WATER IS WATER REGARDLESS OF SOURCE, WE MUST TREAT ALL WATER AS A CRITICAL RESOURCE
Centralized and Distributed Water Reuse Opportunities Presentation to USDOE Conference Las Vegas, NV Robert Rubin, Ed. D. Professor Emeritus, NCSU-BAE Raleigh, NC
Outline What is reclaimed or Non-Potable water? Why consider reuse? Reuse practices – current and future Centralized or distributed systems Reuse project examples First steps to evaluate / implement reuse Questions & answers / discussions
Reclaimed Water –Water derived from the treatment of Domestic, Municipal or Industrial wastewater that is a supplanted source suitable for and meeting standards for Beneficial Use Reuse –Beneficial use of reclaimed water. –Fit for purpose Reuse is Not Disposal – You are Producing and Recycling a Valuable Product! Water Reuse Terms
Broadened Definitions Needed Non-Potable Multiple sources –Treated wastewater –Treated stormwater –Harvested rainwater
Top Drivers for Reuse Replace demand for drinking water used for non-potable purposes Sustainable supply – drought proof – supply can grow with community Regulatory influence – NPDES Program – Permits, TMDLs, Non-Deg Right thing to do – sustainability or green objectives
Why Water Reuse? Limited New Water Sources Zero Discharge or Interbasin Transfer (IBT) Requirements Restores Groundwater / River / Lake Levels Sustainability Offers Reliable Clean Water Supply Potential Cost Savings to Users Reduces Pollutants to Rivers and Estuaries Social / Environmental Benefits Growth / Infrastructure Needs Major Investments
A Shift in Policy House Bill The Drought Bill
Basic Provisions of Recent NC Water Legislation Better management of water resources by state agencies and system owners Requires EMC to adopt rules for water conservation Requires EMC to adopt rules for water reuse Place more constraints on IBT Makes conservation provisions mandatory Streamlines drought management and water emergency powers of government Signals changes in water management policy in the State
DOE Sustainability Challenge High Performance Buildings –Metering Water Energy LEED – WETAG Onsite reuse important tool !!!
LEED Certification Leadership in Energy and Environmental Design
Water Reuse Challenges Public Perceptions Public Relations Public Outreach Inexpensive Water Supplies Cross-Connection Controls Cost of Treatment and Distribution Lack of Stakeholder Consensus End User Costs Retrofitting Costs Staff Costs Limited Regulatory Guidance Policy Makers Acceptance / Support Water Rights Minimum Stream Flow Requirements
Some Benefits of Reclaimed Water Systems Reduces the demand for potable water –Reduces demands on WTP operation Average flow Summer peak flow –Reduces demands on raw water sources Reduces the discharge from WWTPs –Reduces impact to surface waters –Reduces annual loading of pollutants (nutrients, metals, BOD, etc.) Reduces the need for inter-basin transfers Use of reclaimed water will not significantly affect surface water volumes
Current Reuse Practices
Use of Reclaimed Water - Irrigation Golf Courses, Residential Lawns, Agricultural Sites, Cemeteries, Parks, School Grounds, Commercial / Industrial Site Grounds, Landscape Areas, Roadways, Medians and Other Similar Areas
Other Uses of Reclaimed Water –Industrial purposes such as process or cooling water; –Aesthetic purposes such as decorative ponds or fountains, dust control, street cleaning and other similar uses –Bulk reuse programs
Other Uses of Reclaimed Water Fire Protection Urinal / Toilet Flushing Chillers / Cooling Pollution Abatement Commercial / Industrial Buildings, Hotels or Motels
Applications One DWRC project analyzed 20 case studies Locations in U.S. and Australia where decentralized systems are being used for wastewater service When to Consider Distributed Systems in an Urban and Suburban Context – er er
Future Reuse Opportunities
Irrigation of Food Chain Crops Principal Concern – Transmission of Pathogens Multibarrier Treatment / Disinfection –Tertiary quality effluent (biological treatment, filtration) –Membranes –Chlorination –Ozonation –Ultraviolet Light –Advanced Oxidation Procedures (AOPs)
Wetland Augmentation Natural wetlands – Hardwood and Pine Flats Degraded via clear-cut, ditching, drained, or managed Benefits such as wildlife habitat; passive and active recreation, boardwalks, bird watching, creature watching, public / schoolchildren education.
Stream Augmentation Streams Benefits such as enhancement of degraded biological habitat - 303d listed streams (WQ or Habitat); reclaimed water in streams that are subject to "drying up; loss of habitat – mussels, fish, etc., public parks, public education, water features.
ASRs & Groundwater Recharge ASRs – Opportunities to store hundreds of millions of gallons of water Coastal Barriers for Saltwater Intrusion Slow Rate / High Rate Infiltration Systems – Aquifer Recharge Statutory Restrictions, Geochemistry
Planned Direct and Indirect Potable Reuse Few National Examples Generally, no more than 25% direct feed for direct reuse (treatment plant to treatment plant / pipe to pipe) Indirect – natural buffers – surface or groundwater –Two to Twelve month travel time between infiltration / withdrawal –Minimum 2,000 foot between infiltration / withdrawal
Regulatory Incentives Resource Management – Legislative and Regulatory enhancements in progress Division of Water Resources – Water Supply Planning Stimulus Money - Green Project Funding Division of Water Quality – Wastewater Management
Future Trends More efficient use of our water resources Conservation Agricultural reuse for food & non-food crops Residential reuse Indoor reuse Planned direct & indirect potable reuse
Many Available Technologies Fixed media –May be effective for VERY small flows –MBBR –Moderate footprint Suspended media –Most effective with consistent flow –MBR –SBR –Small footprint
Advances in Treatment & Control Technologies
Microfiltration A Physical Barrier to Eliminate Pathogens Influenza Virus 0.1 micron Cryptosporidium Oocysts 3-8 micron Legionella Bacteria micron Pseudomona diminuta 0.28 micron
Create Multiple Barrier Process Organic Contaminants Biological Treatment Nutrient Removal BNR Anaerobic/Anoxic/Aerobic Colloidal Particulate Removal Microfiltration Membranes Pathogen Removal Biological Treatment Microfiltration Membranes UV Chlorine Residual AOP (O3)
The MBR Process Anoxic Zone Aerobic Zone Membrane Operating System Equipment Skid Rotating Drum Screen
Sequential Batch Reactors Tertiary Cloth-Disk Filtration Reclaimed Water Pumping Station Biological Treatment Tanks New 0.5 MGD Sequential Batch Reactor Wastewater Reclamation Facility in Oriental, NC
Satellite/Distributed/Decentralized Reclaimed Water Systems MBR or Conventional WRF 6 MGD Plus Solids Treatment MBR WRF 1 MGD MBR WRF 1 MGD MBR WRF 2 MGD As growth in reclaimed water demands increases, system can grow to accommodate demand
UseFecal Coliform Counts/100 ml BOD mg/lTSS mg/l TN mg/l Turbidity NTU High Risk – edible crop irrigation 2.2 (BDL) Moderate Risk NA10 High Risk – groundwater contact 2.2 (BDL)513<2 1. Where BDL is Below Detection Limit Typical Water Quality Standards Imposed on Reuse Programs (Check with local permit authority)
Recognition The USEPA recognizes onsite and decentralized wastewater systems as a permanent and essential element of the nations wastewater infrastructure… Onsite systems MUST be managed as an element of infrastructure… Partnerships Essential
Decentralized Program Strategy Vision: Decentralized wastewater systems are appropriately managed, perform effectively, and are widely acknowledged as components of our nations wastewater infrastructure. Mission: EPA will serve as a catalyst for improving system performance through partnering to upgrade professional standards of practice and institutionalize the concept of perpetual management.
Decentralized Approaches to Wastewater Treatment U.S. Environmental Protection Agency Office of Wastewater Management
Managed Infrastructure – Making Onsite Permanent Responsible Management Entity City, County or District Government Private Utility-State Utility Commission –NSU (Solaire, Battery Park)
Management Programs ProgramFeature Inventory/awarenessTraditional system, low risk environment ContractMechanical systems, low risk environment PerformancePerformance base, moderate risk environment RME OperationPerformance base, professional operation RME OwnershipPerformance base, professional operation, high risk
USEPA Management Elements Planning Performance Site Evaluation Design Construction O and M Residuals Certification/Licensing Education/Training Inspection/Monitoring Corrective Action Records/Reports Financial Assistance
Purpose of Management Elements Sustainability –Assurance that the centralized and decentralized systems are managed in perpetuity as a permanent and essential element of infrastructure
Management Permitted to management entity (not HOA) Utility fee determined by utility commission Certified operators required
Cooper, Robertson & Partners RTP – Existing / Projected Water Balance without Reuse Site Precipitation Potable Water Supply 3.25 MGD 22 MGD Evapotranspiration & Infiltration 1.13 MGD 10 MGD.25 MGD 12 MGD Cooling Tower Evaporation Irrigation Stormwater Runoff 1.87 MGD Sanitary Sewer Discharge Water Balance
Cooper, Robertson & Partners Reuse (Wastewater / Building Stormwater Capture) MGD RTP – Potential Water Balance Transformation with Reuse Site Precipitation Potable Water Supply 45-90% Reduction MGD 22 MGD Evapotranspiration & Infiltration 1.13 MGD 10 MGD.25 MGD 12 MGD Cooling Tower Evaporation Irrigation Stormwater Discharge 1.87 MGD Sanitary Sewer Discharge % Reduction Jordan Lake Reuse Project.4 MGD Water Balance
Steps to Evaluate / Implement Reuse I.Market Demands II.Reclaimed Water Demand Projections – Initial Planning Period (Planning Horizon of 25 Years) a.Irrigation Demands (Landscape, Lawns, Common Areas, etc…) b.Industrial Demands (Chiller / Cooling Water Makeup, Boiler Feed, Washdown, etc…) c.Indoor Demands (Toilet Flushing, Courtyards, Dual Plumbing, etc…) d.Fire Protection e.Other Uses (Aesthetics, Fountains, Ponds, etc.) f.Continuous vs. Seasonal Operations Average Daily Flows & Pressures Peak Daily Flows & Pressures Daily Demand Curves Demand Projection Curves
Steps to Evaluate / Implement Reuse II.Reclaimed Water Quality a.Effluent Treatment Requirements/Standards for Planned Uses III.Establish Infrastructure Needs a.Reclaimed Treatment Considerations / Alternatives b.Reclaimed Storage c.Reclaimed Distribution System IV.Preliminary Design of Reuse Infrastructure a.Treatment System(s) b.Nutrient Management Plans c.Storage & Distribution System Hydraulic Model Backflow Prevention and Cross Connection Control Program Standard Reuse System Details and Specifications d.Irrigation Systems e.Hydraulic and Nutrient Loading Considerations f.Industrial Systems g.Indoor Systems/dual distribution
Steps to Evaluate / Implement Reuse V.Capital Improvement Program a.Preliminary Project Cost Estimates i.Treatment Alternatives ii.Distribution System Alternatives iii.Storage b.Reclaimed User Systems c.Five Year Capital Improvement Program VI.Public Education / Outreach Needs a.Work Sessions with Community Leaders b.General Public (Staff / Students) Education / Outreach c.End-User Training and Education
Questions? Comments?
Water Reuse Opportunities Or 1800-ask-Ivan Bob Rubin, Ed. D., NCSU; Raleigh, NC