water is water regardless of source, we must treat all water as a critical resource
TRANSCRIPT
WATER IS WATER
REGARDLESS OF SOURCE, WE MUST TREAT ALL WATER AS A CRITICAL RESOURCE
Centralized and Distributed Water Reuse Opportunities
Presentation to USDOE ConferenceLas Vegas, NV
Robert Rubin, Ed. D.Professor Emeritus,
NCSU-BAERaleigh, 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
Reclaimed Water Quality Comparison
North Cary Reclaimed Water Program
Comparison of Water Quality Parameters
Parameter (mg/L, except where noted)
Drinking Water Standard
Cary/ Apex Tap Water
Jordan Lake Water
North Cary Reclaimed Water
Re
Iron 0.3 0.02 9 0.151 0.039
Manganese 0.05 0.012 0.277 0.018
Calcium n/a 8.48 not meas. 15.95
Magnesium n/a 2.20 not meas. 4.21
Sulfate 250 25.1 not meas. 48.7
Chloride 250 10.5 15.3 47.2
Dissolved Solids 500 75 n/a 207
Hardness n/a 30.25 33.1 57.16
pH 6.5 -8.5 7.2 6.9 6.8 -7.2
Turbidity (NTU) 0.5 0.29 3.97 0.36
Total Nitrogen n/a not meas. not meas. 2.08
Total Phosphorus n/a 0.05 0.03 0.043
Fecal Coliforms (#/100 ml) 0 0 333 0
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 NeedsMajor Investments
A Shift in PolicyHouse Bill 2499 - 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 CertificationLeadership 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 CostsRetrofitting CostsStaff 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 – www.werf.org/distributedwater
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 AugmentationNatural wetlands – Hardwood and Pine FlatsDegraded via clear-cut, ditching, drained, or managedBenefits such as wildlife habitat; passive and active
recreation, boardwalks, bird watching, creature watching, public / schoolchildren education.
Stream AugmentationStreams
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 ReuseFew 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
InfluenzaVirus 0.1 micron
CryptosporidiumOocysts3-8 micron
LegionellaBacteria0.6-1 micron
Pseudomona diminuta0.28 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 StationBiological Treatment Tanks
New 0.5 MGD Sequential Batch Reactor Wastewater Reclamation Facility in Oriental, NC
Satellite/Distributed/Decentralized Reclaimed Water Systems
MBR or Conventional WRF6 MGD
Plus Solids Treatment
MBR WRF1 MGD
MBR WRF1 MGD
MBR WRF2 MGD
As growth in reclaimedwater demands increases, system can grow to accommodate demand
Use Fecal ColiformCounts/100 ml
BOD mg/l TSS mg/l
TN mg/l
Turbidity NTU
High Risk – edible crop irrigation 2.2 (BDL)1
5-10 5-10 10 2-10
Moderate Risk
2.2-14 5-30 5-30 NA 10
High Risk – groundwater
contact 2.2 (BDL) 5 1 3 <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 ProgramsProgram Feature
Inventory/awareness Traditional system, low risk environment
Contract Mechanical systems, low risk environment
Performance Performance base, moderate risk environment
RME Operation Performance base, professional operation
RME Ownership Performance 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)
1-2.5 MGD
RTP – Potential Water Balance Transformation with Reuse
Site Precipitation
Potable Water Supply
45-90% Reduction
.35-1.85 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
55-100% Reduction
Jordan Lake Reuse Project
.4 MGD
Water Balance
Steps to Evaluate / Implement ReuseI. Market DemandsII. 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 Protectione. Other Uses (Aesthetics, Fountains, Ponds, etc.)f. Continuous vs. Seasonal Operations
Average Daily Flows & PressuresPeak Daily Flows & PressuresDaily Demand CurvesDemand Projection Curves
Steps to Evaluate / Implement ReuseII. Reclaimed Water Quality
a. Effluent Treatment Requirements/Standards for Planned UsesIII. Establish Infrastructure Needs
a. Reclaimed Treatment Considerations / Alternativesb. Reclaimed Storagec. Reclaimed Distribution System
IV. Preliminary Design of Reuse Infrastructurea. Treatment System(s)b. Nutrient Management Plansc. Storage & Distribution System
Hydraulic ModelBackflow Prevention and Cross Connection Control ProgramStandard Reuse System Details and Specifications
d. Irrigation Systemse. Hydraulic and Nutrient Loading Considerationsf. Industrial Systemsg. Indoor Systems/dual distribution
Steps to Evaluate / Implement ReuseV. Capital Improvement Program
a. Preliminary Project Cost Estimatesi. Treatment Alternativesii. Distribution System Alternativesiii. Storage
b. Reclaimed User Systemsc. Five Year Capital Improvement Program
VI. Public Education / Outreach Needsa. Work Sessions with Community Leadersb. General Public (Staff / Students) Education /
Outreachc. End-User Training and Education
Questions? Comments?
