COMMITMENTS AND CONTINGENCIES	9 Months Ended
Sep. 30, 2013
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, 2013 and December 31, 2012, the Company had recorded reserves of $41.8 million and $38.6 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, 2013 and December 31, 2012, the Company also believed that it was reasonably possible that the amount of these potential liabilities could be as much as $3.4 million and $3.5 million more, respectively. 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, 2013, the $41.8 million of reserves consisted of (i) $35.1 million related to pending legal or administrative proceedings, including Superfund liabilities, which were included in remedial liabilities on the consolidated balance sheets and (ii) $6.7 million primarily related to federal and state enforcement actions, which were included in accrued expenses on the consolidated balance sheets. As of September 30, 2013, the principal legal and administrative proceedings in which the Company was involved, or which had been terminated during 2013, 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. By 1972, groundwater contamination had been identified, and the Quebec government provided an alternate water supply to the municipality of Ville Mercier. In 1999, Ville Mercier and three neighboring municipalities filed separate legal proceedings against the Mercier Subsidiary and the Government of Quebec. The lawsuits assert that the defendants are jointly and severally responsible for the contamination of groundwater in the region, which they claim caused each municipality to incur additional costs to supply drinking water for their citizens since the 1970's and early 1980's. The four municipalities claim a Canadian dollar ("CDN") 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 more recent Notice notifies the Mercier Subsidiary that, if the Mercier Subsidiary does not take certain remedial measures at the site, the Minister intends to undertake those measures at the site and claim direct and indirect costs related to such measures. 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, 2013 and December 31, 2012, the Company had accrued $13.9 million and $14.2 million, respectively, for remedial liabilities relating to the Ville Mercier legal proceedings. Safety-Kleen Legal Proceedings. On December 28, 2012, the Company acquired Safety-Kleen and thereby became subject to the legal proceedings in which Safety-Kleen was a party on that date. In addition to certain Superfund proceedings in which Safety-Keen has been named as a potentially responsible party as described below under “Superfund Proceedings,” the principal such legal proceedings involving Safety-Kleen which were outstanding as of September 30, 2013 were as follows: Product Liability Cases - Safety-Kleen is named as a defendant in various lawsuits that are currently pending in various courts and jurisdictions throughout the United States, including approximately 62 proceedings (excluding cases which have been settled but not formally dismissed) as of September 30, 2013, wherein persons claim personal injury resulting from the use of Safety-Kleen's parts cleaning equipment or cleaning products. These proceedings typically involve allegations that the solvent used in Safety-Kleen's parts cleaning equipment contains contaminants and/or that Safety-Kleen's recycling process does not effectively remove the contaminants that become entrained in the solvent during their use. In addition, certain claimants assert that Safety-Kleen failed to warn adequately the product user of potential risks, including an historic failure to warn that solvent contains trace amounts of toxic or hazardous substances such as benzene. Safety-Kleen maintains insurance that it believes will provide coverage for these claims (over amounts accrued for self-insured retentions and deductibles in certain limited cases), except for punitive damages to the extent not insurable under state law or excluded from insurance coverage. Safety-Kleen believes that these claims lack merit and has historically vigorously defended, and intends to continue to vigorously defend, itself and the safety of its products against all of these claims. Such matters are subject to many uncertainties and outcomes are not predictable with assurance. Consequently, Safety-Kleen is unable to ascertain the ultimate aggregate amount of monetary liability or financial impact with respect to these matters as of September 30, 2013. From December 31, 2012 to September 30, 2013, 26 product liability claims were settled or dismissed. Due to the nature of these claims and the related insurance, Safety-Kleen did not incur any expense as Safety-Kleen's insurance provided coverage in full for all such claims. Safety-Kleen may be named in similar, additional lawsuits in the future, including claims for which insurance coverage may not be available. Fee Class Action Claims. In October 2010, two customers filed a complaint, individually and on behalf of all similarly situated customers in the State of Alabama, alleging that Safety-Kleen improperly assessed fuel surcharges and extended area service fees. Safety-Kleen disputes the basis of the claims on numerous grounds, including that Safety-Kleen has contracts with numerous customers authorizing the assessment of such fees and that in cases where no contract exists Safety-Kleen provides customers with a document at the time of service reflecting the assessment of the fee, followed by an invoice itemizing the fee. It is Safety-Kleen's position that it had the right to assess fuel surcharges, that the customers consented to the charges and that the surcharges were voluntarily paid by the customers when presented with an invoice. The lawsuit is still in its initial stages of discovery, with the focus being whether a class will be certified. The class certification-related fact discovery cutoff was September 4, 2013, and a hearing on class certification is now scheduled to be held in early to mid-2014. The plaintiff has filed a motion to extend the discovery cutoff and trial date, but the court has not ruled on these requests. In late June 2012, a nearly identical lawsuit was filed by the same law firm on behalf of a California-based customer. That lawsuit contends, under various state law theories, that Safety-Kleen impermissibly assessed fuel surcharges and late payment fees, and seeks certification of a class of California customers only. Safety-Kleen will assert the same defenses as in the Alabama litigation. In December 2012, a similar suit was filed by the same law firm on behalf of a Missouri-based customer which contends under various state law theories that Safety-Kleen impermissibly assessed fuel surcharges and seeks certification of a class of Missouri customers only. Safety-Kleen will assert the same defenses as in the Alabama and California cases. The Company is unable to ascertain the ultimate aggregate amount of monetary liability or financial impact with respect to these matters as of September 30, 2013, and no reserve has been recorded. Superfund Proceedings The Company has been notified that either the Company (which, since December 28, 2012, includes Safety-Kleen) 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 122 sites which are subject to or are proposed to become subject to proceedings under federal or state Superfund laws. Of the 122 sites, two involve facilities that are now owned by the Company and 120 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 120 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, six are currently requiring expenditures on remediation, 13 are now settled, and 16 are not currently requiring expenditures on remediation. The status of the two facilities owned by the Company (the Wichita Property and the BR Facility) are further described below. The 120 Superfund sites described above include 69 sites for which the Company had been notified it is a PRP or potential PRP prior to the Company's acquisition of Safety-Kleen on December 28, 2012, and an additional 50 sites at which Safety-Kleen had been notified it is a PRP or potential PRP prior to such acquisition. The total number of Superfund sites at which the Company had at September 30, 2013 potential liability and the total dollar amount of such estimated liability relating to those sites as described above have been increased to reflect the additional potential Superfund liabilities to which the Company became subject as a result of the Safety-Kleen acquisition. One of the third party sites (the Marine Shale site) is further described below. Wichita Property. The Company acquired in 2002 as part of the CSD assets a service center located in Wichita, Kansas (the "Wichita Property"). The Wichita Property is one of several properties located within the boundaries of a 1,400 acre state-designated Superfund site in an old industrial section of Wichita known as the North Industrial Corridor Site. Along with numerous other PRPs, the former owner executed a consent decree relating to such site with the U.S. Environmental Protection Agency (the "EPA"), and the Company is continuing its ongoing remediation program for the Wichita Property in accordance with that consent decree. The Company also acquired rights under an indemnification agreement between the former owner and an earlier owner of the Wichita Property, which the Company anticipates but cannot guarantee will be available to reimburse certain such cleanup costs. 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 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. Marine Shale Site. Prior to 1996, Marine Shale Processors, Inc. ("Marine Shale") operated a kiln in Amelia, Louisiana which incinerated waste producing a vitrified aggregate as a by-product. Marine Shale contended that its operation recycled waste into a useful product, i.e., vitrified aggregate, and therefore was exempt from regulation under the RCRA and permitting requirements as a hazardous waste incinerator under applicable federal and state environmental laws. The EPA contended that Marine Shale was a "sham-recycler" subject to the regulation and permitting requirements as a hazardous waste incinerator under the U.S. Resource Conservation and Recovery Act ("RCRA"), that its vitrified aggregate by-product was a hazardous waste, and that Marine Shale's continued operation without required permits was illegal. Litigation between the EPA and Marine Shale began in 1990 and continued until July 1996, when the U.S. Fifth Circuit Court of Appeals ordered Marine Shale to shut down its operations. 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 Clean Harbors was never a customer of Marine Shale. A Safety-Kleen subsidiary was, however, a Marine Shale customer and has been named a PRP. 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. The Company has joined with other parties 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, 2013 and December 31, 2012, the amount of the Company's reserves relating to the Marine Shale site were $4.5 million and $4.4 million, respectively. Certain Other Third Party Sites. At 11 of the 120 third party sites, Clean Harbors has an indemnification agreement with ChemWaste, a former subsidiary of Waste Management, Inc., and at five additional of those third party sites, Safety-Kleen has a similar indemnification agreement with McKesson Corporation. These agreements indemnify the Company (which now includes Safety-Kleen) with respect to any liability at the 16 sites for waste disposed prior to the Company's (or Safety-Kleen's) acquisition of the former subsidiaries of Waste Management or McKesson which had shipped wastes to those sites. Accordingly, Waste Management or McKesson are paying all costs of defending those subsidiaries in those 16 cases, including legal fees and settlement costs. However, there can be no guarantee that the Company's ultimate liabilities for those 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. Except for the indemnification agreements which the Company holds from ChemWaste and McKesson, the Company does not have an indemnity agreement with respect to any of the 120 third party sites discussed above. In addition to the Wichita Property, the BR Facility and Marine Shale, Clean Harbors has 12 sites at which it believes its potential liability could exceed $100,000. 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, 2013 and December 31, 2012, there were five 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 will, individually or in the aggregate, not have a material effect on its financial condition, results of operations or cash flows.

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, 2013 and December 31, 2012, the Company had recorded reserves of $41.8 million and $38.6 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, 2013 and December 31, 2012, the Company also believed that it was reasonably possible that the amount of these potential liabilities could be as much as $3.4 million and $3.5 million more, respectively. 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, 2013, the $41.8 million of reserves consisted of (i) $35.1 million related to pending legal or administrative proceedings, including Superfund liabilities, which were included in remedial liabilities on the consolidated balance sheets and (ii) $6.7 million primarily related to federal and state enforcement actions, which were included in accrued expenses on the consolidated balance sheets.

As of September 30, 2013, the principal legal and administrative proceedings in which the Company was involved, or which had been terminated during 2013, 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. By 1972, groundwater contamination had been identified, and the Quebec government provided an alternate water supply to the municipality of Ville Mercier.

In 1999, Ville Mercier and three neighboring municipalities filed separate legal proceedings against the Mercier Subsidiary and the Government of Quebec. The lawsuits assert that the defendants are jointly and severally responsible for the contamination of groundwater in the region, which they claim caused each municipality to incur additional costs to supply drinking water for their citizens since the 1970's and early 1980's. The four municipalities claim a Canadian dollar ("CDN") 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 more recent Notice notifies the Mercier Subsidiary that, if the Mercier Subsidiary does not take certain remedial measures at the site, the Minister intends to undertake those measures at the site and claim direct and indirect costs related to such measures. 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, 2013 and December 31, 2012, the Company had accrued $13.9 million and $14.2 million, respectively, for remedial liabilities relating to the Ville Mercier legal proceedings.

Safety-Kleen Legal Proceedings. On December 28, 2012, the Company acquired Safety-Kleen and thereby became subject to the legal proceedings in which Safety-Kleen was a party on that date. In addition to certain Superfund proceedings in which Safety-Keen has been named as a potentially responsible party as described below under “Superfund Proceedings,” the principal such legal proceedings involving Safety-Kleen which were outstanding as of September 30, 2013 were as follows:

Product Liability Cases - Safety-Kleen is named as a defendant in various lawsuits that are currently pending in various courts and jurisdictions throughout the United States, including approximately 62 proceedings (excluding cases which have been settled but not formally dismissed) as of September 30, 2013, wherein persons claim personal injury resulting from the use of Safety-Kleen's parts cleaning equipment or cleaning products. These proceedings typically involve allegations that the solvent used in Safety-Kleen's parts cleaning equipment contains contaminants and/or that Safety-Kleen's recycling process does not effectively remove the contaminants that become entrained in the solvent during their use. In addition, certain claimants assert that Safety-Kleen failed to warn adequately the product user of potential risks, including an historic failure to warn that solvent contains trace amounts of toxic or hazardous substances such as benzene. Safety-Kleen maintains insurance that it believes will provide coverage for these claims (over amounts accrued for self-insured retentions and deductibles in certain limited cases), except for punitive damages to the extent not insurable under state law or excluded from insurance coverage. Safety-Kleen believes that these claims lack merit and has historically vigorously defended, and intends to continue to vigorously defend, itself and the safety of its products against all of these claims. Such matters are subject to many uncertainties and outcomes are not predictable with assurance. Consequently, Safety-Kleen is unable to ascertain the ultimate aggregate amount of monetary liability or financial impact with respect to these matters as of September 30, 2013. From December 31, 2012 to September 30, 2013, 26 product liability claims were settled or dismissed. Due to the nature of these claims and the related insurance, Safety-Kleen did not incur any expense as Safety-Kleen's insurance provided coverage in full for all such claims. Safety-Kleen may be named in similar, additional lawsuits in the future, including claims for which insurance coverage may not be available.

Fee Class Action Claims. In October 2010, two customers filed a complaint, individually and on behalf of all similarly situated customers in the State of Alabama, alleging that Safety-Kleen improperly assessed fuel surcharges and extended area service fees. Safety-Kleen disputes the basis of the claims on numerous grounds, including that Safety-Kleen has contracts with numerous customers authorizing the assessment of such fees and that in cases where no contract exists Safety-Kleen provides customers with a document at the time of service reflecting the assessment of the fee, followed by an invoice itemizing the fee. It is Safety-Kleen's position that it had the right to assess fuel surcharges, that the customers consented to the charges and that the surcharges were voluntarily paid by the customers when presented with an invoice. The lawsuit is still in its initial stages of discovery, with the focus being whether a class will be certified. The class certification-related fact discovery cutoff was September 4, 2013, and a hearing on class certification is now scheduled to be held in early to mid-2014. The plaintiff has filed a motion to extend the discovery cutoff and trial date, but the court has not ruled on these requests. In late June 2012, a nearly identical lawsuit was filed by the same law firm on behalf of a California-based customer. That lawsuit contends, under various state law theories, that Safety-Kleen impermissibly assessed fuel surcharges and late payment fees, and seeks certification of a class of California customers only. Safety-Kleen will assert the same defenses as in the Alabama litigation. In December 2012, a similar suit was filed by the same law firm on behalf of a Missouri-based customer which contends under various state law theories that Safety-Kleen impermissibly assessed fuel surcharges and seeks certification of a class of Missouri customers only. Safety-Kleen will assert the same defenses as in the Alabama and California cases. The Company is unable to ascertain the ultimate aggregate amount of monetary liability or financial impact with respect to these matters as of September 30, 2013, and no reserve has been recorded.

Superfund Proceedings

The Company has been notified that either the Company (which, since December 28, 2012, includes Safety-Kleen) 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 122 sites which are subject to or are proposed to become subject to proceedings under federal or state Superfund laws. Of the 122 sites, two involve facilities that are now owned by the Company and 120 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 120 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, six are currently requiring expenditures on remediation, 13 are now settled, and 16 are not currently requiring expenditures on remediation. The status of the two facilities owned by the Company (the Wichita Property and the BR Facility) are further described below.

The 120 Superfund sites described above include 69 sites for which the Company had been notified it is a PRP or potential PRP prior to the Company's acquisition of Safety-Kleen on December 28, 2012, and an additional 50 sites at which Safety-Kleen had been notified it is a PRP or potential PRP prior to such acquisition. The total number of Superfund sites at which the Company had at September 30, 2013 potential liability and the total dollar amount of such estimated liability relating to those sites as described above have been increased to reflect the additional potential Superfund liabilities to which the Company became subject as a result of the Safety-Kleen acquisition. One of the third party sites (the Marine Shale site) is further described below.

Wichita Property. The Company acquired in 2002 as part of the CSD assets a service center located in Wichita, Kansas (the "Wichita Property"). The Wichita Property is one of several properties located within the boundaries of a 1,400 acre state-designated Superfund site in an old industrial section of Wichita known as the North Industrial Corridor Site. Along with numerous other PRPs, the former owner executed a consent decree relating to such site with the U.S. Environmental Protection Agency (the "EPA"), and the Company is continuing its ongoing remediation program for the Wichita Property in accordance with that consent decree. The Company also acquired rights under an indemnification agreement between the former owner and an earlier owner of the Wichita Property, which the Company anticipates but cannot guarantee will be available to reimburse certain such cleanup costs.

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 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.

Marine Shale Site. Prior to 1996, Marine Shale Processors, Inc. ("Marine Shale") operated a kiln in Amelia, Louisiana which incinerated waste producing a vitrified aggregate as a by-product. Marine Shale contended that its operation recycled waste into a useful product, i.e., vitrified aggregate, and therefore was exempt from regulation under the RCRA and permitting requirements as a hazardous waste incinerator under applicable federal and state environmental laws. The EPA contended that Marine Shale was a "sham-recycler" subject to the regulation and permitting requirements as a hazardous waste incinerator under the U.S. Resource Conservation and Recovery Act ("RCRA"), that its vitrified aggregate by-product was a hazardous waste, and that Marine Shale's continued operation without required permits was illegal. Litigation between the EPA and Marine Shale began in 1990 and continued until July 1996, when the U.S. Fifth Circuit Court of Appeals ordered Marine Shale to shut down its operations.

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 Clean Harbors was never a customer of Marine Shale. A Safety-Kleen subsidiary was, however, a Marine Shale customer and has been named a PRP. 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. The Company has joined with other parties 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, 2013 and December 31, 2012, the amount of the Company's reserves relating to the Marine Shale site were $4.5 million and $4.4 million, respectively.

Certain Other Third Party Sites. At 11 of the 120 third party sites, Clean Harbors has an indemnification agreement with ChemWaste, a former subsidiary of Waste Management, Inc., and at five additional of those third party sites, Safety-Kleen has a similar indemnification agreement with McKesson Corporation. These agreements indemnify the Company (which now includes Safety-Kleen) with respect to any liability at the 16 sites for waste disposed prior to the Company's (or Safety-Kleen's) acquisition of the former subsidiaries of Waste Management or McKesson which had shipped wastes to those sites. Accordingly, Waste Management or McKesson are paying all costs of defending those subsidiaries in those 16 cases, including legal fees and settlement costs. However, there can be no guarantee that the Company's ultimate liabilities for those 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. Except for the indemnification agreements which the Company holds from ChemWaste and McKesson, the Company does not have an indemnity agreement with respect to any of the 120 third party sites discussed above. In addition to the Wichita Property, the BR Facility and Marine Shale, Clean Harbors has 12 sites at which it believes its potential liability could exceed $100,000.

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, 2013 and December 31, 2012, there were five 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 will, individually or in the aggregate, not have a material effect on its financial condition, results of operations or cash flows.