COMMITMENTS AND CONTINGENCIES	9 Months Ended
Sep. 30, 2012
Commitments and Contingencies Disclosure [Abstract]
COMMITMENTS AND CONTINGENCIES	COMMITMENTS AND CONTINGENCIES Legal and Administrative Proceedings The Company’s waste management services are regulated by federal, state, provincial and local laws enacted to regulate discharge of materials into the environment, remediation of contaminated soil and groundwater or otherwise protect the environment. This ongoing regulation results in the Company frequently becoming a party to legal or administrative proceedings involving all levels of governmental authorities and other interested parties. The issues involved in such proceedings generally relate to applications for permits and licenses by the Company and conformity with legal requirements, alleged violations of existing permits and licenses, or alleged responsibility arising under federal or state Superfund laws to remediate contamination at properties owned either by the Company or by other parties (“third party sites”) to which either the Company or prior owners of certain of the Company’s facilities shipped wastes. At September 30, 2012 and December 31, 2011, the Company had recorded reserves of $30.2 million and $30.3 million, respectively, in the Company’s financial statements for actual or probable liabilities related to the legal and administrative proceedings in which the Company was then involved, the principal of which are described below. At September 30, 2012 and December 31, 2011, the Company also believed that it was reasonably possible that the amount of these potential liabilities could be as much as $2.7 million more. The Company periodically adjusts the aggregate amount of these reserves when these actual or probable liabilities are paid or otherwise discharged, new claims arise, or additional relevant information about existing or probable claims becomes available. As of September 30, 2012, the $30.2 million of reserves consisted of (i) $27.4 million related to pending legal or administrative proceedings, including Superfund liabilities, which were included in remedial liabilities on the consolidated balance sheets and (ii) $2.8 million primarily related to federal and state enforcement actions, which were included in accrued expenses on the consolidated balance sheets. As of September 30, 2012, the principal legal and administrative proceedings in which the Company was involved were as follows: Ville Mercier. In September 2002, the Company acquired the stock of a subsidiary (the “Mercier Subsidiary”) which owns a hazardous waste incinerator in Ville Mercier, Quebec (the “Mercier Facility”). The property adjacent to the Mercier Facility, which is also owned by the Mercier Subsidiary, is now contaminated as a result of actions dating back to 1968, when the Government of Quebec issued to a company unrelated to the Mercier Subsidiary two permits to dump organic liquids into lagoons on the property. In 1999, Ville Mercier and three neighboring municipalities filed separate legal proceedings against the Mercier Subsidiary and the Government of Quebec claiming a total of $1.6 million as damages for additional costs to obtain drinking water supplies and seek an injunctive order to obligate the defendants to remediate the groundwater in the region. The Quebec Government also sued the Mercier Subsidiary to recover approximately $17.4 million (CDN) of alleged past costs for constructing and operating a treatment system and providing alternative drinking water supplies. On September 26, 2007, the Quebec Minister of Sustainable Development, Environment and Parks issued a Notice pursuant to Section 115.1 of the Environment Quality Act, superseding Notices issued in 1992, which are the subject of the pending litigation. The Mercier Subsidiary continues to assert that it has no responsibility for the groundwater contamination in the region and will contest any action by the Ministry to impose costs for remedial measures on the Mercier Subsidiary. The Company also continues to pursue settlement options. At September 30, 2012 and December 31, 2011, the Company had accrued $14.2 million and $13.3 million, respectively, for remedial liabilities relating to the Ville Mercier legal proceedings. Deer Trail, Colorado Facility. Since April 5, 2006, the Company has been involved in various legal proceedings which have arisen as a result of the issuance by the Colorado Department of Public Health and Environment (“CDPHE”) of a radioactive materials license (“RAD License”) to a Company subsidiary, Clean Harbors Deer Trail, LLC (“CHDT”) to accept certain low level radioactive materials known as “NORM/TENORM” wastes for disposal. Adams County, the county where the CHDT facility is located, filed two suits against the CDPHE in Colorado effectively seeking to invalidate the license. On December 16, 2011, the parties to the lawsuits described above reached an Agreement in Principle (“AIP”) to resolve all outstanding disputes. The AIP required additional approvals by County and State authorities before a final settlement and dismissal of the lawsuits can be finalized, and the approvals were obtained in November 2012. Superfund Proceedings The Company has been notified that either the Company or the prior owners of certain of the Company’s facilities for which the Company may have certain indemnification obligations have been identified as potentially responsible parties (“PRPs”) or potential PRPs in connection with 68 sites which are subject to or are proposed to become subject to proceedings under federal or state Superfund laws. Of the 68 sites, two involve facilities that are now owned by the Company and 66 involve third party sites to which either the Company or the prior owners shipped wastes. In connection with each site, the Company has estimated the extent, if any, to which it may be subject, either directly or as a result of any such indemnification provisions, for cleanup and remediation costs, related legal and consulting costs associated with PRP investigations, settlements, and related legal and administrative proceedings. The amount of such actual and potential liability is inherently difficult to estimate because of, among other relevant factors, uncertainties as to the legal liability (if any) of the Company or the prior owners of certain of the Company’s facilities to contribute a portion of the cleanup costs, the assumptions that must be made in calculating the estimated cost and timing of remediation, the identification of other PRPs and their respective capability and obligation to contribute to remediation efforts, and the existence and legal standing of indemnification agreements (if any) with prior owners, which may either benefit the Company or subject the Company to potential indemnification obligations. The Company’s potential liability for cleanup costs at the two facilities now owned by the Company and at 35 (the “Listed Third Party Sites”) of the 66 third party sites arose out of the Company’s 2002 acquisition of substantially all of the assets (the “CSD assets”) of the Chemical Services Division of Safety-Kleen Corp. As part of the purchase price for the CSD assets, the Company became liable as the owner of these two facilities and also agreed to indemnify the prior owners of the CSD assets against their share of certain cleanup costs for the Listed Third Party Sites payable to governmental entities under federal or state Superfund laws. Of the 35 Listed Third Party Sites, seven are currently requiring expenditures on remediation, 13 are now settled, and 15 are not currently requiring expenditures on remediation. The status of one of the facilities now owned by the Company (the BR Facility) and one of the Listed Third Party Sites (the Casmalia site) are further described below. There are also two third party sites at which the Company has been named a PRP as a result of its acquisition of the CSD assets but disputes that it has any cleanup or related liabilities; one such site (the Marine Shale site) is described below. The Company views any liabilities associated with the Marine Shale site and the other third party site as excluded liabilities under the terms of the CSD asset acquisition, but the Company is working with the EPA on a potential settlement. In addition to the CSD related Superfund sites, there are certain of the other third party sites which are not related to the Company’s acquisition of the CSD assets, and certain notifications which the Company has received about other third party sites. BR Facility. The Company acquired in 2002 as part of the CSD assets a former hazardous waste incinerator and landfill in Baton Rouge (the “BR Facility”), for which operations had been previously discontinued by the prior owner. In September 2007, the United States Environmental Protection Agency (the “EPA”) issued a special notice letter to the Company related to the Devil’s Swamp Lake Site (“Devil’s Swamp”) in East Baton Rouge Parish, Louisiana. Devil’s Swamp includes a lake located downstream of an outfall ditch where wastewater and stormwater have been discharged, and Devil’s Swamp is proposed to be included on the National Priorities List due to the presence of Contaminants of Concern (“COC”) cited by the EPA. These COCs include substances of the kind found in wastewater and storm water discharged from the BR Facility in past operations. The EPA originally requested COC generators to submit a good faith offer to conduct a remedial investigation feasibility study directed towards the eventual remediation of the site. The Company is currently performing corrective actions at the BR Facility under an order issued by the Louisiana Department of Environmental Quality (the “LDEQ”), and has begun conducting the remedial investigation and feasibility study under an order issued by the EPA. The Company cannot presently estimate the potential additional liability for the Devil’s Swamp cleanup until a final remedy is selected by the EPA. Casmalia Site. At one of the 35 Listed Third Party Sites, the Casmalia Resources Hazardous Waste Management Facility (the “Casmalia site”) in Santa Barbara County, California, the Company received from the EPA a request for information in May 2007. In that request, the EPA is seeking information about the extent to which, if at all, the prior owner transported or arranged for disposal of waste at the Casmalia site. The Company has not recorded any liability for this 2007 notice on the basis that such transporter or arranger liability is currently neither probable nor estimable. Marine Shale Site. On May 11, 2007, the EPA and the LDEQ issued a special notice to the Company and other PRPs, seeking a good faith offer to address site remediation at the former Marine Shale facility. Certain of the former owners of the CSD assets were major customers of Marine Shale, but the Marine Shale site was not included as a Listed Third Party Site in connection with the Company’s acquisition of the CSD assets and the Company was never a customer of Marine Shale. Although the Company believes that it is not liable (either directly or under any indemnification obligation) for cleanup costs at the Marine Shale site, the Company elected to join with other parties which had been notified that are potentially PRPs in connection with Marine Shale site to form a group (the “Site Group”) to retain common counsel and participate in further negotiations with the EPA and the LDEQ directed towards the eventual remediation of the Marine Shale site. The Site Group made a good faith settlement offer to the EPA on November 29, 2007, and negotiations among the EPA, the LDEQ and the Site Group with respect to the Marine Shale site are ongoing. At September 30, 2012 and December 31, 2011, the amount of the Company’s reserves relating to the Marine Shale site was $4 million and $3.8 million, respectively. Certain Other Third Party Sites. At 15 of the 66 third party sites, the Company has an indemnification agreement with ChemWaste, a former subsidiary of Waste Management, Inc. and the prior owner. The agreement indemnifies the Company with respect to any liability at the 15 sites for waste disposed prior to the Company’s acquisition of the sites. Accordingly, Waste Management is paying all costs of defending those subsidiaries in those 15 cases, including legal fees and settlement costs. However, there can be no guarantee that the Company’s ultimate liabilities for these sites will not exceed the amount recorded or that indemnities applicable to any of these sites will be available to pay all or a portion of related costs. The Company does not have an indemnity agreement with respect to any of the other remaining 66 third party sites not discussed above. However, the Company believes that its additional potential liability, if any, to contribute to the cleanup of such remaining sites will not, in the aggregate, exceed $100,000. Other Notifications. Between September 2004 and May 2006, the Company also received notices from certain of the prior owners of the CSD assets seeking indemnification from the Company at five third party sites which are not included in the third party sites described above that have been designated as Superfund sites or potential Superfund sites and for which those prior owners have been identified as PRPs or potential PRPs. The Company has responded to such letters asserting that the Company has no obligation to indemnify those prior owners for any cleanup and related costs (if any) which they may incur in connection with these five sites. The Company intends to assist those prior owners by providing information that is now in the Company’s possession with respect to those five sites and, if appropriate, to participate in negotiations with the government agencies and PRP groups involved. The Company has also investigated the sites to determine the existence of potential liabilities independent from the liability of those former owners, and concluded that at this time the Company is not liable for any portion of the potential cleanup of the five sites and therefore has not established a reserve. Federal, State and Provincial Enforcement Actions From time to time, the Company pays fines or penalties in regulatory proceedings relating primarily to waste treatment, storage or disposal facilities. As of September 30, 2012 and December 31, 2011, there were three and four proceedings, respectively, for which the Company reasonably believed that the sanctions could equal or exceed $100,000. The Company believes that the fines or other penalties in these or any of the other regulatory proceedings, individually or in the aggregate, will not have a material adverse effect on its financial condition, results of operations or cash flows. Other Contingencies In December 2010, the Company paid $10.5 million to acquire a minority interest in Safety-Kleen, Inc. ("Safety-Kleen"). Subsequent to the purchase of those securities but prior to December 31, 2010, Safety-Kleen exercised its irrevocable call right for those shares and tendered payment for a total of $10.5 million. The Company is disputing the fair value attributable to the minority interest by the privately-held company and has recorded the $10.5 million in prepaid expenses and other current assets. The potential recovery of any additional amount depends upon several contested factors, and is considered a gain contingency and therefore has not been recorded in the Company’s consolidated financial statements. Subsequent to September 30, 2012, the Company has stayed the litigation pending the completion of the Company's proposed acquisition of Safety-Kleen.

COMMITMENTS AND CONTINGENCIES

Legal and Administrative Proceedings

The Company’s waste management services are regulated by federal, state, provincial and local laws enacted to regulate discharge of materials into the environment, remediation of contaminated soil and groundwater or otherwise protect the environment. This ongoing regulation results in the Company frequently becoming a party to legal or administrative proceedings involving all levels of governmental authorities and other interested parties. The issues involved in such proceedings generally relate to applications for permits and licenses by the Company and conformity with legal requirements, alleged violations of existing permits and licenses, or alleged responsibility arising under federal or state Superfund laws to remediate contamination at properties owned either by the Company or by other parties (“third party sites”) to which either the Company or prior owners of certain of the Company’s facilities shipped wastes.

At September 30, 2012 and December 31, 2011, the Company had recorded reserves of $30.2 million and $30.3 million, respectively, in the Company’s financial statements for actual or probable liabilities related to the legal and administrative proceedings in which the Company was then involved, the principal of which are described below. At September 30, 2012 and December 31, 2011, the Company also believed that it was reasonably possible that the amount of these potential liabilities could be as much as $2.7 million more. The Company periodically adjusts the aggregate amount of these reserves when these actual or probable liabilities are paid or otherwise discharged, new claims arise, or additional relevant information about existing or probable claims becomes available. As of September 30, 2012, the $30.2 million of reserves consisted of (i) $27.4 million related to pending legal or administrative proceedings, including Superfund liabilities, which were included in remedial liabilities on the consolidated balance sheets and (ii) $2.8 million primarily related to federal and state enforcement actions, which were included in accrued expenses on the consolidated balance sheets.

As of September 30, 2012, the principal legal and administrative proceedings in which the Company was involved were as follows:

Ville Mercier. In September 2002, the Company acquired the stock of a subsidiary (the “Mercier Subsidiary”) which owns a hazardous waste incinerator in Ville Mercier, Quebec (the “Mercier Facility”). The property adjacent to the Mercier Facility, which is also owned by the Mercier Subsidiary, is now contaminated as a result of actions dating back to 1968, when the Government of Quebec issued to a company unrelated to the Mercier Subsidiary two permits to dump organic liquids into lagoons on the property. In 1999, Ville Mercier and three neighboring municipalities filed separate legal proceedings against the Mercier Subsidiary and the Government of Quebec claiming a total of $1.6 million as damages for additional costs to obtain drinking water supplies and seek an injunctive order to obligate the defendants to remediate the groundwater in the region. The Quebec Government also sued the Mercier Subsidiary to recover approximately $17.4 million (CDN) of alleged past costs for constructing and operating a treatment system and providing alternative drinking water supplies. On September 26, 2007, the Quebec Minister of Sustainable Development, Environment and Parks issued a Notice pursuant to Section 115.1 of the Environment Quality Act, superseding Notices issued in 1992, which are the subject of the pending litigation. The Mercier Subsidiary continues to assert that it has no responsibility for the groundwater contamination in the region and will contest any action by the Ministry to impose costs for remedial measures on the Mercier Subsidiary. The Company also continues to pursue settlement options. At September 30, 2012 and December 31, 2011, the Company had accrued $14.2 million and $13.3 million, respectively, for remedial liabilities relating to the Ville Mercier legal proceedings.

Deer Trail, Colorado Facility. Since April 5, 2006, the Company has been involved in various legal proceedings which have arisen as a result of the issuance by the Colorado Department of Public Health and Environment (“CDPHE”) of a radioactive materials license (“RAD License”) to a Company subsidiary, Clean Harbors Deer Trail, LLC (“CHDT”) to accept certain low level radioactive materials known as “NORM/TENORM” wastes for disposal. Adams County, the county where the CHDT facility is located, filed two suits against the CDPHE in Colorado effectively seeking to invalidate the license. On December 16, 2011, the parties to the lawsuits described above reached an Agreement in Principle (“AIP”) to resolve all outstanding disputes. The AIP required additional approvals by County and State authorities before a final settlement and dismissal of the lawsuits can be finalized, and the approvals were obtained in November 2012.

Superfund Proceedings

The Company has been notified that either the Company or the prior owners of certain of the Company’s facilities for which the Company may have certain indemnification obligations have been identified as potentially responsible parties (“PRPs”) or potential PRPs in connection with 68 sites which are subject to or are proposed to become subject to proceedings under federal or state Superfund laws. Of the 68 sites, two involve facilities that are now owned by the Company and 66 involve third party sites to which either the Company or the prior owners shipped wastes. In connection with each site, the Company has estimated the extent, if any, to which it may be subject, either directly or as a result of any such indemnification provisions, for cleanup and remediation costs, related legal and consulting costs associated with PRP investigations, settlements, and related legal and administrative proceedings. The amount of such actual and potential liability is inherently difficult to estimate because of, among other relevant factors, uncertainties as to the legal liability (if any) of the Company or the prior owners of certain of the Company’s facilities to contribute a portion of the cleanup costs, the assumptions that must be made in calculating the estimated cost and timing of remediation, the identification of other PRPs and their respective capability and obligation to contribute to remediation efforts, and the existence and legal standing of indemnification agreements (if any) with prior owners, which may either benefit the Company or subject the Company to potential indemnification obligations.

The Company’s potential liability for cleanup costs at the two facilities now owned by the Company and at 35 (the “Listed Third Party Sites”) of the 66 third party sites arose out of the Company’s 2002 acquisition of substantially all of the assets (the “CSD assets”) of the Chemical Services Division of Safety-Kleen Corp. As part of the purchase price for the CSD assets, the Company became liable as the owner of these two facilities and also agreed to indemnify the prior owners of the CSD assets against their share of certain cleanup costs for the Listed Third Party Sites payable to governmental entities under federal or state Superfund laws. Of the 35 Listed Third Party Sites, seven are currently requiring expenditures on remediation, 13 are now settled, and 15 are not currently requiring expenditures on remediation. The status of one of the facilities now owned by the Company (the BR Facility) and one of the Listed Third Party Sites (the Casmalia site) are further described below. There are also two third party sites at which the Company has been named a PRP as a result of its acquisition of the CSD assets but disputes that it has any cleanup or related liabilities; one such site (the Marine Shale site) is described below. The Company views any liabilities associated with the Marine Shale site and the other third party site as excluded liabilities under the terms of the CSD asset acquisition, but the Company is working with the EPA on a potential settlement. In addition to the CSD related Superfund sites, there are certain of the other third party sites which are not related to the Company’s acquisition of the CSD assets, and certain notifications which the Company has received about other third party sites.

BR Facility. The Company acquired in 2002 as part of the CSD assets a former hazardous waste incinerator and landfill in Baton Rouge (the “BR Facility”), for which operations had been previously discontinued by the prior owner. In September 2007, the United States Environmental Protection Agency (the “EPA”) issued a special notice letter to the Company related to the Devil’s Swamp Lake Site (“Devil’s Swamp”) in East Baton Rouge Parish, Louisiana. Devil’s Swamp includes a lake located downstream of an outfall ditch where wastewater and stormwater have been discharged, and Devil’s Swamp is proposed to be included on the National Priorities List due to the presence of Contaminants of Concern (“COC”) cited by the EPA. These COCs include substances of the kind found in wastewater and storm water discharged from the BR Facility in past operations. The EPA originally requested COC generators to submit a good faith offer to conduct a remedial investigation feasibility study directed towards the eventual remediation of the site. The Company is currently performing corrective actions at the BR Facility under an order issued by the Louisiana Department of Environmental Quality (the “LDEQ”), and has begun conducting the remedial investigation and feasibility study under an order issued by the EPA. The Company cannot presently estimate the potential additional liability for the Devil’s Swamp cleanup until a final remedy is selected by the EPA.

Casmalia Site. At one of the 35 Listed Third Party Sites, the Casmalia Resources Hazardous Waste Management Facility (the “Casmalia site”) in Santa Barbara County, California, the Company received from the EPA a request for information in May 2007. In that request, the EPA is seeking information about the extent to which, if at all, the prior owner transported or arranged for disposal of waste at the Casmalia site. The Company has not recorded any liability for this 2007 notice on the basis that such transporter or arranger liability is currently neither probable nor estimable.

Marine Shale Site. On May 11, 2007, the EPA and the LDEQ issued a special notice to the Company and other PRPs, seeking a good faith offer to address site remediation at the former Marine Shale facility. Certain of the former owners of the CSD assets were major customers of Marine Shale, but the Marine Shale site was not included as a Listed Third Party Site in connection with the Company’s acquisition of the CSD assets and the Company was never a customer of Marine Shale. Although the Company believes that it is not liable (either directly or under any indemnification obligation) for cleanup costs at the Marine Shale site, the Company elected to join with other parties which had been notified that are potentially PRPs in connection with Marine Shale site to form a group (the “Site Group”) to retain common counsel and participate in further negotiations with the EPA and the LDEQ directed towards the eventual remediation of the Marine Shale site. The Site Group made a good faith settlement offer to the EPA on November 29, 2007, and negotiations among the EPA, the LDEQ and the Site Group with respect to the Marine Shale site are ongoing. At September 30, 2012 and December 31, 2011, the amount of the Company’s reserves relating to the Marine Shale site was $4 million and $3.8 million, respectively.

Certain Other Third Party Sites. At 15 of the 66 third party sites, the Company has an indemnification agreement with ChemWaste, a former subsidiary of Waste Management, Inc. and the prior owner. The agreement indemnifies the Company with respect to any liability at the 15 sites for waste disposed prior to the Company’s acquisition of the sites. Accordingly, Waste Management is paying all costs of defending those subsidiaries in those 15 cases, including legal fees and settlement costs. However, there can be no guarantee that the Company’s ultimate liabilities for these sites will not exceed the amount recorded or that indemnities applicable to any of these sites will be available to pay all or a portion of related costs. The Company does not have an indemnity agreement with respect to any of the other remaining 66 third party sites not discussed above. However, the Company believes that its additional potential liability, if any, to contribute to the cleanup of such remaining sites will not, in the aggregate, exceed $100,000.

Other Notifications. Between September 2004 and May 2006, the Company also received notices from certain of the prior owners of the CSD assets seeking indemnification from the Company at five third party sites which are not included in the third party sites described above that have been designated as Superfund sites or potential Superfund sites and for which those prior owners have been identified as PRPs or potential PRPs. The Company has responded to such letters asserting that the Company has no obligation to indemnify those prior owners for any cleanup and related costs (if any) which they may incur in connection with these five sites. The Company intends to assist those prior owners by providing information that is now in the Company’s possession with respect to those five sites and, if appropriate, to participate in negotiations with the government agencies and PRP groups involved. The Company has also investigated the sites to determine the existence of potential liabilities independent from the liability of those former owners, and concluded that at this time the Company is not liable for any portion of the potential cleanup of the five sites and therefore has not established a reserve.

Federal, State and Provincial Enforcement Actions

From time to time, the Company pays fines or penalties in regulatory proceedings relating primarily to waste treatment, storage or disposal facilities. As of September 30, 2012 and December 31, 2011, there were three and four proceedings, respectively, for which the Company reasonably believed that the sanctions could equal or exceed $100,000. The Company believes that the fines or other penalties in these or any of the other regulatory proceedings, individually or in the aggregate, will not have a material adverse effect on its financial condition, results of operations or cash flows.

Other Contingencies

In December 2010, the Company paid $10.5 million to acquire a minority interest in Safety-Kleen, Inc. ("Safety-Kleen"). Subsequent to the purchase of those securities but prior to December 31, 2010, Safety-Kleen exercised its irrevocable call right for those shares and tendered payment for a total of $10.5 million. The Company is disputing the fair value attributable to the minority interest by the privately-held company and has recorded the $10.5 million in prepaid expenses and other current assets. The potential recovery of any additional amount depends upon several contested factors, and is considered a gain contingency and therefore has not been recorded in the Company’s consolidated financial statements. Subsequent to September 30, 2012, the Company has stayed the litigation pending the completion of the Company's proposed acquisition of Safety-Kleen.