Managing Hazardous Waste

We strengthen regulations and streamline waste management

Transportable Treatment Unit Operating Under Conditionally Exempt-Specified Wastestreams Fact Sheet

May 2005*


The Department of Toxic Substances Control (DTSC) developed this fact sheet to assist owners and operators of Transportable Treatment Units (TTUs) in complying with Conditionally Exempt-Specified Wastestreams (CESW) laws and regulations. CESW regulations are part of a tiered permitting system for hazardous waste treatment in California. This fact sheet describes the requirements for TTU owners and operators who would like to treat hazardous waste under the CESW tier.

This fact sheet applies to TTUs only. For information regarding treatment in Fixed Treatment Units (FTUs), please see DTSC’s fact sheet on FTUs titled Fixed Treatment Unit Operating Under Conditionally Exempt-Small Quantity Treatment. Definitions of the terms used in this fact sheet are below.

This fact sheet will help you determine if you are eligible to operate a TTU under CESW. It will also help you understand the various administrative and technical operating requirements for conducting onsite treatment of hazardous waste. However, be advised that this fact sheet contains general information only and is not a substitute for the actual laws, the Health and Safety Code, division 20, chapter 6.5, and California Code of Regulations (Cal. Code Regs.), title 22, division 4.5.

What is a TTU?

Transportable Treatment Units (TTUs) are mobile equipment that perform onsite treatment of hazardous waste using proven treatment processes. Unlike Fixed Treatment Units (FTUs), TTUs are not permanently stationed at a single facility and may operate at numerous facilities. TTUs may be used to conduct onsite treatment under the CESQT tier if the owner or operator complies with applicable State laws and regulations.

Background on California’s Tiered Permitting System

The Wright-Polanco-Lempert Hazardous Waste Treatment Permit Reform Act of 1992 established a five-tiered program for authorizing the treatment and storage of hazardous waste at many businesses required to have State authorization, but not federal authorization (i.e., authorization under the federal Resource Conservation and Recovery Act (RCRA)). This five-tiered program matches the regulatory requirements to the degree of risk posed by the facility’s activities.

The permitting tiers consist of: Full Permit, Standardized Permit, Permit by Rule (PBR), Conditionally Authorized (CA), and Conditionally Exempt (CE). They are arranged in descending order of regulatory oversight.

  • The Full Permit tier allows treatment and storage of RCRA and California only (non-RCRA) hazardous waste pursuant to 40 Code of Federal Regulations (C.F.R.), parts 264 and 270, and California Code of Regulations, title 22, §66264.1 et seq., and §66270.1 et seq. It includes all facilities requiring a RCRA permit (such as incinerators and land disposal facilities), and selected non-RCRA activities. TTUs are eligible for authorization under this tier.
  • The Standardized Permit tier allows offsite treatment and storage of non-RCRA and RCRA-exempt hazardous waste (Health & Safety Code §25201.6). It includes, but is not limited to, recyclers, oil transfer stations, and precious metals recyclers. Note: TTUs are eligible for authorization under this tier.
  • The Permit By Rule tier allows onsite treatment of non-RCRA and RCRA-exempt hazardous waste (Cal. Code Regs., tit. 22, §67450.11). This tier is for more hazardous and higher volume wastestreams and processes than the two lower tiers. Note: TTUs are eligible for authorization under this tier.
  • The Conditionally Authorized tier allows onsite treatment of non-RCRA and RCRA-exempt hazardous waste (Health & Safety Code §25200.3). This tier is limited to single-hazard wastes and treatment in the unit cannot exceed 5,000 gallons or 45,000 pounds in a calendar month. However, there is no volume limit for treatment of specified dilute aqueous, acidic, alkaline, or oily wastes. Note: TTUs are not eligible for authorization under this tier.
  • The Conditionally Exempt tier allows onsite treatment of non-RCRA and RCRA-exempt hazardous waste (Health & Safety Code §25201.5(a) and (c), §25201.14, and §25144.6(c)). This tier is for smaller quantities or less risky waste and treatment methods. It includes: Conditionally Exempt-Small Quantity Treatment, Conditionally Exempt-Specified Wastestreams, Conditionally Exempt-Commercial Laundries, and Conditionally Exempt-Limited. Note: TTUs are eligible for authorization only under the Conditionally Exempt-Small Quantity Treatment, and Conditionally Exempt-Specified Wastestreams tiers.

Am I Eligible to Treat Waste under CESW?

You are eligible to treat waste under CESW if your wastestreams and treatment processes are listed in Health and Safety Code, §25201.5(c). A list of those wastestreams and treatment processes is included in this fact sheet. Additionally, to be eligible:

  • You may only treat waste that is generated onsite;
  • You may not treat waste that requires a federal hazardous waste treatment permit under RCRA;
  • You may not treat waste in landfills, surface impoundments, injection wells, waste piles, land treatment units, or thermal destruction units (Health & Safety Code §25201.5(b)); and
  • There is only one volume limitation for CESW. The separation of oil/water mixtures and separation sludges is limited to an average of less than 25 barrels (42 gallons) of oil recovered per month.

Conditionally-Exempt Specified Wastestream Requirements

If you intend to operate under the CESW tier, you must comply with the following requirements:

Unit Specific Notification: Prior to placing your TTU into service, you must notify DTSC, by submitting the information required in Health and Safety Code section 25201.5(d)(7)(A). To comply with this requirement, submit a completed Transportable Treatment Unit Permit by Rule/Conditional Exemption Unit-Specific Notification (DTSC Form 1199, (1/96)), for each TTU that you operate. You must submit the forms at least 60 days before beginning the first waste treatment. If you demonstrate good cause, DTSC can shorten the time period between notification and treatment.

Complete and sign the notifications, and mail them to the address below, by certified mail, with return receipt requested.

DTSC Headquarters
Attn. TTU Notifications
P.O. Box 806
Sacramento, CA 95812-0806

Note: For expedited review, submit a site specific notification at the same time with your unit specific notification(s).

Site Specific Notification: Each time your TTU operates at a different site, you must notify DTSC by submitting the information required in Health and Safety Code §25201.5(d)(7)(A). To comply with this requirement, submit a completed Transportable Treatment Unit  Conditional Exemption Site-Specific Notification (DTSC Form 1198 (1/96). Forms are available from DTSC Headquarters by calling (916) 323-2678, or writing to:

DTSC Headquarters
Attn. TTU Notifications
P.O. Box 806
Sacramento, CA 95812-0806

Mail the form to the above address, by certified mail, with return receipt requested.

If a change occurs to any information contained in your most recent notification, submit an amended notification within 30 days of the change. Always keep copies of the notifications that you submitted and any DTSC acknowledgments that you receive.

Generator Operating Standards: If you operate a TTU under CESW and generate hazardous waste, you must comply with hazardous waste generator standards in California Code of Regulations, title 22, division 4.5, chapter 12. For an overview of these standards, see DTSC’s fact sheets titled “Hazardous Waste Generator Requirements Fact Sheet” (January 2002) and “Accumulating Hazardous Wastes at Generator Sites Fact Sheet” (January 2002).

Operating Records: If you generate hazardous waste, you must maintain all records required by the hazardous waste generator standards. In addition, all owners and operators of TTUs operating under CESQT must maintain the following records onsite for three years (Health & Safety Code §25201.5(d)):

  • Written operating instructions for the treatment unit and a record of the dates, amounts, and types of wastes treated, such as a treatment log book;
  • A written inspection schedule and log of inspections conducted; and
  • If discharging your waste to the sewer, records to demonstrate that you are in compliance with all applicable requirements for pretreatment and discharge.

Containers: If you treat hazardous waste in containers, you must comply with the standards for container storage and transfer activities specified in California Code of Regulations, title 22, division 4.5, chapter 14, §66264.175, and chapter 15, article 9 (commencing with §66265.170). Requirements include proper management for all container transfer and storage areas, proper management of the containers to prevent leaks, and weekly inspections of the storage areas.

Tanks: If you treat hazardous waste in tanks (onground or aboveground) you must comply with the standards for storage and treatment of hazardous wastes in tanks applicable to generators.

Large Quantity Generators: If you generate 1,000 kilograms (approx. 2,200 pounds) or more of hazardous waste per month, you must comply with the standards for storage and treatment of hazardous wastes in tanks set forth in California Code of Regulations, title 22, division 4.5, chapter 15, article 10, §66265.190-66265.199, except 66265.197. Most new and existing tanks must undergo an integrity assessment and have secondary containment before being placed into service. The assessment must be in writing and certified by a qualified professional engineer (Cal. Code Regs., title 22, §66265.192(a)). Tanks must be reassessed every five years.

Several small categories of existing tanks may be temporarily exempt from secondary containment requirements (for details, see Cal. Code Regs., title 22, §66265.193). Those tanks must undergo an integrity assessment every year. The assessment must be in writing and certified by a professional engineer (see Cal. Code Regs., title 22, §66265.191).

Small Quantities Generators: If you generate less than 1,000 kilograms (approx. 2,200 lbs) of waste per month, and the total waste accumulated onsite never exceeds 6,000 kilograms, you must comply with the federal tanks standards incorporated into the California regulations by reference (see Cal. Code Regs, title 22, §66262.34(d)). The significant difference is that you are not required to provide secondary containment and engineer certifications for your tank system.

Ancillary Equipment: You are not required to have secondary containment for ancillary equipment for a tank or container treating hazardous waste if the ancillary equipment has undergone an integrity assessment pursuant to California Code of Regulations, title 22, §66265.191 every two years from that the date that retrofitting requirements would otherwise apply (Health & Safety Code §25201.5(e)(1)).

Financial Assurance: You are exempt from financial assurance requirements (e.g., having to provide third party liability coverage for environmental accidents and financial assurance for closure (Health & Safety Code §25245.4(c))).

Fees: If you operate a TTU under CESW, you will be billed an annual CESW fee. The fee is assessed by the Board of Equalization as specified in the Revenue and Taxation Code, §43152.10. The fee for 2004 was $38 per treatment unit. You will be billed annually, until the unit has been certified closed according to Health and Safety Code §25201.5(j), and you submit the closure certification to DTSC. Also, if you operate during any part of a calendar year, you may be billed a CESW fee for the entire year.

Closure of Treatment Units: You are not required to prepare and maintain a written closure plan. However, you must comply with all the requirements for proper closure as specified in Health and Safety Code §25201.5(d)(8). Remove and decontaminate all waste residues, containment system components, soils, and other structures or equipment contaminated with hazardous waste from the unit. Remove the unit from service in a manner that minimizes the need for further maintenance and eliminates any escape of hazardous wastes, hazardous constituents, leachate, contaminated runoff, or waste decomposition products to the environment after treatment is ceased. If hazardous waste contamination of the site has occurred, you must notify DTSC. You should also notify the local Certified Unified Program Agency (CUPA).

When you permanently cease operation of a TTU, you must notify DTSC in writing that you have properly closed the unit, pursuant to Health and Safety Code §25201.5(d)(8). The closure notification should include the following information:

  • Company name
  • Address
  • EPA ID number
  • TTU number
  • Tier of authorization
  • Date of closure

Corrective Action: You are exempt from Phase I Environmental Assessment Checklist requirements (Health & Safety Code §25201.14(c)(5)).

Public Notice and Local Land Use: For the purposes of local land use decisions, your facility is not considered a hazardous waste treatment facility if your facility is authorized under CESW. Also, you are not required to publish a public notice regarding your treatment operation.

Disclosure Requirement: You are exempt from the requirement to provide a disclosure statement regarding past environmental violations, compliance orders, convictions or judgments (Health & Safety Code §25200.4).

Inspection Programs: DTSC may inspect your TTU at any time. At a minimum, your TTU will be inspected within two years of your initial notification, and then every three years thereafter (Health & Safety Code §25201.4(b)(2)).

Training Classes: California Compliance School offers training on Tiered Permitting. The class focuses on how to comply with hazardous waste management requirements. Call California Compliance School at 1-800-337-1422, or access its website for information regarding class times, locations, cost, and enrollment instructions. California Compliance School also offers four generator modules, with classes available at central locations statewide or at your worksite.

CESW Wastestreams: The following are the eligible wastestreams and treatment processes for transportable treatment units operating under CESW (Health & Safety Code, §25201.5 (c)):

  1. Mixing or curing resins in accordance with the manufacturer’s instructions, including the mixing or curing of multicomponent and preimpregnated resins.
  2. Treating a container of 110 gallons or less capacity for the purposes of emptying the container as specified in §66261.7 of title 22, California Code of Regulations, or treating the inner liners from containers that once held hazardous materials. The containers cannot be constructed of wood, paper, cardboard, fabric or any other similar absorptive material. You can treat using the following technologies, if the treated containers and rinseate are managed in compliance with specified requirements:
    1. Rinsing the containers or inner liner with a suitable liquid capable of dissolving or removing the hazardous constituents which the container held.
    2. Using physical processes (such as crushing, shredding, grinding, or puncturing) that change only the physical properties of the container or inner liner, if the container of inner liner is first rinsed and the rinseate removed.
  3. Drying special wastes, as classified in California Code of Regulations, title 22, §66261.124, by pressing the wastes to remove water or by passive or heat-aided evaporation.
  4. Magnetic separation or screening to remove components from special wastes, as classified in California Code of Regulations, title 22, §66261.124.
  5. Neutralizing hazardous wastes which are corrosive or toxic solely due to the presence of acidic or alkaline material from food or food byproducts, and acidic or alkaline wastes other than wastes containing nitric acid, at SIC Code Major Group 20, food and kindred product facilities (as defined in Health & Saf. Code, §25501(p)). The following two conditions must be met:
    1. The neutralization process does not result in the emission of volatile hazardous waste constituents or toxic air contaminants; and
    2. The neutralization process is required in order to meet discharge or other regulatory requirements.
  6. Gravity separation of the following wastestreams (You must use impervious tanks or containers constructed of noncorrosive materials, may not use heat, and may not add chemicals other than flocculants and demulsifiers):
    1. Settling of solids from waste where the resulting aqueous stream is not hazardous; and
    2. Separation of oil/water mixtures and separation sludges, if the average oil recovered per month is less than 25 barrels.

(Note: some used oil/water separation may be eligible for regulation under the Conditionally Exempt Limited tier. Also, certain phase separation processes do not require authorization if exempted from the definition of treatment in §25123.5 of the Health and Safety Code).

  1. The generator is a laboratory which is State certified or operated by an education institution and treats wastewater generated onsite solely as a result of analytical testing, or is a laboratory, which treats less than one gallon of hazardous waste, which is generated onsite, in any single batch. You must comply with the following conditions:
    1. The wastewater is hazardous solely due to corrosivity or toxicity resulting only from acidic or alkaline material, or is excluded from the definition of hazardous waste in California Code of Regulations, title 22, §66261.3(a)(2)(E).
    2. The treatment complies with all applicable pretreatment requirements, the waste neutralization takes place in elementary neutralization units, wastes to be neutralized do not contain more than 10% acid or base concentration by weight, and vessels and piping for neutralization are compatible with the range of temperature and pH levels. You must ensure that the treatment does not result in emissions of volatile hazardous waste or toxic air contaminants. (Note: no authorization is required if the laboratory treatment complies with Health and Safety Code, §25200.3.1).
  2. Treatment of hazardous waste carried out in quality control/quality assurance laboratories at facilities other than offsite hazardous waste facilities, if the waste is not an extremely hazardous waste, and is listed in California Code of Regulations, title 22, §67450.11 as eligible for treatment under Permit by Rule. (Note: No authorization is required if the laboratory treatment complies with Health and Safety Code §25200.3.1).
  3. Certified Technology: You may treat any wastestream and treatment technology combination certified by DTSC as appropriate for authorization under CESW, pursuant to Health and Safety Code, §25201.5.


  • Certified Unified Program Agency (CUPA): A CUPA is a local agency, such as a county, city, or Joint Powers Agency, that is certified by the Secretary (Secretary for Environmental Protection) to implement the Unified Program within a jurisdiction as specified in Health and Safety Code, div. 20, ch. 6.11. The CUPAs are responsible for consolidating, coordinating, and making consistent many environmental programs.
  • Fixed Treatment Unit (FTU): An FTU is any equipment that performs hazardous waste treatment that is permanently stationed at a single facility regardless of the period or frequency of treatment.
  • Onground Tank: A device meeting the definition of “tank,” situated in such a way that the bottom of the tank is on the same level as the adjacent surrounding surface so that the external tank bottom cannot be visually inspected (see Cal. Code Regs., title 22, §66260.10).
  • Phase I Environmental Assessment: A preliminary site assessment based on reasonably available knowledge of the facility, including, but not limited to, historical use of the property, prior releases, visual and other surveys, records, consultant reports, and regulatory agency correspondence.
  • Transportable Treatment Unit (TTU): A TTU is any mobile equipment that performs treatment, is transported to a facility to perform a treatment, and is not permanently stationed at a single site.
  • Treatment: Any method, technique, or process which is not otherwise excluded, or which is designed to change the physical, chemical, or biological character or composition of the hazardous waste or material it contains, or which removes or reduces its harmful properties or characteristics for any purpose. If the activity that you are conducting is consistent with this definition, you are required to obtain a permit or a grant of authorization through your CUPA. However, if your activity is not considered regulated treatment, you do not need a permit or grant of authorization. The following activities do not require a permit or a grant of authorization (see Health & Safety Code §25123.5):
    • Sieving or filtering liquid hazardous waste to remove solid fractions, without added heat, chemicals, or pressure, as the waste is added to or removed from a storage or accumulation tank or container (sieving or filtering does not include adsorption, reverse osmosis, or ultra-filtration).
    • Phase separation of hazardous waste during storage or accumulation in tanks or containers, if the separation is unaided by the addition of heat or chemicals. If the phase separation occurs at a commercial offsite permitted storage facility, all phases of the hazardous waste must be managed as hazardous waste after separation.
    • Combining two or more wastestreams that are compatible into a single tank or container if both of the following conditions apply:
      1. The wastestreams are being combined solely for the purpose of consolidated accumulation or storage or consolidated offsite shipment, and they are not being combined to meet a fuel specification or to otherwise be chemically or physically prepared to be treated, burned for energy value, or incinerated.
      2. The combined wastestream is managed in compliance with the most stringent of the regulatory requirements applicable to each individual wastestream.
    • Evaporating water from hazardous wastes in tanks or containers, such as breathing and evaporation through vents and floating roofs, without adding pressure, chemicals, or heat other than sunlight or ambient room lighting or heating.
    • Combining glutaraldehyde or orthophthaladehyde, used by medical facilities to disinfect medical devices, with formulations containing glycine as the sole active chemical, if the process is carried out onsite. (This activity is only allowed for medical facilities.)
  • Unified Program: The Unified Hazardous Waste and Hazardous Materials Management Regulatory Program is commonly referred to as the Unified Program. The Unified Program consolidated several major environmental management and emergency management programs at the local government level to help businesses subject to waste management requirements comply with the legal requirements (Health & Safety Code, div. 20, ch. 6.11).
  • Unit: A unit is a tank, container, or a combination of tanks or tank systems and/or containers located together that are used in sequence to treat or accumulate one or more compatible hazardous wastestreams. The devices are either plumbed together or otherwise linked so as to form one treatment system (see Cal. Code Regs., title 22, §66260.10).

More Information & Contacts

For assistance or additional information, please contact the DTSC Office nearest you. You can also contact our Regulatory Assistance Officers at:

Toll-Free in CA: 800-728-6942 or 800 72-TOXIC
Outside CA: 916-324-2439

For a list of all DTSC offices, go to our Office Address and Phone Numbers web page.


This fact sheet does not replace or supersede relevant statutes and regulations. The information contained in this fact sheet is based upon the statutes and regulations in effect as of the date of the fact sheet. Interested parties should keep apprised of subsequent changes to relevant statutes and regulations.