Important considerations for DPR 1. Consistent with current regulations in Florida 5. DPR lacks an environmental barrier 6. Multiple barrier approach (drinking water concept) to 2. Terms and definitions control pathogens and chemicals 3. Regulations or 7. Technical, operational, and managerial barriers permitting or guidance 4. Regulatory flexibility 8. Protective of public health (alternatives provision)
1.2 Build on current regulations in Florida • Florida IPR regulations – 62-610 Part V (F.A.C.) • Two levels of treatment (62-610.563) • Principal Treatment and Disinfection • Full Treatment and Disinfection • Discharge to Class I Surface Water (62-610.554) • Discharge to Other Surface Waters (62-610.555) • Groundwater Recharge by Injection (62-610.560) • Salinity Barrier Systems (62.510.562)
• Definitions – 62-610.200 (27) “Indirect potable reuse” means, for purposes of this chapter, the planned discharge of reclaimed water to surface waters to augment the supply of water available for drinking water and other uses. Indirect potable reuse is contrasted with “direct potable reuse” which involves the discharge of reclaimed water directly into a drinking water treatment facility or into a drinking water distribution system. • Engineering Report – 62-610.310 (1) In accordance with the requirements and provisions of Chapters 62- 600 and 62-620, F.A.C., an engineering report shall be submitted in support of permit applications for new or expanded reuse or land application projects. The engineering report will serve as the preliminary design report for reuse and land application projects.
Full Treatment and Disinfection (62-610.563) • Meet Primary Drinking Water Standards (MCLs) • Multiple barriers for • Organic compounds • Pathogens • Secondary Drinking Water Standards • TOC = 3 mg/L • TOX = 0.2 mg/L
Full Treatment and Disinfection (62-610.563) • Multiple barriers for “ Organic compounds ” and Pathogens • “The treatment processes shall include processes which serve as multiple barriers for control of organic compounds and pathogens.” • Secondary Drinking Water Standards • Is TDS of 500 mg/L an issue? • TOC = 3 mg/L • Is this needed? • TOX = 0.2 mg/L • Needed? “Additional reductions of pollutants which otherwise would be discharged in • quantities which would reasonably be anticipated to pose risk to public health because of acute or chronic toxicity shall be required .” (62 -610.560c3)
Other 62-610 Part V requirements • Pilot testing (62-610.564) • “Pilot testing is required for all projects that are required to provide full treatment and disinfection” • Require? • Reliability and staffing (62-610.567) • Monitoring (62-610.412) • Operating protocols (62-610.310, 62-610.568, and 62-610.613) • General Technical Guidance, Related Rules, and Forms (62-610.300)
1.3 Terminology • Certain terms must be defined in regulations • Many terms that may be best addressed in policy, guidance, and/or permitting, which allows for flexibility • Terms used for outreach and communication purposes • Purified water • Trend towards using just “potable reuse” for both IPR and DPR • California legislation specifies terms for DPR: • “Raw water augmentation” • “Treated drinking water augmentation”
1.4 Public Outreach Is “public attitude” the biggest challenge to potable reuse?
Psychology of Water Reuse Human Reactions to Water Reuse (WateReuse Foundation 2004) − Workshop with psychologists ▪ “Law of Contagion” – Once in contact always in contact ▪ Not fully subject to logic and science − Address through “framing” ▪ Process to categorize and ignore parts of reality ▪ Frame things out of awareness ▪ Not think about where something has been (restaurant forks and plates)
Use Advanced Treated Recycled Water as an Addition to Drinking Water Supply 45% 45% 40% 37% 36% 35% 35% 33% 30% 25% 2004 19% 20% 2011 16% 2012 15% 12% 12% 11% 11% 10% 10% 9% 10% 4% 5% 0% Strongly Somewhat Somewhat Stongly Unsure 48 Favor Favor Oppose Oppose
Public Tours of Facilities Help Educate the Consumer
Public Outreach: Key Activities Outreach Activity Purpose Provide a rationale for the need for Raise public confidence of the benefits and value of the DPR DPR project to the community. Identify public perception Use to assist in the development of strategies to alleviate these challenges to the DPR project concerns and improve public perception. Provide strategies to communicate about the DPR project to the Develop a DPR Communication Plan public, elected officials, and others, with the goal of building public confidence in and support of the DPR project. Develop and disseminate Provide objective, accurate, and timely information to raise communications materials on the awareness of the DPR project and address public concerns. DPR project Connect with outreach staff at other Gain practical information and lessons learned from the real- AWTFs world experiences of other potable reuse public outreach efforts. Engage industrial and commercial dischargers, as well as the Prepare a participation program for public, on means to eliminate or control the discharge of source control constituents into wastewater that can impact the production of ATW.
Regulation Permit Guidance 1.4. Outreach • What ? Outreach programs are strategic, transparent, and thorough. • Why? Public confidence and support is critical to the implementation of potable reuse projects. • Specific recommendations: • Not the role of regulators. • Start early. Continue throughout project. Terminology is important. • Use proven techniques. Develop consistent messages. • Use of a communications plan. Prepare for tough questions. • Build relationships.
1.5 DPR and Environmental Buffer No environmental buffer Drinking The Surface Advanced Wastewater water water water Gap treatment distribution treatment treatment system Maintain functionally of environmental buffer: • Additional treatment • Additional monitoring requirements • Additional “engineered” storage
1.6 Blending • Really talking about “dilution” • Require dilution of the advanced treated water? • Or limit the amount of advanced treatment water? • Big Spring, TX – limits advanced treated water to no more than 50% of water to the water treatment plant • Alternative: • Require a back up source of water if DPR facility is down or there is off-spec water
1.7 Multiple Barriers • Drinking water concept • Multiple treatment barriers for pathogens and chemicals • Increases resiliency of treatment • 62-610.563 FAC: • “The treatment processes shall include processes which serve as multiple barriers for control of organic compounds and pathogens .” • Define in regulations? With approach in guidance?
2. Technical Topics Review topics including water quality, treatment, and enginieering concepts that relate to the safety and production of potable reuse.
2. Technical Topics 2.1 Applications (Types of DPR) 2.2 Public health protection (pathogen and chemical control) 2.3 Source control 2.4 Wastewater treatment 2.5 Advanced water treatment 2.6 Treatment performance 2.7 Monitoring and instrumentation 2.8 Residuals management (including concentrate) 2.9 Facility operation (O&M) 2.10 Blending 2.11 Drinking water treatment
2.1. Potable Reuse Applications Groundwater Replenishment Spreading Injection Surface Water Augmentation Reservoirs, lakes, and water conveyance structures. Direct Potable Reuse With a surface water treatment plant Direct into a drinking water distribution system
Direct potable reuse (first type) producing advanced treated water Drinking Surface Advanced Wastewater water water water treatment distribution treatment treatment system
Direct potable reuse (second type) producing finished drinking water DPR facility: Drinking Advanced water treatment Wastewater water that meets SDWA treatment distribution requirements for Surface system Water Treatment Plant
Regulation Permit Guidance 2.1 Potable reuse applications Direct Potable Reuse • With a surface water treatment plant (produces advanced treated water) • Without a surface water treatment plant (produces finished drinking water)
2.2. Source Control Program Program to reduce chemicals in the wastewater collection system that impact treatment and/or final water quality Source control programs are essential for DPR Build on Federal Pretreatment programs Working with dischargers and residents (voluntary) Realistic expectations are needed Not possible to eliminate all hazardous chemicals Additional Benefit: Component of public outreach 61
Source Control Program Modify the pretreatment program so it is suitable for DPR Identify constituents in wastewater that may be very hazardous, difficult to remove, or are precursors to disinfection byproduct formation Inventory the sources and concentrations of selected constituents Include commercial and industrial entities Develop a program to inform consumers of best practices for home waste disposal
Regulation Permit Guidance 2.2 Source control • What ? Control of the discharge of constituents (chemicals) into a wastewater collection system that: 1. Can impact wastewater treatment. 2. Are difficult to treat. 3. May impair the water quality entering an advanced treatment facility. • Why? Beneficial, efficient, and cost effective strategy for managing chemicals by keeping them out of the wastewater system. • Specific recommendations: Understand the sewershed and sources of chemicals. • • Minimize discharge of harmful or difficult to treat chemicals. Improve wastewater water quality. Provide public with confidence. •
̶ ̶ ̶ ̶ ̶ 2.3 Potable Reuse Water Quality and Human Health Risks Microbial risk (mostly acute) Virus Protozoa Pathogenic Bacteria Chemical risk (mostly chronic) NDMA Natural and synthetic compounds Regulated and Unregulated Microbial and chemical risks exist with both conventional drinking water and potable reuse sources but differ in degree of source vulnerability
Regulation Permit Guidance 2.3 Public health protection What? Demonstrate public health protection through appropriate pathogen and chemical control based on treatment technologies, treatment performance, and monitoring. Why? Potable reuse involves a highly impaired source – wastewater. Regulators require that a certain level of risk protection is achieved and the public will need confidence. Specific recommendations: • Pathogen control (viruses, protozoa, and bacteria) • Chemical control (regulated and unregulated) • Treatment technologies and monitoring (indicators and surrogates)
Regulation Permit Guidance Microbial control • What ? For DPR, public health protection requires that pathogens in wastewater be removed or inactivated. • Why? Pathogens in recycled water include bacteria, viruses, and protozoan parasites. Pathogenic microorganisms present significant acute risks to the consumer and are the most important design and operating concern for DPR systems. • Specific recommendations: An appropriate goal is 1 in 10,000 annual risk of infection. • • A log removal target approach (including a log removal credit system) is needed since it is not possible to measure directly.
Log Removal • Log reduction relates to the percentage of pathogens physically removed or inactivated by a treatment process Under SDWA, treatment for surface water requires a 3-log removal for Giardia • and 4-log removal for viruses. 1-log reduction = 90% removal and/or inactivation • 2-log reduction = 99% • • 3-log reduction = 99.9% 4-log reduction = 99.99% • • 5-log reduction = 99.999% 10-log reduction = 99.99999999% • 12-log reduction = 99.9999999999% •
Regulation Permit Guidance Log Removal Targets • Comply with the following minimum log removals (including SWTR credits for the drinking water plant) starting from the raw wastewater (California): • 12-log reduction of enteric virus, • 10-log reduction of Giardia cysts, and • 10-log reduction of Cryptosporidium oocysts • Log removals can be adjusted based on an approved pathogen removal study of the wastewater treatment plant that assigns conservative log reduction credits (Texas) • Apply credits to wastewater facility, advanced water treatment facility, and drinking water facility based on regulatory review.
Regulation Permit Guidance Log Removal Credits • CA has assigned maximum credits at unit processes at IPR projects. • Specific unit processes with LRVs are (V/C/G): • Wastewater (2/1/1) • Microfiltration/ultrafiltration (0/4/4) • Reserve osmosis (1.5/1.5/1.5) • Advanced oxidation process (6/6/6) • Chlorination (6/3/0) • Process monitoring is needed for verification.
DPR Log 10 -Reduction Values (WRRF 11-02)
Example Pathogen Log Reduction Credits (Tchobanoglous et al., 2015) Log Reduction Credits Process Monitoring Notes V G C Secondary Study needed 0 - 1.9 0 - 0.8 0 - 1.2 “0” is the default. treatment Pressure decay test (PDT) should be done daily to MF or UF Daily PDT 0 4.0 4.0 verify proper performance. Electrical conductivity (EC) should be monitored in RO Online EC 1.5 1.5 1.5 RO influent and effluent. Log reduction in system control must be based upon measured values. Intensity UV sensors should be calibrated per U.S. EPA UV-AOP 6 6 6 sensors (2006). ESB with free System control is based on maintaining a minimum Online Cl 2 6 3 0 chlorine, CL 2 , free residual of 0.4 mg/L. Total 13.5 14.5 11.5
Altamonte Springs FL – DPR Pilot Filename.ppt/72
3 1 2 Pilot Secondary Filtered Effluent Ozone Biofiltration (Xylem) (Xylem) 6 3 4 5 GAC Filtration UV AOP (Calgon) Ultrafiltration (Trojan) (Toray/BiWater) Filename.ppt/73 Sample Point
Pathogen Log Reduction Credits for a Ozone-BAF Based Treatment Train for Direct Potable Reuse Unit Process Virus Giardia Crypto Ozone 5-log - - BAF + + + Ultrafiltration (UF) + 4-log 4-log Granular Activated Carbon - - - (GAC) UV AOP 6-log 6-log 6-log Engineered Storage with 4-log 3-log - Chlorine Total 15-log 13-log 10-log “+” indicates some removal expected “ - “ indicates no removal anticipated
CECs, PPCPs, PFCs are Removed Through the Pilot Antibiotic: Treats/prevents infections
CECs, PPCPs, PFCs are Removed Through the Pilot O₃+BAF
Regulation Permit Guidance Chemical Control • What ? Chemicals in wastewater must be removed to appropriate levels. • Why? Chemicals in recycled water include both regulated and unregulated chemicals. Chemicals are typically chronic (nitrate is a notable exception). Trace organics (e.g., CECs) are often discussed. • Specific recommendations: Meet all MCLs and any additional state requirements (regulated chemicals) • Meet relevant health criteria established for unregulated chemicals. • Monitor for surrogates and indicators of treatment (performance monitoring) • and water quality (verification monitoring). • Possibly use TOC as a measure for unknown chemicals.
Total Organic Carbon Concentration In Product Water Meets Florida IPR Regulations
Regulation Permit Guidance Chemical Control A tiered approach for chemical criteria based on the type of monitoring: • Tier 1: Regulated chemical constituents, including DBPs • MCLs, other state requirements • Tier 2: Unregulated chemical constituents with public health interest • Including CECs based on public health • Tier 3: Unregulated chemical constituents that provide information on the effectiveness of treatment • Including CECs • Detected frequently and at sufficient concentrations to make them useful measures of the removal of health-significant organic chemicals
Regulation Permit Guidance Chemical Control - Salinity • What ? TDS and individual constituents. • Why? Salinity is not a public health issue, but salinity must be managed to maintain acceptable aesthetics and for recycled water quality. Individual constituents (chloride, bromide, etc) are also important. • Specific recommendations: Salinity is often a regional issue. • • Include salinity as a consideration in planning and design. Understand the long-term changes in salinity. • • Removing salinity requires advanced treatments such as RO.
2.4 Wastewater Treatment Differences between different secondary treatment • processes. Issues related to the use of conventional wastewater • treatment in potable reuse applications. Benefits of using a higher quality efflue1.1 DPR • background information
5 Steps in the Wastewater Treatment Process
Regulation Permit Guidance Wastewater treatment • What ? Provide a consistent, high-quality effluent. • Why? As a source water for DPR, WWTPs should produce an effluent optimized for further processing by Advanced Water Treatment Plant. • Specific recommendations: Source control • • Minimum treatment requirement Assignment of log removal credits • There are benefits with using a higher quality effluent in a potable reuse • treatment train. As a result, enhancements should be considered.
Regulation Permit Guidance Wastewater optimization Possible measures to improve performance and enhance reliability: Enhanced screening process and, possibly, fine screening. • Influent flow and load equalization. • • Elimination (or equalization) of untreated return flows. Operational mode for biological treatment process to improve reliability and • produce an effluent of consistent quality. Improved disinfection while preventing DBP formation. • Post-treatment filtration (remove suspended solids). • • Improved online and offline process monitoring.
Regulation Permit Guidance 2.5 Advanced water treatment (AWT) • What ? Involves unit processes (a range exists) for treating wastewater effluent to produce a drinking water source of supply. • Why? Must meet regulatory review (pathogens and chemicals) and public scrutiny. • Specific recommendations: Define the objectives (pathogen log removals and chemical control). • Do not list specific treatment trains (avoid the notion of prescribed trains). • • Instead, provide lists of advanced treatments and the capabilities. Use of pilot testing and/or demonstration studies. • Final water quality will vary based on the treatments employed. • Track research and field experience. Understand reliability (performance of • treatment).
Example DPR treatment trains From the draft Expert Panel Report on the Feasibility of Developing DPR Criteria for Calif. (2016)
Removal of Chemicals through DPR Processes (RO) RO + UV Achieves Removal of CECs 100,000 RWPF Influent RO Feed 10,000 AOP Feed Product Water 1,000 ng/L 100 10 1 0 Reuse-14-12 Enhanced Pathogen and Pollutant Monitoring at Big Spring, TX (Eva Steinle-Darling, Carollo)
Alternative Approaches for Potable Reuse Full Advanced Treatment MF RO UV/H 2 O 2 Alternative based on O 3 -BAC MF O 3 BAC UV Advantages of O 3 -BAC Disadvantages of O 3 -BAC Excellent CEC removal Disinfection byproducts Eliminates RO concentrate No TDS reduction Reduces capital and O&M costs Higher product water TOC 88 Source: Trussell Technologies
Differences in Effluent Quality Between Advanced Water Treatment Processes
Regulation Permit Guidance 2.6 Treatment performance • What ? Process control and monitoring • Why? Document system performance and monitor chemical and pathogen reduction or measure specific criteria. • Specific recommendations: Automated system control • • Start-up performance Performance monitoring (long-term monitoring; surrogate and indicator monitoring) • • Frequency, locations, regulatory vs. process, online vs. periodic Use of Critical Control Points •
Regulation Permit Guidance 2.7 Long-term monitoring • What ? Performance monitoring. • Why? Demonstrate continuous production of high-quality water protection of public health. • Specific recommendations: Online where possible. • Rapid surrogate measures. • • Assure log-removal targets are met. Develop periodic sampling requirements. • Use of alarms, shutdowns, and flow diversions. •
Performance Monitoring: Example Online and Calibration Sampling (Tchobanoglous et al., 2015) Process Test Type and Frequency of Sampling Turbidity: online (continuous) and grab Turbidity and microbial indicators (weekly); microbial: grab (weekly) Secondary effluent Ammonia, TSS, and BOD Grab (weekly) PDT Offline testing (daily) MF or UF Turbidity Online (continuous) and grab (weekly) RO Influent and effluent EC and TOC Online (continuous) and grab (weekly) Online (continuous) and verification UV sensors (weekly) UV-AOP Influent UVT Online (continuous) and grab (weekly) Influent and effluent chloramine Online (continuous) and grab (weekly) ESB with free Effluent free chlorine residual Online (continuous) and grab (weekly) chlorination
Treatment Reliability – Critical Control Points Critical Control Points in Reverse Osmosis CCPs are points in the (Reuse-13-03) treatment process that are NDMA Control specifically designed to Acid/Antiscalant Chloramine Microorganisms & Chemicals of Concern reduce, prevent, or eliminate a human Wastewater Reverse Osmosis Strainer Microfiltration Treatment Plant Microorganisms health hazard and for which controls exist to ensure the proper performance of that H 2 O 2 UV Chlorine Engineered Storage Drinking Water Plant or Distribution process. Microorganisms & Microorganisms Chemicals of Concern Stabilization Lead/copper leaching in distribution system
Example: Control Control Points From the draft Expert Panel Report on the Feasibility of Developing DPR Criteria for Calif. (2016)
Regulation Permit Guidance Critical Control Points • What ? Point in the treatment train (i.e., a unit treatment process) that is designed to reduce, prevent, or eliminate a human health risk and for which controls exist to ensure the proper performance of that process. • Why? Systematic approach to inform the effective operation of AWTF through performance-based monitoring (augment end-of-pipe monitoring) • Specific recommendations: Steps: • Identify hazards • Identify CCPs • Identify monitoring procedures • • Identify corrective actions and procedures
Human Cell Line Bioassays • Used for years in pharmaceutical • Estrogen like chemicals field • Glucocorticoid/ progesterone • Measures “bioactivity” of a like chemicals chemical class • Androgen like chemicals • Ability to measure for “unknown” • Dioxin like chemicals chemicals • Genotoxicity • Ability to measure “mixtures” • Cytotoxicity • Use as a screening tool and for benchmarking
Bioassays Indicate Bioactivity of Hormones/Chemicals is Eliminated Through the Pilot Processes Estrogen like chemicals
2.8 RO Concentrate Issue for inland communities • If RO is used in the treatment train, the management of • RO concentrate is a major consideration. A number of RO concentrate disposal options are • available, though cost is a factor
Regulation Permit Guidance 2.9 Facility Operation • What ? Operation and maintenance (O&M) for DPR system to operate consistently and reliably. • Why? Appropriate O&M is needed to ensure that all public health objectives are met. • Specific recommendations: • Commissioning and initial start up Shutdown plan • O&M Plan (critical item) • Operator Training and Certification • Reporting •
Components of an O&M Plan for a DPR System (Tchobanoglous et al., 2015) Staffing (i.e., for daily operations and emergencies) Operator training and certification Checklists for operations procedures (daily, weekly, and monthly) Routine maintenance of equipment Critical spare parts and failure training Control system (e.g., SCADA, shutdown procedures, and alarms) Process monitoring and control Regulatory compliance Frequency of monitoring Distribution System Response time to treatment failures or non-compliant water quality
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