Document ID: EPA-HQ-OAR-2012-0360-0101
Agency: epa
Document Type: Supporting & Related Material
Title: 
Posted Date: 2015-03-18T04:00Z

MEMORANDUM

Date:		July 23, 2014

Subject:	Report of June 24, 2014 Site Visit to Clean Harbors in Deer Park, Texas

From:		Alden West, EC/R Incorporated 
		Lesley Stobert, EC/R Incorporated
		
To:		Paula Hirtz, EPA/OAQPS

This memorandum summarizes the visit to the Clean Harbors facility in Deer Park, Texas that was conducted on June 24, 2014. The purpose of this visit was to better understand the processes used in the Offsite Waste and Recovery Operations (OSWRO) industry, the controls in place to reduce hazardous air pollutants (HAP) emissions, and the characteristics of the emission points at this facility. This information will assist the EPA in the promulgation of amendments to the emission standards for the OSWRO industry.  

A background discussion of this project is provided, followed by an overview of the facility, a description of the off-site waste operations at the facility, and a summary of emission sources at the facility. The final section includes a summary of action items resulting from the meeting with Clean Harbors. 

	The participants in the site visit included the following:
      Ana Woods, Clean Harbors
      Paula Hirtz, U.S. EPA/OAQPS
      Lesley Stobert, EC/R Incorporated
      Alden West, EC/R Incorporated
      
BACKGROUND

Section 112(d) of the Clean Air Act requires the EPA to develop standards for each major source category listed under section 112(c). These technology-based standards are often referred to as maximum achievable control technology, or MACT, standards. The National Emissions Standards for Hazardous Air Pollutants (NESHAP) for Off-site Waste and Recovery Operations (OSWRO) were promulgated on July 1, 1996 (61 FR 34139) and codified at 40 CFR part 63, subpart DD. The Clean Harbors facility in Deer Park, TX is subject to subpart DD because it receives certain wastes from off-site locations for storage and treatment, recovery or disposal.

Section 112 of the Clean Air Act contains provisions requiring the EPA to periodically revisit the technology-based standards. Specifically, section 112(d)(6) states that the EPA shall review these standards and revise them "as necessary (taking into account developments in practices, processes, and control technologies)" no less frequently than every eight years. The second stage in the review process focuses on reducing any remaining (i.e., "residual") risk according to CAA section 112(f). Section 112(f)(2) directs the EPA to assess the risk remaining (residual risk) after the application of MACT standards and promulgate additional standards as necessary to provide an ample margin of safety to protect public health, or to prevent, taking into consideration costs, energy, safety, and other relevant factors, an adverse environmental impact. On May 30, 2014, the EPA proposed amendments to the OSWRO MACT standards to address the results of the residual risk and technology review (RTR) conducted under the Clean Air Act.

A site visit of the Clean Harbors facility was conducted to better understand the current processes and control technologies in the OSWRO industry before promulgation of final amendments to the OSWRO MACT standards. As part of the RTR process, the EPA is seeking additional information to improve the Agency's understanding of the OSWRO processes and emission points, to improve the data used in site-specific emission profiles and to better characterize the maximum risks to surrounding populations as a result of activities at OSWRO facilities. Further, the May 30, 2014 proposal includes new provisions that may change the way certain OSWRO sources are required to operate. This site visit was conducted to better understand the technical and operational implications of these changes based on current processes observed at the facility and discussions with facility personnel. 

PLANT SITE OVERVIEW
      
The Clean Harbors facility is located east of Houston in Deer Park, Texas. The facility is exclusively operated for the management of offsite-waste by incineration in a kiln. Ancillary units at the facility include a landfill, a wastewater treatment plant, and storage/processing units. Types of wastes managed by the facility include Resource Conservation and Recovery Act (RCRA) hazardous waste, polychlorinated biphenyls (PCBs), soils regulated by the Animal and Plant Health Inspection Service (APHIS) of the Department of Agriculture, Drug Enforcement Administration (DEA)-controlled substances, infection wastes, and non-regulated wastes.
      	
PROCESS DESCRIPTION

As noted above, the processes of interest at this site are those regulated by the OSWRO MACT standards.  The description provided below is a summary developed from materials provided during the site visit and from notes taken based on discussions with Clean Harbors personnel. 

When waste is first received at Clean Harbors it goes through a pre-acceptance procedure, including a document review and sampling, if required. Ten percent of drums (55 gal) received are sampled and most bulk containers are sampled, unless exempted. Examples of sampling exemptions include wastes that are extremely toxic or are typical/frequently received. Exemptions and other guidance on waste sampling and analysis are outlined in the facility's waste analysis plan (WAP), which is required by RCRA. The constituents of the waste are predetermined by the generator and sampling is done to confirm that the specified profile is accurate. Characteristics of the waste that are sampled include BTU content, metals, polyaromatic hydrocarbons (PAHs), viscosity, water activity and PH. Containers are tracked using a unique bar code identifier and by monitoring the weight through each feed port to the kilns.

Typical waste streams received by Clean Harbors include contaminated process wastewaters, oils, spent flammable solvents, organic and inorganic laboratory chemicals, paint residues, debris from toxic or reactive chemical cleanups, off-spec commercial products, cylinders and labpacks. Wastes are received in many forms, including solids (in drums, buckets, boxes or containers), sludges (in tank trucks, bins, vacuum boxes or drums), liquids (in drums or other containers, tank trucks, rail tank cars or bins), and gases (in metal cylinders). Waste is stored and processed in a variety of ways depending on its composition and state of matter. In general, bulk containers (i.e., roll-off boxes) are stored outside and smaller containers are stored inside. 

Clean Harbors operates several process tanks that consist of steel and/or concrete lined pits or tanks used for various waste processing operations, including repackaging of waste, mixing to achieve the optimal composition for incineration (e.g., high BTU content wastes mixed with low BTU content wastes), and waste feed to the incinerator using a clamshell bucket. Three waste mixing pits are located in a building designed as a permanent total enclosure, which is vented to an incinerator. 

Clean Harbors operates a tank farm for storage of liquid wastes. Wastes designated for unloading to a storage tank are first analyzed for compatibility with the existing material in the tank. All storage tanks are equipped with fixed roofs and nitrogen blankets to suppress emissions. Vapors originating from normal pressure fluctuations in the tank are routed through a liquid knock-out pot to an incinerator; a carbon bed is also installed for back-up emission control. All storage tanks are equipped with rupture discs to relieve emergency pressure buildup and high level/overflow alarms to prevent overfilling. Clean Harbors provided a list of all storage and process tanks, including tank ID, capacity, dimensions and other information. 

The incineration system consists of two units, Train I and Train II. Train I has a thermal capacity of 180 MMBtu/hr and consists of a 3.6 meter diameter rotary kiln, a horizontal afterburner, and a liquids burner. Train II has thermal capacity of 213.5 MMBtu/hr and consists of a 4.4 meter diameter rotary kiln, a rotary reactor, and a vertical afterburner. Diesel fuel, used oil, or natural gas is supplemented if there is not adequate BTU content to operate the incinerator. After incineration, the exhaust gas flows through a saturator to rapidly cool the gas and minimize dioxin formation. Each train is equipped with back-end pollution control systems, including  packed tower condensers, a venturi scrubber, a wet electrostatic precipitator and a selective catalytic reduction system.

Clean Harbors operates an onsite landfill for disposal of residual waste from the incineration process. A wastewater treatment plant is also operated to manage aqueous byproducts from back-end emission control units, including saturators and scrubbers. 

EMISSION SOURCES

Emission sources at Clean Harbors include tanks, containers, fugitives, transfer systems, and control devices.

Storage tank emissions can occur from the evaporation of liquid wastes placed in the tank. The storage tanks at Clean Harbors are equipped with fixed roofs and nitrogen blankets to reduce evaporation of tank contents to the atmosphere. Tanks are also equipped with vents that provide relief from fluctuations in tank pressure resulting from normal operating conditions such as filling/emptying and changes in atmospheric temperature. Vapors released by the pressure/vacuum valves are routed through a liquid knock-out pot to the secondary combustion chamber of one of the hazardous waste incinerators. The incinerator is considered a control device under the OSWRO MACT standards. Storage tanks at Clean Harbors are also equipped with emergency relief valves that release tank vapors to the atmosphere if excessive pressure or vacuum develops. In the event of an emergency, all tank pumps can be shut off from the main control room or by a field operator. 

Emissions from containers can occur if the container is leaking or if the cover of a container is removed for sampling or other purposes. All containers at the facility, including drums and bulk containers, are controlled by a cover and closure device (e.g., a lid on a drum or secured tarp on a roll-off box). 

Process tanks are another source of emissions at the Clean Harbors facility. The building surrounding the three mixing/material processing pits (T-1001-1, 2 and 3) is designed as a permanent total enclosure (PTE). The building is vented to an incinerator, and a carbon bed absorption unit serves as a backup air pollution control device if both incinerators are out of service. The main doors of the building are opened when necessary to add or remove waste. During the site visit, a noticeable odor was observed in this area indicating the presence of chemical vapors. There are additional processing pits for operations other than mixing, such as receipt of bulk solids and clamshell feed to the incinerator. No emission controls are identified for these additional pits in the information provided by Clean Harbors.  

Clean Harbors operates numerous valves, pump seals, flanges, open-ended lines, and other equipment components that could leak hazardous vapors to the atmosphere. Clean Harbors complies with the RCRA air emission standards for equipment leaks (40 CFR part 264 subparts BB and CC).

Transfer systems are a potential source of emissions at Clean Harbors and are subject to the OSWRO MACT standards. Transfer systems operated at the facility include pumps and conveyors. 

As mentioned, Clean Harbors operates a wastewater treatment plant (WWTP) to manage aqueous byproducts. The WWTP is not subject to RCRA or OSWRO standards because it exclusively treats waste generated onsite. Based on a review of the Title V operating permit for Clean Harbors, the facility is subject to the process wastewater provisions of the Hazardous Organic NESHAP (HON) at 40 CFR part 63 subpart G. 

ACTION ITEMS

* EPA agreed to resend the ICR to Clean Harbors, including to Ana Woods who is currently the environmental coordinator for the site. 
* EPA requested HAP emissions from OSWRO operations at the facility, including the latitude and longitude of their operations. Clean Harbors agreed to send this information by the end of the public comment period. 
* EPA agreed to send the link to the website for the OSWRO proposal and a link to the site where Clean Harbors can access and revise their modeling data.