Risk Management Through Water Efficiency Auditing A. Todd Lusk, PE - - PowerPoint PPT Presentation
Environmental Federation of Oklahoma October 30, 2014 Risk Management Through Water Efficiency Auditing A. Todd Lusk, PE ENVIRON International Corporation Florence, KY Presentation Topics You Cannot Manage What You Cannot Measure
Environmental Federation of Oklahoma October 30, 2014
ENVIRON International Corporation Florence, KY
2
Presentation Topics
Understanding Water Quality and Quantity
Water Audit
and Secondary Impacts for Water Reduction Opportunities
3
Integrated Water Management
Efficient Use
0.0 0.2 0.4 0.6 0.8 1.0 Baseline Residual
Green Water Green Water Blue Water Blue Water Grey Water Grey Water
Footprinting Watershed Management
Risk Mapping
4
Water Risk Drivers
5
Recognizing and Determining “Quality”
– pH – Conductivity/TDS/Salt – TSS
chemistry
– Organics – Metals
recycle technologies
– Cations/anions – Scaling potential – Silt Density Index
6
The “Four Rs” and Beyond
Treated Wastewater Discharge Reuse Treatment
Manufacturing
Water Source
REPLENISH REUSE RECYCLE REDUCE
Wastewater Treatment Manufacturing Wastewater Treatment
7
Expanding Water Stewardship
Life Cycle (Supply Chain + Producer + Consumer) Watershed Community Plant
8
The Water (Audit) Cycle
Green Water Blue Water Grey Water 0.0 0.2 0.4 0.6 0.8 1.0 BaselineBenchmarking & Baseline Footprint “Reasonable Reductions” in Use Water Efficiency Assessments “Reasonable Investments” Minimize Impact and/or Offset Residual Footprint Water Risk Reduction Strategy Residual Footprint
Green Water Blue Water Grey Water Green Water Blue Water Grey Water 0.0 0.2 0.4 0.6 0.8 1.0 Baseline Residual 9
Pre-Audit Investigations
– Balance known water intakes, uses, and outputs – Chronological trending – Usage and costs (current + projected)
10
Comprehensive Audit
– Review Facility Operations and Water & Salt Balances – Identify Opportunities for Flow/Cost Reduction – Rank Opportunities Based on Expected Payback Period
– Cooling/Utility Water Sources – Water Monitoring & Minimization – “Clean/Dirty” Stream Segregation – Steam/Condensate Management – Treatment/Reuse
– Water Savings vs. Economic/Multimedia Impacts – Flow Reduction vs. Effluent Quality
11
Simple Questions
– Do I have enough data to determine quality?
– Does it vary? If so, why?
– Apply the 4 Rs – Compare quality to other streams
12
Ranking Reduction Opportunities
implementation)
engineering, and plant impact)
– Rating 5 typically dependent on others, thus considered separately
13
Ranking Reduction Opportunities
Opportunity Overall Rating Water Savings (kgal/yr) % of 2013 Usage (%) Implementation Cost ($) Net Savings ($/yr) Payback (yrs)
14
Reduction Opportunities - Behavioral
Category Examples of Water Reduction Housekeeping § Reducing wash down flow, volume or frequency (e.g., high-pressure hoses, flow restrictors, dry cleanup procedures) Maintenance § Leak inspection and repair § Maintenance of flow measurement devices § Maintenance of flow delivery devices (shower heads, spray nozzles, hoses) Training § Develop tools to identify critical flow balance items § Establish employee awareness of reduction plans § Solicit employee suggestions/participation § Train the trainer approach § Standardized toolkit
15
Reduction Opportunities - Process
Category Examples of Water Reduction Metering
§ Install meters and recorders at key flow locations (intakes,
§ Develop estimating tools for unmeasured flows (e.g., cooling tower evaporation, product loss) § Maintain flow balance as operational tool
Quality Constraints
§ Establish quality criteria for indirect uses (e.g., cooling towers) § Reduce intake/blowdown rates to minimize fresh water usage in above processes (i.e., longer cycle times) § Introduce water treatment chemicals to improve cycle time § Set pump cooling/flushing water to minimum requirement per manufacturer recommendations
Process Controls
§ Review process control variables to identify less flow-intensive controls (e.g., pH or conductivity instead of time, timer instead of operator visual check) § Determine if changes to production scheduling could impact water balance § Automatic controls (e.g. solenoids) on product washing and conveyors to stop flow when production halts
16
Reduction Opportunities - Facility Upgrades
Category Examples of Water Reduction Low-flow and No- flow Processes § Replace water-based product cleaning with air systems § Replace water-based lubrication systems with dry lube (e.g., silicon-based) systems Water Reuse § Return “clean” streams into makeup for “less clean” streams with less stringent quality criteria Water Treatment § Plant-wide or process-specific water treatment (ultrafiltration and/or reverse osmosis) for recycle § Recovery and treatment of inflow reject streams (e.g., RO reject, filter backwashes) for in-plant use § Minimize backwash water volumes (proper chemical dosing, backwash on ∆P rather than schedule)
17
Cost-Benefit Analysis
Increasing Cost (Logarithmic) Increasing Water Reduction (Linear)
18
Indirect Benefits
– Increased throughput, lower unit cost
– Local, regional, national
– Audit findings at one site applicable to others
19
Trading Quantity for Quality
impacts effluent quality
– Residual organics (BOD, TOC) – TDS (salt) – Heavy metals – Suspended solids – Temperature
pretreatment may be needed
existing treatment
– Chemical usage – Biological treatment toxicity – Whole effluent toxicity
Increased Recycle Effluent Quality
20
In-Plant Impacts of Water Reduction
alkalinity
– Corrosion – Scaling
TDS/chloride
– Corrosion
pretreatment steps
– Neutralization – Softening
– HDPE/PVC vs. Cu/steel
21
Trans-Media Impacts
Concept Water Recycle/Reuse Project Solid Waste NOx Coal CO2 SOx Hg Power
22
A “Water-Energy Nexus”
Increasing Energy Demand
23
Closing Thought
When the well is dry, we know the worth of water.
Benjamin Franklin, Poor Richard’s Almanac