Wastewater pretreatment.
San Antonio City Code § 34-473
in effectSec. 34-473. - Wastewater pretreatment.
(1) Pretreatment facilities. Users shall provide wastewater treatment as necessary to comply with this division and shall achieve compliance with all categorical pretreatment standards, local limits, and the prohibitions set out in section 34-472(1) of this division within the time limitations specified by EPA, the state, or the control authority, whichever is more stringent. Any facilities necessary for compliance shall be provided, operated, and maintained at the user's expense. Detailed plans describing such facilities and operating procedures shall be submitted to the department for review, and shall be acceptable to the division before such facilities are constructed. The review of such plans and operating procedures shall in no way relieve the user from the responsibility of modifying such facilities as necessary to produce a discharge acceptable to the control authority under the provisions of this division.
(2) Additional pretreatment measures.
(a) Whenever deemed necessary, the control authority may require users to restrict their discharge during peak flow periods, designate that certain wastewater be discharged only into specific sewers, relocate and/or consolidate points of discharge, separate sewage wastestreams from industrial wastestreams, and such other conditions as may be necessary to protect the POTW and determine the user's compliance with the requirements of this division.
(b) The control authority may require any person discharging into the POTW to install and maintain, on their property and at their expense, a suitable storage and flow-control facility to ensure equalization of flow. A wastewater discharge permit may be issued solely for flow equalization.
(c) Types of traps, sumps, interceptors and/or filters such as, but not limited to, lint, grease, oil, grit and sand shall be provided by the user when, in the opinion of the control authority, they are necessary for the proper handling of wastewater containing grease and oil, or grit; except that such interceptors shall not be required for residential users. All interception units shall be of type and capacity approved by the control authority and shall be so located to be easily accessible for cleaning and inspection. Such interceptors shall be installed, inspected, cleaned, and repaired regularly, as needed, by the user at their expense. Refer to the liquid waste transportation regulations, section 34-518(1)(c) for specific guidelines pertaining to the maintenance of such interceptors and/or sumps.
(d) Users with the potential to discharge flammable substances may be required to install and maintain an approved combustible gas detection meter.
As specified in the user's permit or this division, the industrial user shall effectively monitor the operation and efficiency of all pretreatment facilities, and the quantity and quality of the treated discharge emanating from the user's facility. Samples and measurements taken shall be representative of the monitored activity. Monitoring for the parameters indicated in an industrial user's permit or in this division must be conducted according to test procedures approved under 40 CFR 136 and 40 CFR 403.
(e) Dental industrial users must install, operate, and maintain an amalgam separator that meets the following requirements:
(i) Compliant with either the American National Standards Institute (ANSI) American National Standard/American Dental Association (ADA) Specification 108 for Amalgam Separators (2009) including Technical Addendum (2011), or the International Organization for Standardization (ISO) 11143 Standard (2008), or subsequent versions so long as that version requires amalgam separators to achieve at least a ninety-five (95) percent removal efficiency. Compliance must be assessed by an accredited testing laboratory under ANSI's accreditation program for product certification or a testing laboratory that is a signatory to the International Laboratory Accreditation Cooperation's Mutual Recognition Arrangement. The testing laboratory's scope of accreditation must include ANSI/ADA 108-2009 or ISO 11143.
(ii) The amalgam separator(s) must be sized to accommodate the maximum discharge rate of amalgam process wastewater.
(iii) A DIU subject to this ordinance that operates an amalgam separator that was installed at a dental facility prior to June 14, 2017, satisfies the requirements of paragraphs (e)(i) and (ii) of this section until the existing separator is replaced as described in paragraph (e)(v) of this section or until the effective date of this ordinance, whichever date is sooner.
(iv) The amalgam separator(s) must be inspected in accordance with the manufacturer's operating manual to ensure proper operation and maintenance of the separator(s) and to confirm that all amalgam process wastewater is flowing through the amalgam retaining portion of the amalgam separator(s).
(v) In the event that an amalgam separator is not functioning properly, the amalgam separator must be repaired consistent with manufacturer instructions or replaced with a unit that meets the requirements of paragraphs (e)(i) and (ii) of this section as soon as possible, but no later than ten (10) business days after the malfunction is discovered by the dental discharger, or an agent or representative of the dental discharger.
(vi) The amalgam retaining units must be replaced in accordance with the manufacturer's schedule as specified in the manufacturer's operating manual or when the amalgam retaining unit has reached the maximum level, as specified by the manufacturer in the operating manual, at which the amalgam separator can perform to the specified efficiency, whichever comes first.
(vii) For multiple offices located in a single building or complex sharing plumbing and vacuum systems (such as a school or dental complex) the DIUs may be able to install a larger separator rather than each office individually. Individual compliance reports are still required.
(3) Slug control plan. Within one (1) year of the effective date of the IU permit issuance date the control authority shall evaluate whether each significant industrial user needs a plan to control slug discharges. The control authority may require any user to develop, submit for review, and implement such a plan. In the event of a slug discharge by the IU, the facility will be required to revise, update the slug control plan and perform necessary upgrades to prevent reoccurrence. A plan shall address, at a minimum, the following:
(a) Description of discharge practices, including nonroutine batch discharges;
(b) Description of stored chemicals;
(c) Procedures for immediately notifying the control authority of any accidental or slug discharge, as required by sections 34-473(4) and 34-473(5) of this division, including any discharge that would result in a violation under 40 CFR 403.5(b) with procedures for followup written notification within five (5) calendar days, and
(d) Procedures to prevent adverse impact from any accidental or slug discharge. Such procedures include, but are not limited to, inspection and maintenance of storage areas, handling and transfer of materials, loading and unloading operations, control of plant site runoff, worker training, building of containment structures or equipment, measures for containing toxic organic pollutants, including solvents, and/or measures and equipment for emergency response.
(4) Reporting of slug/accidental discharges. In the case of a slug discharge, including any accidental spill or noncustomary batch discharges, the user shall notify the department and the appropriate water recycling center immediately by telephone and provide the following information:
(a) Time of discharge.
(b) Location of the discharge.
(c) Type of waste.
(d) Concentration and volume discharged.
(e) Corrective actions taken.
(f) Water recycling center receiving the waste.
Within five (5) calendar days following an accidental or slug discharge, the user shall submit to the control authority, or to the designated representative, a written report describing the cause of the discharge and the measures to be taken by the user to prevent similar future occurrences. The results of the report will be documented and available to the control authority upon request. Such notification shall not relieve the user of any responsibility for, expense, loss, damage, or other liability which may be incurred as a result of damage to the POTW, the environment or any other damage to person or property; nor shall such notification relieve the user of any fines, penalties, or other liability which may be imposed by this division or other applicable law. Failure to notify the director of a slug or accidental discharge may result in legal action or discontinuation of service; and may be deemed a separate violation of this division.
(5) Toxic organic management plan. All industrial users in the electroplating, metal finishing, copper forming, aluminum forming, coil coating and electrical and electronic components categories may submit a toxic organic management plan (TOMP) in lieu of annual monitoring for total toxic organics (TTO) as referenced in 40 CFR 413.03(b), 40 CFR 433.12(b) and 40 CFR 469.13(b) respectively. Specifically after initial monitoring in year one (1) the TTO monitoring in years two (2), three (3), four (4) and five (5) of the permit cycle may be waived by the control authority upon approval and proper implementation of the TOMP. After approval the TOMP will be incorporated by reference as a narrative BMP into the discharge permit. The plan must specify at a minimum the following:
(a) A complete inventory of all toxic organic chemicals, defined in this division as TTO, with corresponding MSDS sheets in use or identified through sampling and analysis of the wastewater from regulated process operations detected above 0.01 mg/l (Organic constituents of trade-name products should be obtained from the appropriate suppliers as necessary). All analyses must conform with 40 CFR Part 136 Methods.
(b) Descriptions of the methods of disposal other than dumping used for the inventoried compounds, such as reclamation, contract hauling, or incineration;
(c) The procedures for ensuring that the regulated toxic organic pollutants do not spill or routinely leak into process wastewaters, floor drains, non-contact cooling water, groundwater, surface waters; i.e., spill prevention, control and countermeasures (SPCC) plan; or any other location which allows discharge of the compounds; and
(d) Determinations or best estimates of the identities and approximate quantities of toxic organic pollutants used in as well as discharged from the regulated manufacturing processes. Compounds present in wastestreams that are discharged to sanitary sewers may be a result of regulated processes or disposal, spills, leaks, rinse water carryover, air pollution control, and other sources. The Control Authority reserves the right to verify compliance with the TTO requirement through its own sampling program.
(6) Notice to employees. All industrial users shall take necessary and reasonable measures to insure that all appropriate employees are advised of the notification procedure to be used in the event of an accidental or slug discharge.
(Ord. No. 81771, § 2(App. I), 3-2-95; Ord. No. 85765, § 1, 3-20-97; Ord. No. 99480, § 1(Exh. 1), 7-22-04; Ord. No. 2014-06-19-0472, § 1(Exh. A), 6-19-14; Ord. No. 2019-02-14-0123, § 1(Att. I), 2-14-19)
Source: City of San Antonio, City Code, City Charter and Unified Development Code (Municode Library, library.municode.com)URL: https://library.municode.com/tx/san_antonio/codes/code_of_ordinances?nodeId=PTIICO_CH34WASE_ARTVSETRTRDI_DIV3INWA_S34-473WAPRFetched: 10/27/2026