The over -run amounts are attributed to the following: 1. Expanded area of soil impact which included the discovery of a buried underground foundation and basement of a building with evidence of boiler ash, cinders and oil pipes. 2. Limited use of the Bramm Yard for soil stockpile which required significant volumes of clean stripped surface soil to be hauled to the Battler Yard and returned for backfill. 3. Larger expanded work area which required additional time for City forces to excavate, backfill and resurface. 4. Expanded restoration of asphalt. N 5. Off -site disposal of ash and cinder soils that were unrelated to the hydrocarbon impacts and not identified by the spacing of boreholes in the work area. 6. Larger expanded area of groundwater remediation at the Bramm Street Yard. 7. Higher than anticipated levels of chloride in soil and groundwater due to salt storage in the adjacent building at Bramm Street, which may increase the injections of bacteria into the soil and groundwater for hydrocarbon clean -up. The attached chart identifies where we are to date and what the anticipated final costs will be due to the increased soils to be managed and remediated. To date the funds expended for the budgeted portion of the project are $249,450. The cost for the City forces to complete the project is being allocated in order to apportion the real costs associated with this environmental clean -up. To date these costs are approximately $151,000. FINANCIAL IMPLICATIONS: This project will continue to be funded from the Brownfield Remediation capital account, which has an unexpended and unencumbered balance of $766,627.20 as of this date. Respectfully submitted, .James A. Witmer, Director of Building and Environmental Remediation List of Attachments Chart — Bramm Street Works Yard Budget 3