United States Environmental Protection Agency Region 2 Caribbean Environmental Protection Division City View Plaza ll-Suite 7000, #48 Rd. 165 km 1.2 Guaynabo, Puerto Rico 00968-8069 FACT SHEET NATIONAL POLLUTANT DISCHARGE ELIMINATION SYSTEM Enrique Ortega PERMIT No. PR0022616 This Fact Sheet sets forth the principle facts and technical rationale that serve as the legal basis forthe requirements of the accompanying draft permit. The draft permit has been prepared in accordance with Clean Water Act (CWA) section 402 and its implementing regulations at Title 40 of the Code of Federal Regulations (CFR), Parts 122 through 124, and the Water Quality Certificate (WQC) issued by the Puerto Rico Department of Natural and Environmental Resources (DNER) pursuant to CWA section 401 requirements. Pursuant to 40 CFR 124.53, the Commonwealth of Puerto Rico must either grant a certification pursuant to CWA section 401 or waive this certification before the U.S. Environmental Protection Agency (EPA) may issue a final permit. On November 17, 2022, DNER provided in the WQC that the allowed discharge will not cause violations to the applicable water quality standards at the receiving water body if the limitations and monitoring requirements in the WQC are met. In accordance with CWA section 401, EPA has incorporated the conditions of the WQC into the draft permit. The WQC conditions are discussed in this Fact Sheet and are no less stringent than allowed by federal requirements. Additional requirements might apply to comply with other sections of the CWA. Review and appeals of limitations and conditions attributable to the WQC were made through the applicable procedures of the Commonwealth of Puerto Rico and not through EPA procedures. Background A. Permittee and Facility Description The Puerto Rico Aqueduct and Sewer Authority (PRASA) (referred to throughout as the Permittee) has applied for renewal of its National Pollutant Discharge Elimination System (NPDES) permit. The Permittee is discharging pursuant to existing NPDES Permit No.PR0022616. The Permittee submitted Application Form 1 and Form 2C dated May 28, 2021 and applied for an NPDES permit to discharge treated wastewater from Enrique Ortega WTP, Toa Alta, PR, called the facility. The facility is classified as a major discharger by EPA in accordance with the EPA rating criteria. The Permittee owns and operates a water treatment plant (WTP). Attachment A of this Fact Sheet provides a map of the area around the facility and a flow schematic of the facility. The treatment system consists of the following: The Enrique Ortega WTP is a water supply that provides conventional treatment to raw water from the La Plata Lake to supply potable water to Bayamon, Toa Alta, Toa Baja and Naranjito. It has a capacity of 85 MGD (monthly average) and has a Sludge Treatment System (STS) to treat the filter backwashes and sedimentation tanks drains and discharge its effluent into Pinas creek. Water is processed through the following units: > Aeration Tanks > Coagulation & Flocculation Tank > Sedimentation Tanks > Filters > Sludge Treatment System also known as STS (1 Equalization Tank, 2 Clarifiers, Filter Presses and Sludge Drying Beds) NPDES Fact Sheet 1 ------- Puerto Rico Aqueduct and Sewer Authority NPDES NO. PR0022616 Enrique Ortega WTP > Chlorination System > Dechlorination System Sludge is thickened, dewatered and disposed in a landfill. Summary of Permittee and Facility Information Permittee Puerto Rico Aqueduct and Sewer Authority (PRASA) Facility contact, title, phone Mr. Edgardo Bermudez Valentin, Executive Director Compliance and Quality Control (787) 620-2277 Permittee (mailing) address Puerto Rico Aqueduct and Sewer Authority P.O. Box 7066 Barrio Obrero Station Santurce, Puerto Rico 00916-7066 Facility (location) address State Road 827, Km. 5.6, Pinas Ward Toa Alta, PR 00954 Type of facility WTP Pretreatment program N/A Facility monthly average flow 4.128 Facility design flow 10.82 MGD Facility classification Major B. Discharge Points and Receiving Water Information Wastewater is discharged from Outfall 001 to the earth channel tributary to Pinas Creek, a water of the United States. The draft permit authorizes the discharge from the following discharge point(s): Outfall Effluent description Outfall latitude Outfall longitude Receiving water name and classification 001 filters backwasher and sedimentation tanks drains 18°, 21', 19" N 66°, 13', 29" W earth channel tributary to Pinas Creek, Class SD waters As indicated in the Puerto Rico Water Quality Standards (PRWQS) Regulations, the designated uses for Class SD receiving waters include: > Use as a raw source of public water supply; and > Propagation and preservation of desirable species, including threatened or endangered species. CWA section 303(d) requires the Commonwealth of Puerto Rico to develop a list of impaired waters, establish priority rankings for waters on the list, and develop TMDLs for those waters. The receiving water has not been determined to have water quality impairments for one or more of the designated uses as determined by section 303(d) of the CWA. C. Mixing Zone/Dilution Allowance - N/A D. Compliance Orders/Consent Decrees NPDES Fact Sheet 2 ------- Puerto Rico Aqueduct and Sewer Authority NPDES NO. PR0022616 Enrique Ortega WTP The Permittee has a Consent Decree with the Agency (civil action Civil Action No 3:15-CV-02283(JAG)) in which the facility is included. This consent decree does not affect this permit action. E. Summary of Basis for Effluent Limitations and Permit Conditions - General The effluent limitations and permit conditions in the permit have been developed to ensure compliance with the following, as applicable: > Clean Water Act section 401 certification requirements; > NPDES regulations (40 CFR Part 122); and > PRWQS (August, 2022). PART I. RATIONALE FOR EFFLUENT LIMITATIONS AND MONITORING REQUIREMENTS CWA section 301(b) and 40 CFR 122.44(d) require that permits include limitations more stringent than applicable technology-based requirements where necessary to achieve applicable water quality standards. In addition, 40 CFR 122.44(d)(1)(i) requires that permits include effluent limitations for all pollutants that are or may be discharged at levels that cause, have the reasonable potential to cause, or contribute to an exceedance of a water quality criterion, including a narrative criterion. The process for determining reasonable potential and calculating water quality-based effluent limits (WQBELs) is intended to protect the designated uses of the receiving water, and achieve applicable water quality criteria. Where reasonable potential has been established for a pollutant, but there is no numeric criterion for the pollutant, WQBELs must be established using (1) EPA criteria guidance under CWA section 304(a), supplemented where necessary by other relevant information; (2) an indicator parameter for the pollutant of concern; or (3) a calculated numeric water quality criterion, such as a proposed state criterion or policy interpreting the state's narrative criterion, supplemented with other relevant information, as provided in 40 CFR 122.44(d)(1)(vi). The effluent limitations and permit conditions in the permit have been developed to ensure compliance with all federal and state regulations, including PRWQS. The basis for each limitation or condition is discussed below. A. Effluent Limitations The permit establishes WQBELs for several pollutants and the basis for these limitations are discussed below. 1. Flow: An effluent limitation for flow has been established in the permit. Monitoring conditions are applied pursuant to 40 CFR 122.21 (j)(4)(ii) and DNER's Water Quality Certificate. 2. Arsenic, Copper, Lead, Total Nitrogen, and Chromium VI: The effluent limitation is based on the water quality standards as specified in Rule 1303.1.1.1 of PRWQS, and the WQC. 3. 5-Day Biochemical Oxygen Demand (BODs): The effluent concentration and percent removal limitations are based on technology-based secondary treatment standards for publicly owned treatment works (POTWs) specified in 40 CFR 133.102(a). The permit also requires influent monitoring and reporting in accordance with 40 CFR 122.44(i) to meet the requirement of the percent removal limitation (see section C.1.—Monitoring Requirements— of this Part). 4. Color and Turbidity: The effluent limitation is based on the water quality criterion for Class SD waters as specified in Rule 1303.1 .B of PRWQS, and the WQC. 5. pH: The effluent limitation is based on the water quality standards as specified in Rule 1303.2.C.2.d of PRWQS, and the WQC. 6. Temperature: The effluent limitation for temperature is based on the water quality criterion for Class SD waters as specified in Rule 1303.1.D.1 of PRWQS, and the WQC. 7. Dissolved Oxygen (DO): The effluent limitation is based on the water quality criterion for Class SD waters as specified in Rule 1303.2.C.2.a. of PRWQS, and the WQC 8. Turbidity: The effluent limitation is based on the water quality criterion for Class SD waters as specified in Rule 1303.2.C.2.f. of PRWQS, and the WQC. 9. Taste and Odor Producing Substances: The effluent limitation is based on the water quality criterion for Class SD waters as specified in Rule 1303.2.D.2.h of PRWQS, and the WQC. NPDES Fact Sheet 3 ------- Puerto Rico Aqueduct and Sewer Authority NPDES NO. PR0022616 Enrique Ortega WTP 10. Suspended, Colloidal orSettleable Solids: The effluent limitation is based on the water quality standards as specified in Rule 1303.1 .E of PRWQS, and the WQC. 11. Solids and Other Matter: The effluent limitation is based on the water quality standards as specified in Rule 1303.1 .A of PRWQS, and the WQC. 12. Copper, Lead, Residual Chlorine, and Zinc: The effluent limitation is based on the water quality standards as specified in Rule 1303.1.J.1 of PRWQS, and the WQC. 11. Total Ammonia Nitrogen (TAN): The effluent limitation is based on the water quality criterion for Class SD waters as specified in Rule 1303.2 C.2.I of PRWQS, and the WQC. 12. Total Phosphorus: The effluent limitation is based on the water quality criterion for Class SD waters as specified in Rule 1303.2 C.2.n of PRWQS, and the WQC. B. Effluent Limitations Summary Table 1. Outfall Number 001 Parameter Units Effluent limitations Averaging period Highest Reported Value (1) Existing limits Final limits Basis Notes Arsenic Mg/i Daily maximum 1430.0 10 10 WQBEL (1) BOD5 mg/L Daily maximum 51.3 5.0 5.0 WQBEL (1) Color Pt-Co Units Daily maximum 15 15 15 WQBEL (1) Copper Mg/i Daily maximum 101 11 12.00 WQBEL (1) Chromium VI (Cr+6) Mg/i Daily maximum - - Monitor PRWQSR (2) Dissolved Oxygen mg/L Daily Minimum 7.50 >5 >5 WQBEL (1) Flow MGD Daily maximum 21.3 4.128 4.128 WQBEL (1) Lead Mg/L Daily maximum 51.6 4.0 4.40 WQBEL (1) pH su Daily min/maxim 6.0-10.1 6.0- 9.0 6.0- 9.0 WQBEL (1) Residual Chlorine Mg/L Daily maximum 60 11 11 WQBEL (1) Suspended, Colloidal or Setteable Solids ml/L Daily maximum 400 Monitor Monitor WQBEL (1) Temperature "C Daily maximum 29.6 32.2 °C max 30 °C max WQBEL (1) Total Ammonia Nitrogen (TAN) mg/L Daily maximum 4784 Monitor Monitor WQBEL (1) Total Nitrogen (TKN, N02, N03) Daily maximum 13790 Monitor Monitor WQBEL (1) NPDES Fact Sheet 4 ------- Puerto Rico Aqueduct and Sewer Authority Enrique Ortega WTP NPDES NO. PR0022616 Parameter Units Effluent limitations Averaging period Highest Reported Value (1) Existing limits Final limits Basis Notes Turbidity NTU Daily maximum 2000 50 50 WQBEL (1) Note: Dashes (-) indicate there are no effluent data, no limitations, or no monitoring requirements for this parameter. (1) Wastewater data from DMRs dated May 28, 2020 to May 28, 2022. (2) The permittee shall implement a monthly monitoring program using the analytical method approved by EPA with the lowest possible detection level, in accordance with Rule 1306.2(C) of the PRWQSR, as amended, for one (1) year period, after which they will be conducted annually. (3) No Net Addition Limitation - If the applicable water quality standard is not exceeded in the inlet, the established effluent limitation shall not be exceeded at the discharge point 001. - If the applicable water quality standard is exceeded in the inlet, the same measurement shall be achieved at the discharge point 001. In order to demonstrate compliance with the No Net Addition Limitation, influent (raw water from Rio La Plata) and effluent (filters backwash and sedimentation tanks drains) monitoring must be conducted at the frequency specified herein. The permitte shall take into consideration the residence time of the influent when scheduling influent and effluent monitoring. The permittee shall report the results of these measurements in the Discharge Monitoring Reports. Alternately, the permittee may forego influent monitoring and comply with the applicable water standard as effluent limitation at the end of the pipe of the discharge. 2. Outfall 001 Narrative Limitations a. The waters of Puerto Rico must not contain any substance, attributable to the discharge at such concentration which, either alone or as result of synergistic effects with other substances, is toxic or produces undesirable physiological responses in humans, fish, or other fauna or flora. b. The discharge must not cause the presence of oil sheen in the receiving water body. c. The waters of Puerto Rico must not contain floating debris, scum, or other floating materials attributable to discharges in amounts sufficient to be unsightly or deleterious to the existing or designated uses of the water body. d. Solids from wastewater sources must not cause deposition in or be deleterious to the existing or designated uses of the waters. e. Taste and odor-producing substances must not be present in amounts that will interfere with primary contact recreation, or will render any undesirable taste or odor to edible aquatic life. f. Except by natural causes, no heat may be added to the waters of Puerto Rico, which would cause the temperature of any site to exceed 86°F (30°C). C. Monitoring Requirements NPDES regulations at 40 CFR 122.48 require that all permits specify requirements for recording and reporting monitoring results. The Part III of the Permit establishes monitoring and reporting requirements to implement federal and state requirements. The following provides the rationale for the monitoring and reporting requirements for this facility. 1. Effluent Monitoring Requirements Effluent monitoring frequency and sample type have been established in accordance with the requirements of 40 CFR 122.44(i) and recommendations in EPA's TSD. Consistent with 40 CFR Part 136 monitoring data for toxic metals must be expressed as total recoverable metal. Effluent monitoring and analyses shall be conducted in accordance with EPA test procedures approved under 40 CFR Part 136, Guidelines Establishing Test Procedures for the Analysis of Pollutants Under the Clean Water Act, as amended. For situations where there may be interference, refer to Solutions to Analytical Chemistry Problems with Clean Water Act Methods (EPA 821-R-07-002). A licensed chemist authorized to practice the profession in Puerto Rico shall certify all chemical analyses. All bacteriological tests shall be certified by a microbiologist or licensed medical technologist authorized to practice the profession in Puerto Rico. NPDES Fact Sheet ------- Puerto Rico Aqueduct and Sewer Authority NPDES NO. PR0022616 Enrique Ortega WTP The sampling point for Outfall 001 shall be located immediately after the primary flow measuring device of the effluent of the treatment system. D. Compliance with Federal Anti-Backsliding Requirements and Puerto Rico's Anti-Degradation Policy Federal regulations at 40 CFR 131.12 require that state water quality standards include an anti-degradation policy consistent with the federal policy. The discharge is consistent with the anti-degradation provision of 40 CFR 131.12, 72 Federal Register 238 (December 12, 2007, pages 70517-70526) and DNER's Anti-Degradation Policy Implementation Procedure in Attachment A of PRWQSR. In addition, CWA sections 402(o)(2) and 303(d)(4) and federal regulations at 40 CFR 122.44(1) prohibit backsliding in NPDES permits. Further, the Region 2 Antibacksliding Policy provides guidance regarding relaxation of effluent limitations based on water quality for Puerto Rico NPDES permits. These anti-backsliding provisions require effluent limitations in a reissued permit to be as stringent as those in the previous permit with some exceptions where limitations may be relaxed. • The effluent limitations in the permit are at least as stringent as the effluent limitations in the existing permit, with the exception of effluent limitation for Chromium VI and Temperature. The effluent limitation for this pollutant is less stringent that those in the existing permit. This relaxation of effluent limitation is consistent with the anti-backsliding requirements of CWA section 401 (o), 40 CFR 122.44(1), EPA Region 2's Anti-backsliding Policy dated August 10, 1993, and Puerto Rico's Anti- Degradation Policy Implementation Procedure established in PRWQS. CWA Sec. 402(o)(2)(B)(i) allows backsliding if information is available which was not available at the time of permit issuance and would have justified a less stringent effluent limitation at the time of permit issuance. EPA has determined that it is appropriate to relax the effluent limitation for these parameters without violating anti-backsliding provisions of the CWA, in accordance with section 402(o)(2), since one of the exceptions to the provisions has been satisfied; and section 402(o)(3) since it complies with DNER's WQS which include antidegradation requirements. The DNER WQC constitutes a determination that the limit is sufficient to assure that the water quality standards are or will be attained. • Existing effluent limitation for Sulfates have been removed based on CWA section 402(o)(2)(B)(i). CWA section 402(o)(2)(B)(i) authorizes the backsliding of effluent limitations if information is available which was not available at the time of permit issuance that would have justified the application of a less stringent effluent limitation at the time of permit issuance. Based on review of effluent data since issuance of the existing permit, the modified discharge does not show a reasonable potential for the exceedance of water quality criteria for these parameters. • The water quality-based effluent limitation from the previous permit for Temperature, has been replaced with a more stringent water quality-based limitation in the Intent to Issue a WQC issued by the DNER. Pursuant to Section 401 (d) of the Act and 40 C.F.R. 122.44 (d) and 124.55, all State certified limitations and requirements contained in a Section 401 certification must be incorporated into a NPDES permit issued by EPA. The water quality-based effluent limitations referenced in this paragraph have been included in the draft NPDES permit, based on DNER's Intent to Issue a Water Quality Certificate. PART II. RATIONALE FOR STANDARD AND SPECIAL CONDITIONS A. Standard Conditions In accordance with 40 CFR 122.41, standard conditions that apply to all NPDES permits have been incorporated by reference in Part IV.A.1 of the permit and expressly in Attachment B of the permit. The Permittee must comply with all standard conditions and with those additional conditions that are applicable to specified categories of permits under 40 CFR 122.42 and specified in Part IV.A.2 of the Permit. B. Special Conditions In accordance with 40 CFR 122.42 and other regulations cited below, special conditions have been incorporated into the permit. This section addresses the justification for special studies, additional monitoring requirements, Best Management Practices, Compliance Schedules, and/or special provisions for POTWs as needed. The special conditions for this facility are as follows: NPDES Fact Sheet 6 ------- Puerto Rico Aqueduct and Sewer Authority NPDES NO. PR0022616 Enrique Ortega WTP 1. Special Conditions from the Water Quality Certificate In accordance with 40 CFR 124.55, EPA has established Special Conditions from the WQC in the permit that DNER determined were necessary to meet PRWQSR. The Special Conditions established in this section are only those conditions from the WQC that have not been established in other parts of the permit. 2. Best Management Practices (BMP) Plan In accordance with 40 CFR 122.2 and 122.44(k), BMPs are schedules of activities, prohibitions of practices, maintenance procedures, and other management practices to prevent or reduce the pollution to waters of the United States. The Permittee is required to develop a BMP Plan in Part IV.B.3.a of the permit to control or abate the discharge of pollutants. 3. Compliance Schedules A compliance schedule has not been authorized for any pollutant or parameter in the permit on the basis of 40 CFR 122.47. PART III. COMPLIANCE WITH APPLICABLE PROVISIONS OF OTHER FEDERAL LAWS OR EXECUTIVE ORDERS A. Coastal Zone Management Act - Under 40 CFR 122.49(d), and in accordance with the Coastal Zone Management Act of 1972, as amended, 16 United States Code (U.S.C.) 1451 etseq. section 307(c) of the act and its implementing regulations (15 CFR Part 930), EPA may not issue an NPDES permit that affects land or water use in the coastal zone until the Permittee certifies that the proposed activity complies with the Coastal Zone Management Program in Puerto Rico, and that the discharge is certified by the Commonwealth of Puerto Rico to be consistent with the Commonwealth's Coastal Zone Management Program. The Permittee has indicated the outfall is not in a coastal area managed by the Commonwealth's Coastal Zone Management Program and, although nearby, EPA has determined it will not affect the coastal area. Therefore, the requirements of 40 CFR 122.49(d) do not apply to this discharge. B. Endangered Species Act Under 40 CFR 122.49(c), EPA is required pursuant to section 7 of the Endangered Species Act (ESA), 16 U.S.C. 1531 etseq. and its implementing regulations (50 CFR Part 402) to ensure, in consultation with the National Marine Fisheries Service (NMFS) and U.S. Fish and Wildlife Service (USFWS) that the discharge authorized by the permit is not likely to jeopardize the continued existence of any endangered or threatened species or adversely affect its critical habitat. On April 16, 2009, EPA designated PRASA (a non-Federal representative) to conduct informal consultations or prepare a biological assessment for Section 7 Consultations, according to 50 CFR 402.8. In the past, no federally listed endangered or threatened species, or critical habitat, are in the vicinity of the discharge. Therefore, it has been determined that the discharge is not likely to affect species or habitat listed under the ESA. C. Environmental Justice - Not Applicable D. Coral Reef Protection - Not Applicable E. Climate Change EPA has considered climate change when developing the conditions of the permit. This is in accordance with the draft National Water Program 2012 Strategy: Response to Climate Change that identifies ways to address climate change impacts by NPDES permitting authorities (77 Federal Register 63, April 2, 2012, 19661-19662). Climate change is expected to affect surface waters in several ways, affecting both human health and ecological endpoints. As outlined in the draft National Water Program 2012 Strategy, EPA is committed to protecting surface water, drinking water, and ground water quality, and diminishing the risks of climate change to human health and the environment, through a variety of adaptation and mitigation strategies. These strategies include encouraging communities and NPDES permitting authorities to incorporate climate change strategies into their water quality planning, encouraging green infrastructure and recommending that water quality authorities consider climate NPDES Fact Sheet 7 ------- Puerto Rico Aqueduct and Sewer Authority NPDES NO. PR0022616 Enrique Ortega WTP change impacts when developing water load and load allocations for new TMDLs, identifying and protecting designated uses at risk from climate change impacts. The 2010 NPDES Permit Writers' Manual also identifies climate change considerations for establishing low-flow conditions that account for possible climatic changes to stream flow. The conditions established in the permit are consistent with the draft National Water Program 2012 Strategy. F. National Historic Preservation Act Under 40 CFR 122.49(b), EPA is required to assess the impact of the discharge authorized by the permit on any properties listed or eligible for listing in the National Register of Historic Places (NRHP) and mitigate any adverse effects when necessary in accordance with the National Historic Preservation Act, 16 U.S.C. 470 et seq. EPA's analysis indicates that no soil disturbing or construction-related activities are being authorized by approval of this permit; accordingly, adverse effects to resources on or eligible for inclusion in the NHRP are not anticipated as part of this permitted action. G. Magnuson-Stevens Fishery Conservation and Management Act - NOT APPLICABLE PART IV. PUBLIC PARTICIPATION The procedures for reaching a final decision on the draft permit are set forth in 40 CFR Part 124 and are described in the public notice for the draft permit, which is published which is published on EPA's website at https://www.epa.gov/npdes-permits/puerto-rico-npdes-permits. Included in the public notice are requirements for the submission of comments by a specified date, procedures for requesting a hearing and the nature of the hearing, and other procedures for participation in the final agency decision. EPA will consider and respond in writing to all significant comments received during the public comment period in reaching a final decision on the draft permit. Requests for information or questions regarding the draft permit should be directed to Carlos Rivera EPA Region 2, Caribbean Environmental Protection Division Permit Writer Phone: 787-977-5846 Permit Writer Email: rivera.carlos@epa.gov NPDES Fact Sheet ------- Puerto Rico Aqueduct and Sewer Authority NPDES NO. PR0022616 Enrique Ortega ATTACHMENT A — FACILITY MAP AND FLOW SCHEMATIC The facility map and flow schematic are attached as provided by the discharger in the application. NPDES Fact Sheet ------- Enrique Ortega WTP Flow Diagram Co-ag Bak jlatjion in: Coagulation Basins Distribution Chamber Coagulation Basins r".-• Potable Water Control Building Rapid Mixer I-' ¦ ' Filters (8) Filters (6) .. ¦- Wash Water Tanks /* \ 1 Mo.1 ' /-nVV / No.2 v_ ^6 EffUcnl OMR. Oil* P«kxl From 12/2CH61c 03/2021 Rc«w MGD Daily MWL f/HB. 5a,1 io mi Mm. 1.904 Raw Water From La Plata River 85 MGD To Municipal Landfill Penrlitled t1uv« teied on CQE'i apj*ttved STS Lajjatily. ------- |