Proposed reclaimed water use for urinal and toilet flushing Regulation 84 Stakeholder Meeting August 17, 2017 Thank you for being here!
Welcome Brandi Honeycutt Lillian Gonzalez Environmental Protection Specialist Unit Manager Permits Section Permits Section Water Quality Control Division Water Quality Control Division CDPHE CDPHE
Welcome & Overview Lisa Beutler Executive Facilitator Stantec
Workshop Goals Provide stakeholders an overview of the proposed changes to Regulation 84 and regulatory process Receive input from participants on benefits, concerns, and additional considerations regarding this proposed use of recycled water
Workshop Agenda Items Welcome and Overview Opening Remarks Overview of key topics for discussion Topic 1: Proposed regulatory framework to protect public health 1. Expert Presentation: background on toilet flushing with graywater and recycled water 2. Overview of regulatory proposal 3. Discussion Topic 2: Implementation 1. Expert Presentation: managing opportunistic pathogens 2. Discussion Topic 3: To be determined by stakeholders Wrap up, closing comments, evaluation, adjourn
Ground “Rules” http://colowqforum.org/pdfs/code-of- conduct/CWQF%20Code%20of%20Conduct.pdf Come prepared for the scheduled discussion. Speak up so that everyone can hear. Only one person should speak at a time. Be concise. Avoid personal attacks. Be respectful of others’ perspectives and responsibilities. Sort for similarities that may exist in spite of differences. Listen carefully and respond in a manner that moves the discussion forward. Clearly identify remaining differences that are not resolved. Avoid sneak attacks. Respect the process by letting others know of positions and actions that will be taken regarding the issues being discussed. Decision making method: Consensus (everyone understands and can live with the decision), Fall back method: Minority report Avoid end runs. Respect the process by letting others know if differences remain that will be pursed in other venues (e.g. directly with other members in the executive and/or legislative branches of state or federal government. Identify conversations that aren’t working . Backtrack from poor results.
Opening Remarks Damian Higham Senior Planner Recycled Water Program Denver Water
Reclaimed Water Basics • Regulation 84 governs reclaimed water in Colorado • Source is wastewater that has been treated at a wastewater treatment plant for discharge to surface waters • Further treated by reclaimed water plant to meet specific water quality standards • Provided for non-potable uses • Delivered in separate purple pipe distribution system • 5.2 billion gallons of potable water saved with reuse 8 8/22/2017
Reclaimed Water Treatment • 3 categories of water quality designations • Uses tied to specific water quality categories • Standards for: – Turbidity/TSS as overall water quality indicator – E. coli as a pathogen indicator • Cat 2 max E. coli based off swim beach standards • Category 1 is secondary wastewater treatment and disinfection, Cat 2 & 3 add filtration 9 8/22/2017
Colorado Water Plan • “The CDPHE is committed to working with stakeholders to ensure that health and environment are protected while water reuse expands ” • 8 Actions specific to increasing reuse in Colorado – Increasing funding and incentives for water recycling and expanding the list of uses for which recycled water can be applied. 10 8/22/2017
Current major types of water Potential paradigm for water reuse practiced in Colorado reuse practice in Colorado Non-food crop Other non-food Cooling Cooling irrigation crop irrigation and other and other (seasonal) (seasonal) industrial industrial Landscape irrigation Landscape irrigation uses uses (seasonal) (seasonal) ? ? Livestock washdown and Food crop watering Toilet flushing irrigation (year round) (seasonal)
Toilet Flushing Drivers • Residential consumption comprised of ~25% toilet flushing • At Denver Water alone, 4.4 billion gallons used for flushing residential toilets • Commercial sites already exploring green options would have another use to put reclaimed water towards 12 8/22/2017
Premises 5. This newly permitted use would create additional water supply in a stressed 1. Promoting the system. use of reclaimed water while protecting public 7. This newly permitted use will health and the allow Colorado to environment is the join other states in this paramount goal of approach to reuse Reg 84. water efficiently. 3. Potable water may not be necessary for urinal and toilet flushing.
Overview Today’s discussion is divided into three topics: 1. Regulatory proposal 2. Implementation 3. TBD by workshop participants The presentation slides and workbook provide a starting point for discussion. Regulation Guidance Items that can be covered in Items that need to be codified supplemental guidance in regulation to protect public documentation health and the environment Notional example: Notional example: Prescriptions for specific Disinfection requirements language on safety signs
Context of Discussion Topics Some topics that are important considerations in implementation, but not within the scope of a potential change to Regulation 84 or supplemental guidance are “out of scope” for today’s workshop. Notional “In Scope” Example: Define a quality of water that is protective of human health Notional “Out of Scope” Example: Cost of installing dual-plumbing (potable and reclaimed water) inside a facility.
Exposure Pathways Dermal Reclaimed water Inhalation in toilets, urinals, Humans and premise Direct consumption plumbing (if a cross connection error occurs)
Industrial Industrial Pre-Treatment Wastewater Treatment Wastewater Pollutants of special concern (toxic Preliminary Primary Secondary Tertiary/Advanced Disinfection chemicals, metals, pesticides, etc.) Large materials Medium particles & Organic matter (compounds Some facilities go one step Kill pathogens (rags, plastic floating oils/grease that would drop oxygen further to reduce specific bags, rocks, etc.) levels in receiving river); pollutants (nitrogen, some removal of trace phosphorus, particles); chemical constituents and some removal of trace pathogens chemical constituents and pathogens Domestic Wastewater Wastewater Treated Wastewater Effluent Recycled Water Treatment Additional Treatment Disinfection Pollutants of special concern (particles, pathogens) are Kill pathogens removed by various treatment methods; some removal of trace chemical constituents, etc. is achieved Recycled Water Potable Water Conventional water treatment plant Other water sources
Questions for Consideration and Discussion: • What level of treatment should be required when using recycled water for toilet flushing? Topic 1 – Category 1, 2 or 3? • Disinfection – How much disinfection should be required? – Should a residual be required? Topic 2 • Are there best management practices that should be followed when using recycled water for toilet flushing? – Use of dye – Cross connection control inspections – Purple piping – Other best management practices ? 18 8/22/2017
Topic 1: Proposed regulatory framework to protect public health Damian Higham Senior Planner Recycled Water Program Dr. Sybil Sharvelle Denver Water Associate Professor Civil and Environmental Engineering Colorado State University
Background on Regulation 86 and WE&RF Framework for Decentralized Non-Potable Water Systems Sybil Sharvelle Colorado State University
Regulation 86 Irrigation Toilet Flushing Category A B C D Scale Single family, Non-single Single family Non-single Family family System Laundry to Storage with 60 NSF-350 NSF-350 Requirements Landscape or mesh filtration, Certified, Free Certified, Free Storage with BMPs Chlorine 0.2 – 4 Chlorine 0.2 – 4 60 mesh mg/L mg/L, PE filtration, designed BMPs
NSF 350 Class R a Class C b Parameter Single Sample Single Sample Test Average Test Average Maximum Maximum CBOD 5 (mg/l) 10 25 10 25 TSS (mg/l) 10 30 10 30 Turbidity (NTU) 5 10 2 5 E. coli (MPN/100 ml) 14 240 2.2 200 pH (SU) 6.0-9.0 6.0-9.0 Storage vessel residual chlorine ≥ 0.5 - ≥ 2.5 ≥ 0.5 - ≥ 2.5 (mg/l) a Class R: Flows through graywater system are less than 400gpd b Class C: Flows through graywater system are less than 1500gpd
Decentralized Non-potable Water (DNW) Systems • A system in which water from local sources is collected, treated, and used for non-potable applications at the building to district/neighborhood scale generally at a location close to the point of generation.
Differs from Existing Reclaimed Water Programs • Targets decentralized systems • Lower oversight • Rigorous design of treatment process train • Design to meet pathogen log reduction targets • Verification that log reduction targets are met • Continuous online monitoring for surrogate parameters • Real time process controls for out of specification
Quantitative Microbial Risk Assessment (QMRA) Characterize Exposure Select Set Log Pathogens (Based on Acceptable Reduction in Source End Use) Level of Risk Target Water
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