62-625.420. Removal Credits

(1) Introduction. Rule 62-625.420, F.A.C., does not apply where the Department is acting as the control authority.

(a) Any public utility receiving wastewater from a categorical industrial user may, at the control authority’s discretion and subject to the conditions of this section, grant removal credits to reflect removal by the WWF of pollutants specified in the categorical pretreatment standard. The control authority may grant a removal credit equal to or, at its discretion, less than its consistent removal rate. Upon being granted a removal credit, each affected industrial user shall calculate its revised discharge limits in accordance with paragraph (c), below. Removal credits shall only be given for indicator or surrogate pollutants regulated in a categorical pretreatment standard if the categorical pretreatment standard so specifies.

(b) Conditions for authorization to give removal credits. A control authority is authorized to give removal credits only if all of the following conditions are met:

1. The control authority requests, and receives authorization from the Department to give, a removal credit in accordance with the requirements and procedures specified in subsection (4), below.

2. Consistent removal determination. The WWF demonstrates and continues to achieve consistent removal of the pollutant in accordance with subsection (2), below.

3. Pretreatment program. The public utility has a pretreatment program approved by the Department in accordance with Rule 62-625.510, F.A.C.

4. Biosolids requirements. The granting of removal credits will not cause the WWF to violate the local, State, and Federal requirements which apply to the biosolids management method chosen by the WWF. Alternatively, the WWF can demonstrate to the Department that (even though it is not presently in compliance with applicable domestic wastewater residual requirements) it will be in compliance when the industrial user (to whom the removal credit would apply) is required to meet its categorical pretreatment standard, as modified by the removal credit. Removal credits may be made available for the following:

a. Any pollutant listed in subsections 62-625.880(2) and (3), F.A.C., for the use or disposal practice employed by the WWF, when the requirements in Chapter 62-640, F.A.C., for that practice are met;

b. Arsenic, Beryllium, Cadmium, Chromium, Lead, Mercury and Nickel, when incinerated, when the concentration for these pollutants does not exceed the requirements of 40 C.F.R. Part 503.43, (“Incineration: Pollutant Limits” codified as of July 1, 2020, which is hereby adopted and incorporated by reference http://www.flrules.org/Gateway/reference.asp?No=Ref-13511). A copy of this document may be obtained by contacting the Wastewater Management Program, M.S. 3545, 2600 Blair Stone Road, Tallahassee, Florida 32399-2400;

c. Any pollutant listed in subsection 62-625.880(4), F.A.C., for the use or disposal practice employed by the WWF, when the concentration for the pollutant listed in subsection 62-625.880(4), F.A.C., does not exceed the specified concentration; or

d. For any pollutant in biosolids, when the WWF disposes all of its biosolids in a municipal solid waste landfill that meets the criteria in Chapter 62-701, F.A.C.

5. Permit limitations. The granting of removal credits shall not cause a violation of the WWF’s permit limitations or conditions. Alternatively, the WWF can demonstrate to the Department that (even though it is not presently in compliance with applicable limitations and conditions in its permit) it will be in compliance when the industrial user (to whom the removal credit would apply) is required to meet its categorical pretreatment standard, as modified by the removal credit.

(c) Calculation of revised discharge limits. Revised discharge limits for a specific pollutant shall be derived by use of the following formula:

where
y	=	Revised discharge limit for the specified pollutant (expressed in same units as x).
x	=	Pollutant discharge limit specified in the applicable categorical pretreatment standard.
r	=	Removal credit for that pollutant as established under subsection (2), below (percentage removal expressed as a proportion, i.e., a number between 0 and 1).

(2) Establishment of removal credits; demonstration of consistent removal. Influent and effluent operational data demonstrating consistent removal, or other information as provided for in paragraph (g), below, which demonstrates consistent removal of the pollutants for which discharge limit revisions are proposed, shall be provided to the Department. These data shall meet the following requirements:

(a) Representative data: seasonal. The data shall be representative of yearly and seasonal conditions to which the WWF is subjected for each pollutant for which a discharge limit revision is proposed.

(b) Representative data: quality and quantity. The data shall be representative of the quality and quantity of normal effluent and influent flow if such data can be obtained. If such data are unobtainable, alternate data or information may be presented for approval to demonstrate consistent removal as provided for in paragraph (g), below.

(c) Sampling procedures: composite.

1. The influent and effluent operational data shall be obtained through 24-hour flow-proportional composite samples. Sampling shall be done manually or automatically, and discretely or continuously. For discrete sampling, at least 12 aliquots shall be composited. Discrete sampling shall be flow-proportioned either by varying the time interval between each aliquot or the volume of each aliquot. All composites must be flow-proportional to each stream flow at the time of collection of the influent aliquot or to the total influent flow since the previous influent aliquot. Volatile pollutant aliquots must be combined in the laboratory immediately before analysis.

2. Sampling frequency and historical data.

a. Twelve samples shall be taken at approximately equal intervals throughout one full year. Sampling must be evenly distributed over the days of the week so as to include non-workdays as well as workdays. If the Department determines that this sampling is not representative of the actual operation of the WWF, the Department shall notify the WWF with an explanation of why it has come to this determination. The control authority shall submit, within 30 days of receipt of the Department notice, an alternative sampling schedule. The Department shall approve the alternative sampling schedule if it is representative of the operation of the WWF. The alternative sampling schedule shall not be implemented until written Department approval is obtained.

b. As an alternative, a WWF may utilize an historical data base amassed prior to the effective date of this chapter. In order for the historical data base to be approved, it must present a statistically valid description of daily, weekly, and seasonal WWF loadings and performance for at least one year.

3. The Department shall require that each effluent sample be taken approximately one detention time later than the corresponding influent sample when failure to do so would result in an unrepresentative portrayal of actual WWF operation. The detention period is to be based on a 24-hour average daily flow value. The average daily flow used will be based upon the average of the daily flows during the same month of the previous year.

(d) Sampling procedures: Grab. Where composite sampling is not an appropriate sampling technique, grab samples shall be taken to obtain influent and effluent operational data. Collection of influent grab samples should precede collection of effluent samples by approximately one detention period. The detention period is to be based on a 24-hour average daily flow value. The average daily flow used shall be based upon the average of the daily flows during the same month of the previous year. Grab samples shall be required, for example, where the parameters being evaluated are those, such as cyanide and phenol, which may not be held for any extended period because of biological, chemical, or physical interactions which take place after sample collection and affect the results.

(e) Analytical methods. The sampling referred to in paragraphs (c) and (d), above, and an analysis of these samples, shall be performed in accordance with Chapter 62-160, F.A.C.

(f) Calculation of removal. All data acquired under the provisions of this rule must be submitted to the Department. Removal for a specific pollutant shall be determined for each sample either by measuring the difference between the concentrations of the pollutant in the influent and effluent of the WWF and expressing the difference as a percent of the influent concentration, or by using other data or procedures subject to concurrence by the Department as provided for in paragraph (g), below.

(g) All sample data obtained for the measured pollutant during the time period prescribed in this section, must be reported to the Department and used in computing consistent removal. If a substance is detectable in the influent but not in the effluent, the effluent level shall be assumed to be the method detection limit, and those data may be used by the WWF at its discretion if the method detection limit meets the requirements of Rule 62-4.246, F.A.C. If the substance is not detectable in the influent, the data shall not be used to calculate consistent removal. Where the number of samples with concentrations equal to or above the method detection limit is between 8 and 12, the average of the lowest 6 removals shall be used. If there are less than 8 samples with concentration equal to or above the method detection limit, the Department shall require alternate means for demonstrating consistent removal.

(3) Provisional credits. For pollutants which are not being discharged currently (i.e., new or modified facilities, or production changes), the control authority may apply for authorization to give removal credits prior to the initial discharge of the pollutant. Consistent removal shall be based provisionally on data from treatability studies or demonstrated removal at other comparable treatment facilities where the quality and quantity of influent are similar. Within 18 months after the commencement of discharge of pollutants in question, consistent removal must be demonstrated in accordance with subsection (2), above. If, within 18 months after the commencement of the discharge of the pollutant in question, the WWF cannot demonstrate consistent removal in accordance with subsection (2), above, the authority to grant provisional removal credits shall be terminated by the Department in accordance with paragraph (5)(d), below.

(4) Control authority request for authorization to give removal credits and Department review.

(a) Any control authority that wants to give a removal credit must request authorization from the Department.

(b) The request for authorization to give removal credits (or modify existing ones) shall be submitted in writing by the control authority to the Department.

(c) A control authority may request authorization to give or modify removal credits at any time.

(d) The request for authorization to give removal credits must be supported by the following information:

1. List of pollutants. A list of pollutants for which removal credits are proposed.

2. Consistent removal data. The data required in subsection (2), above.

3. Calculation of revised discharge limits. Proposed revised discharge limits for each affected subcategory of industrial users calculated in accordance with paragraph (1)(c), above.

4. Biosolids management certification. A specific description of the WWF’s current methods of using or disposing of its biosolids and a certification that the granting of removal credits will not cause a violation of the biosolids requirements identified in subparagraph (1)(b)4., above.

5. Permit limit certification. A certification that the granting of removal credits will not cause a violation of the WWF’s permit limits and conditions as required in subparagraph (1)(b)5., above.

(e) Department review. The Department shall review the control authority’s request for authorization to give or modify removal credits in accordance with the procedures of Rule 62-625.510, F.A.C., and shall, in no event, have more than 180 days from public notice of the request to complete review.

(f) EPA review of State removal credit approvals. The EPA Regional Administrator will review and approve submissions for authority to grant removal credits.

(g) Nothing in these regulations precludes an industrial user or other interested party from assisting the control authority in preparing and presenting the information necessary to request authorization.

(h) Upon Department and EPA approval of a control authority’s request to grant removal credits, the WWF’s permit shall be revised in accordance with Rule 62-620.325, F.A.C., to include the revised discharge limits and any additional monitoring and reporting requirements.

(5) Continuation and withdrawal of authorization.

(a) Effect of authorization. Once a control authority has received authorization to grant removal credits for a particular pollutant regulated in a categorical pretreatment standard, it may automatically extend that removal credit to the same pollutant when it is regulated in other categorical standards, unless granting the removal credit will cause the WWF to violate the requirements identified in subparagraph (1)(b)4., above, or its permit limits and conditions as required by subparagraph (1)(b)5., above. If a control authority elects at a later time to extend removal credits to a certain categorical pretreatment standard, industrial subcategory or one or more industrial users that initially were not granted removal credits, it must notify the Department prior to granting the removal credit.

(b) Inclusion in WWF permit. Once authority is granted, the removal credits shall be included in the WWF’s permit and shall become an enforceable requirement of the WWF’s permit. The removal credits shall remain in effect for the term of the WWF’s permit, provided the WWF maintains compliance with the conditions specified in paragraph (d), below.

(c) Compliance monitoring. Following authorization to give removal credits, a control authority shall continue to monitor and report on the WWF’s removal capabilities at such intervals as specified in the WWF’s permit, but in no case less than once per year. A minimum of one representative sample per month during the reporting period is required, and all sampling data must be included in the control authority’s compliance report.

(d) Modification or withdrawal of removal credits.

1. Notice of control authority. The Department shall notify the control authority if, on the basis of pollutant removal capability reports received pursuant to paragraph (c), above, or other relevant information available to it, the Department determines:

a. That one or more of the discharge limit revisions made by the control authority no longer meets the requirements of this section, or

b. That such discharge limit revisions are causing a violation of any conditions or limits contained in the WWF’s permit.

2. Corrective action. If appropriate corrective action is not taken within a reasonable time, not to exceed 60 days, the Department shall either withdraw such discharge limits or require modifications in the revised discharge limits. An extension to the 60 day time period shall be granted if the control authority or industrial user submits a written request to the Department that demonstrates that more time is necessary to undertake appropriate corrective action and that the time extension will not have any adverse environmental impacts.

3. Public notice of withdrawal or modification. The Department shall not withdraw or modify revised discharge limits unless it first notifies, in writing, the control authority and all industrial users to whom revised discharge limits have been applied, of the reasons for such withdrawal or modification. The Department shall publish a notice of withdrawal or modification of revised discharge limits in a newspaper(s) of general circulation within the jurisdiction served by the WWF that meets the requirements of Sections 50.011 and 50.031, F.S., and shall provide an opportunity for an administrative hearing. Following such notice and withdrawal or modification, all industrial users to whom revised discharge limits had been applied, shall be subject to the modified discharge limits or the discharge limits prescribed in the applicable categorical pretreatment standards, as appropriate, and shall achieve compliance with such limits in accordance with subsection 62-625.410(3), F.A.C.

Rulemaking Authority 403.061(7), (31), 403.0885 FS. Law Implemented 403.0885 FS. History–New 11-29-94, Amended 1-8-97, 5-10-10, 9-20-21.