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Chemical Evaluations and Discharge Permits

 

  1. What is the division’s chemical evaluation process for discharge permits?
    • The chemical evaluation process allows the division to evaluate the proposed use and discharge of chemicals and determine if the current permit conditions are protective enough or if a modification to the permit is needed. During a permit renewal, the division evaluates and reviews all chemicals used and proposed for use that could be discharged. 
    • The chemical evaluation process is not necessarily always required when a facility uses a new chemical. See #2 below (When do you need to start the chemical evaluation process)
    • The chemical evaluation process requires you to fill out and submit this Request for Chemical Evaluation form. There is also an optional request for permit modification section. It is your decision whether to request a permit modification at the same time. 
    • At the end of the chemical evaluation process, there are four possible division decisions:
      • A finding that your permit is already protective enough to address the chemical
      • A finding that a modification is needed. Modifications could include: 
        • To add monitoring
        • To add WET testing
        • To add specific limits 
    • Denial because the chemical addition will lead to a violation of numeric or narrative standards.
    • Denial due to a lack of information.
    • Note: Once you submit a request for chemical evaluation, the Division will conduct that evaluation, including requiring the necessary information from you. This is true even if you later claim that the chemical is not a significant change under Regulation 61.8(5) and an evaluation was not needed. 
  2. When do you need to start the chemical evaluation process?
    • If the chemical will significantly change the nature or increase the quantity of pollutants discharged or may result in noncompliance with permit requirements, per Colorado Discharge Permit System Regulation 61.8(5)(h), which requires WQCD notification under those circumstances.  
    • (For domestic WWTPs) In order to seek approval under Regulation 22. In this situation, filling out a chemical evaluation may be required in order to obtain a Water Quality Planning Target.
    • (For manufacturing, commercial, mining, and silvicultural dischargers) To notify the Division of a routine or frequent discharge of any toxic pollutant not limited in your permit if that discharge will exceed certain “notification levels” listed in Reg. 61.8(5)(k).
    • During a new permit application, permit renewal, general certification renewal, or permit modification if you would like your permit to authorize the use of chemicals. The permittee must include all chemicals proposed for use (existing and new) on the Request for Chemical Evaluation form.

  1. Basic requirements for filling out the form:
    • The form: https://cdphe.colorado.gov/wq-per-forms
    • Requires name of the chemical, the waste stream, operating dose, effluent concentration, all chemical components, breakdown products, and aquatic toxicity. 
    • If the information is not complete after the division reaches out, the evaluation may be denied.
    • The division cannot review chemical evaluation requests without all required information for the chemical components, including any proprietary components.
  2. Frequent speedbump in the chemical evaluation process: You have to provide ALL of the chemical components and breakdown products, even the inactive ones.
    • A designation of inactive is not relevant to a chemical being a pollutant of concern and needing to be evaluated. 
  3. Frequent speedbump in the chemical evaluation process: You want to use a proprietary chemical for which you don’t know all of the components.
    • Proprietary chemicals, even ones that are characterized as inactive ingredients, can lead to potential exceedances of water quality standards, harm aquatic life, or otherwise affect the protectiveness of the current permit. For instance, a recently proposed proprietary chemical contained acrylamide. 
    • Proprietary chemicals are likely to take longer to go through the chemical evaluation process. If you have a choice and you are limited for time, we encourage you to consider the use of non-proprietary chemicals.
    • As a first step, review the division’s list of the proprietary chemicals for which the division has the whole list of components. 
    • If the division does not already have all of the components, contact the manufacturer and ask that they send the information to you, or, if they prefer, directly to the division. 
      • The Division has developed an optional form that you can send to the manufacturer to request the proprietary chemical information that includes a summary of how the State of Colorado protects trade secrets and confidential commercial data like proprietary information.
  4. Frequent speedbump in the chemical evaluation process: You don’t have the aquatic toxicity for the chemical product.
    • A permittee may seek to use a chemical for which the Division does not have a water quality standard and where it is uncertain, prior to analysis, whether that chemical will be “harmful to the beneficial uses or toxic to humans, animals, plants, or aquatic life.” Reg. 31.11(1)(a)(iv) (the narrative surface water standard). 
    • The division may need to review WET testing results and other toxicity information in order to determine whether the chemical will harm aquatic life.
    • A permittee is using multiple chemicals with common constituents or pollutants of concern (e.g. using iron sulfate, magnesium sulfate, aluminum sulfate, etc. at the same time). The constituents (in this example, sulfate) should be aggregated to determine the representative effluent concentration for use in the toxicity test. 
    • There are a number of ways to provide aquatic toxicity information:
      • It may be listed on the MSDS. Note the MSDS needs to provide the toxicity for the whole chemical product, rather than selected components.
      • For renewal permits, a WET test of your current effluent if your facility currently uses the requested chemical product, at the same operating dose as identified in this form. Note that there may be instances that additional aquatic toxicity data would be required to complete the chemical evaluation (for instance, if the existing permit has acute WET, but the renewal requires chronic WET).
      • Conduct an aquatic toxicity test on the chemical product using effluent, to identify the LC50, IC25 or NOEC (as appropriate for the facility).  It is not necessary to also conduct a toxicity test on an effluent sample without the chemical product.
      • Conduct an aquatic toxicity test on the chemical product using lab water, to identify the LC50, IC25 or NOEC (as appropriate for the facility). 
      • Conduct a bench scale toxicity test on an effluent sample, with the chemical product at the proposed operating dosage, or effluent concentration (as applicable) to identify the LC50, IC25 or NOEC (as appropriate for the facility).  It is not necessary to also conduct a toxicity test on an effluent sample without the chemical product.

      • Demonstrate the pollutants of concern have an effluent concentration of 0 or nondetect (Detection limit must be lower than permit limit, potential limit or toxicity concentration). 

        Methods used to determine effluent concentration may include dilution or a BioWin model for domestic facilities. Any model would require additional communication with the division, and may trigger the need for additional aquatic toxicity. 

  5. Frequent speedbump in the chemical evaluation process: You provided toxicity tests results and the tests were of each chemical product separately, however the permittee did not provide the effluent concentration for the product (only for the components).
    • The division will request more information to confirm that the effluent concentration is below the toxicity results. 

  1. A list of the proprietary chemicals for which the division currently knows all of the components
    • Note that you may still need to provide aquatic toxicity information and/or WET testing. 
  2. A list of toxicity tests the division has on file that were taken directly on the chemical product (diluted with lab water)

  1. Why does the Division do chemical evaluations?
    • Adding new chemicals without authorization can be a violation of the Colorado Water Quality Control Act and the Clean Water Act. 
      • For instance, a permittee may seek to use a chemical at an increased concentration, and the new concentration that may be “harmful to the beneficial uses or toxic to humans, animals, plants, or aquatic life.” Reg. 31.11(1)(a)(iv).
    • Adding new chemicals can lead to potential exceedances of water quality standards, harm aquatic life, or otherwise affect the protectiveness of the current permit. This is true even for widely used ones that may seem harmless at first glance.
      • Examples: 
        • A permittee may seek to discharge a chemical for which the receiving water body is impaired, like adding copper sulfate to control algae.
        • A permittee may seek to discharge a chemical (existing or new) that results in a concentration of a pollutant in the effluent so that a limit is needed. This has come up with sulfate and acrylamide.
        • A permittee may seek to discharge a chemical containing phosphate in a concentration that affects whether the facility can receive Regulation 85’s dilution exception for nutrient standards. 
        • A permittee may seek to discharge seemingly harmless chemicals such as sodium, calcium or magnesium based alkalinity and the associated salts. These could affect aquatic toxicity (they are often identified as the reasons for Whole Effluent Toxicity (WET) testing failures), could contribute to EC/SAR or TDS, and may contain trace metals.
  2. Why would you need more monitoring or limits if it’s a chemical that will be at least partially consumed in the treatment process?
    • A key part of permit limits is to make sure that the treatment is working - so our Reasonable Potential policy explicitly talks about including monitoring or limits for pollutants that are controlled through the treatment process.  
  3. Aren’t these chemicals already regulated by the Toxic Substances Control Act or the Federal Insecticide, Fungicide, and Rodenticide Act?
    • Some are, some are not. In any case, a chemical’s regulation under those laws is not the same as ensuring that a discharge in the concentrations proposed by a permittee will meet water quality standards and not lead to aquatic toxicity.
  4. Why hasn’t the Division allowed an exception for polymers?
    • The term polymer includes a wide variety of chemicals, which may have different properties, aquatic toxicity, and pollutants of concern. There is no basis under the Colorado Water Quality Control Act for treating polymers (or what is more accurately used in wastewater: flocculants and coagulants) as a class differently than other chemicals. 
  5. Why have different permittees had to do different things? For example, some permittees have been required to submit acute WET data and others have had to submit chronic WET data? And some permits have needed to be modified when a chemical was added and some have been left untouched when the same chemical was added?
    • The division requires acute or chronic data for the product, correlated to the type of WET testing in the permit, or the type of WET testing based on the IWC for the facility if there is not WET in the permit.
    • Other requirements will depend upon current permit limits, how much dilution a facility has, how the chemical affects the effluent as a whole, the nature of the effluent, and the receiving water.  

  1. How do I know if my permit covers chemical additions or treatment chemicals?
    • The factsheet lists the chemicals disclosed by the permittee and evaluated and covered by the permit.  
    • During the permit renewal process, chemicals are re-evaluated.  Permittees are encouraged to submit chemical evaluation forms with the renewal application or in an application supplement to streamline the permitting action during the permit renewal process.
    • For administratively continued permits, where the permits section has completed a chemical evaluation request and determined that the administratively continued permit provides coverage for the chemical use, the permits section will write a memo stating the specific chemical use is covered by the permit.  
  2. I have a general permit certification (e.g., COG590000, COG589000, COG591000) and I want to obtain permit coverage for chemical additions or a treatment chemical that is not addressed in the current permit.  How do I do that?  
    • Submit a chemical evaluation form and check the permit modification box on the form.
  3. I have an individual permit that is not administratively continued and I want to obtain permit coverage for chemical additions or a treatment chemical that is not addressed in the current permit. How do I do that?
    • Submit a chemical evaluation form and check the permit modification box on the form.
  4. I have an individual permit for a facility permitted to discharge 1 MGD or more that is administratively continued and I want to obtain permit coverage for a treatment chemical that is not addressed in the current permit. How do I do that?
    • Administratively continued permits cannot be modified and major facility permit renewals follow a basin schedule. If you determine that the chemical addition is a significant change in accordance with Reg 61.8(5)(h), you can submit the chemical evaluation form.  https://cdphe.colorado.gov/wq-per-forms The permits section will review information and determine if the current permit provides coverage for the chemical.
    • The limited scope PEL process is also available to determine future permitting limits for proposed chemicals.
  5. I have an individual permit for a facility permitted to discharge < 1 MGD that is administratively continued and I want to obtain permit coverage for a treatment chemical that is not addressed in the current permit. How do I do that?
  6. I have a WQPT/PEL and I have new or different chemicals to evaluate that were not addressed in the WQPT/PEL. How do I do that?
    • Submit a chemical evaluation form and check the permit modification box on the form. Include the permit number or PEL# to be modified on the chemical evaluation form.
  7. I have WET monitoring in my current permit, do I have permit coverage for chemicals that are not addressed in the permit documents?  Can I add new chemicals without a chemical evaluation? 
    • The permits section would need to evaluate the chemical to determine if a permit provides coverage for chemicals that are not specifically identified in the permit documents. See Question 1. 
  8. What is Reg 61.8(5)(h) and what does it mean?
    • Reg 61.8(5)(h) states:

      • The permittee shall notify the Division, in writing, of any planned physical alterations or additions to the permitted facility. Notice is required only when:

        (i) The alteration or addition could significantly change the nature or increase the quantity of pollutants discharged; or
        (ii) The alteration or addition results in a significant change in the permittee's sludge use or disposal practices, and such alteration, addition, or change may justify the application of permit conditions that are different from or absent in the existing permit, including notification of additional use or disposal sites not reported pursuant to an approved land application plan.

    • This section of the Regulation allows the permittee to assume the legal risk of making this determination.  The division does not review or validate this permittee determination outside of the permit renewal process. During the permit renewal process, the permit section will evaluate all chemicals and require the permittee to submit the documentation that was the basis of a previous ‘insignificant change’ determination by the permittee.  
    • The permittee has the limited scope PEL process available (for an administratively continued, major facility permit) to obtain a chemical evaluation from the permits section.
  9. I want to add chemicals commonly used in water and wastewater treatment that were not previously disclosed or identified in the permit.  Do I need a chemical evaluation and approval to obtain permit coverage?
    • Yes
  10. I want to add chemicals commonly used in water and wastewater treatment that were not previously disclosed or identified in the permit. Is this a significant change? 
    • Maybe. See Permitting Scenario FAQs 8 and 11.
  11. Can I say that the chemical addition is an ‘insignificant change’ according to Reg 61.8(5)(h) and also use that statement in a Reg 22 process?
    • Reg 61 - Colorado Discharge Permit System Regulation is a permitting regulation.
    • It is the Engineering Section's decision whether to accept a permittee's Reg  61.8(5)(h) determination for a Reg 22 - Site Location and Design Regulations for Domestic Wastewater Treatment Works process.
    • Refer to Regulations:
  12. What are the permit documents or permitting actions that the division uses to document chemical determinations?
    • See Questions 1-6.  Chemicals can be evaluated and documented in permits for current coverage or WQPTs, including PELs, to use in a Reg 22 Site Application process. Please see the WQPT webpage for additional information:
  13. Does a WQPT (permits first with delayed effective date or a PEL) that includes a chemical evaluation also provide permit coverage for a chemical that is not addressed in the permit?
    • No. A WQPT is a planning document (Permit with a delayed effective date, PEL, WQPT memo) used in the Site Application process.  It does not affect or modify the permit. See Question 1.

Questions