environmental services business · pdf file• begins with flexible design ... purolite...
Post on 07-Mar-2018
222 Views
Preview:
TRANSCRIPT
Environmental Services Business Group
Reducing O&M Costs with Remedial Process Optimization: Concepts and Case Studies 2013 Alabama Department of Environmental Management Groundwater Conference - June 5, 2013, Mike Perlmutter, P.E.
2
Agenda
Overview of Remedial Process Optimization (RPO) Strategy for Site Closure Unit Process Improvements Reduced Monitoring Alternative Technology Evaluation Portfolio Optimization (time permitting) Discussion
3
RPO Focus Areas
Remediation Process
Optimization
Strategy for Site Closure • Begins with Flexible Design • Defined progress milestones • Land use assumptions/controls • Brownfield approach
Reduced Monitoring • Reduced wells/locations • Reduced frequency • Simplified analytical • Create decision rules • Statistical tools for large sites
Alternative Technologies • Source removal • Permeable barrier walls • Natural attenuation • Sustainable Solutions
Unit Process Improvements • Pumping Effectiveness • Unit process optimization • Alternate or modified treatment • Energy and Sustainability Audits • Life-cycle Optimization
Strategy for Site Closure
5
At-a-glance performance tracking tool to assess progress made toward site closure milestones:
– Achieve 90% run time efficiency – Achieve 75% reduction in in-well
LNAPL thickness and total COC concentration
– Meet interim COC reduction goals of 50%, 75%, and 90% to ultimately achieve site closure approval
– Achieve RGs in a groundwater collection trench and allow for shutdown
Facilitates efficient decision making during OMM
– Reviewed during quarterly RPO meetings
Strategy for Closure - RPO Dashboard Tool
6
RPO Dashboard – Runtime and In-well LNAPL Thickness Tracking
7
Strategy for Closure – New Jersey Case Study Designing for Future Remedy Optimization
Subgrade remedy designed to allow for concurrent redevelopment Fully valved, zoned AS/SVE system,
1200 scfm soil vapor AS/SVE with sequenced bioremediation
contingency – Phase I AS/SVE Operation - Remove xylene “carrier”
fluid and gratuitously bioremediate the secondary contaminants of concern (COCs)
– Phase II Shutdown and Rebound Assessment – If observe production of secondary COCs after return to anaerobic conditions, then enter contingency phase
– Biosparging Contingency Phase – Alternate anaerobic (off) and aerobic (on) conditions to bioremediate secondary COCs to closure criteria
On-going RPO includes: – Operation prioritization – Annual attenuation evaluation – Air permit modifications
8
New Jersey Case Study – Strategy for Closure
Over 800,000 lbs of COCs volatilized and aerobically biodegraded over 6 years
– 89% historical average runtime efficiency – Annual O&M budget reduced 37% – Annual groundwater monitoring budget reduced 30%
Exiting volatilization phase and entering biodegradation-driven remediation phase on schedule
– Initiating assessment of magnitude of residuals and impacts on secondary COCs
Site is now home to one of the highest grossing home improvement stores in the US
RPO program continues to proactively drive site toward closure
Unit Process Improvements
10
Pumping System Optimization
0.0
1.0
2.0
3.0
4.0
5.0
6.0
TCE
Rem
oval
Rat
e (lb
s/ye
ar)
EW-1
EW-2
EW-3
EW-4
EW-5
EW-6
EW-7
EW-8
EW-9
EW-1
0
EW-1
1
EW-1
2
EW-1
3
EW-1
4
EW-1
5
EW-1
6
EW-1
7
EW-1
8
Extraction Wells
11
Optimization Annual Savings
Life-cycle Savings (30 yr)
Cost to Implement
Sustainability Metrics
Turn off 11 of the 18 extraction wells
$90,000 $2.7M
$50,000 22 HP reduction Over 30 Years = 5.8M kwhrs 3900 Tons CO2
Turn off the air stripper and use spray aeration pond
$60,000 $1.8M $65,000 25 HP reduction Over 30 years = 6.6M kwhrs 4400 Tons CO2
Totals $150,000 $4.5M $115,000 12M kwhrs 8300 Tons CO2
Benefits of Pumping/Unit Process Optimization
12
Treating 1500 gpm of chromium VI
contaminated groundwater
High ion exchange resin use creating high O&M costs
Bench scale pilot testing completed to compare alternative resin performance for specific groundwater geochemistry
Ion Exchange Process Optimization
13
New Resin Provides 20X Greater Capacity
13
125000
90000
78000
54000 50000
20000
12000 7000 7000 6000
1800 0
20000
40000
60000
80000
100000
120000
*ResinTech SIR-700 2.5"
*ResinTech WBG30-B
2.5"
*ResinTech SIR-700 5"
*ResinTech SIR-700 40"
*ResinTech SIR-700 20"
*ResinTech WBG30-B 20"
Purolite A500 Purolite A600 ResinTech SIR-1200
Dowex 21K Purolite A100
Bed
Volu
mes
pro
cess
ed b
efor
e re
achi
ng C
r(VI
) cap
acity
Resin Performance
Original
NEW RESIN
ORIGINAL RESIN
*Indicates testing stopped prior to reaching capacity
14
Life-Cycle Cost Comparison
14
Baseline Regenerationa
Off-site Resin Regeneration
On-site Resin Regenerationb
Single-Use Resind
Estimated Capital Cost ($ million)
11.20 7.77 10.07 7.33
Estimated Annual O&M Cost ($ million)
3.57 2.40 2.26 1.93
Estimated Life-Cycle Cost ($ million)c
42.18 28.56 29.63 24.07
a. Off-site regeneration with original purchased resin 21K
b. Prorated cost for the DX plant includes 59 percent of total CRF costs
c. Life-Cycle costs based on 11 year lifetime and discount rate of 4.2%
d. Based on 40,000 bed volume resin change out frequency
15
Sustainability Tracking – 16 MGD Pump and Treat System O&M
Data from monthly electricity, gas bills, fuel purchases, GAC usage are entered into utility accounting system
Output from reports are entered into a master tracking spreadsheet for annual reporting purposes.
Allows for generation of graphics to clearly show effects of optimizations. Normalized metrics for Pump and Treat systems
• kWh per million gallons of water treated • tons of CO2 per million gallons of water treated • tons of GAC and cost per million gallons treated
16
Reduced Monitoring
18
Monitoring Distribution, Frequency, and Analyte
Recommendations
Temporal
Qualitative
Spatial
Monitoring Optimization Approach
A monitoring program must adequately track the effectiveness and protectiveness of a remedy
– Balance cost savings vs. unacceptable loss of accuracy – Optimal monitoring results in minor information loss with large cost reduction
Consider use of qualitative and quantitative analyses – Objectivity and repeatability of dual evaluation provides
increased stakeholder confidence – Statistics and geostatistics used to determine
redundancies in the monitoring network – Qualitative review of program processes
and procedures to determine what is necessary and practical
19
Quantitative Tools to Evaluate Monitoring Reduction
Ricker Plume Stability Method CH2M HILL Plume Moment Analysis Tool Monitoring and Remediation Optimization Software
(MAROS) 3TMO Geostatistical Temporal-Spatial Algorithm (GTS) Spatial Analysis and Decision Assistance (SADA) Geospatial Modeling Tools
– EVS/MVS, SGeMS, geoR, and gstat
20
Before Optimization 14 sites in Program
276 monitoring wells, surface water, and sediment sampling locations sampled semi-annually;
Analyzed for VOCs, SVOCs, and/or natural attenuation indicator parameters;
Monitoring requirements were specified in the decision documents
Optimization Result Monitoring program continues to
address all regulatory requirements; Number of monitoring points reduced
by 50%; Sampling frequency reduced to
annually for 81% of sampling points; Analyte list reduced for nearly all sites; Implementation of low-flow sampling
and PDBs increased field efficiency by more than 50%;
Reduced cost up to $800K
Optimization Process Examined each site’s analyte list, contaminant trends, plume maps, frequency,
well layout, regulatory requirements, sampling procedures, data management, and reporting
For larger sites, ran MAROS to optimize well network
Large Remediation Program Case Study – Monitoring Optimization Example
21
Keys to Successful Monitoring Optimization
Understand that Reduced Monitoring is a common-sense approach – Develop approach based on clear objectives – Implement quantitative and qualitative assessment for more defensible outcomes
to gain stakeholder approval – Use the appropriate tools to support optimum outcomes for the project
Applies similarly to media and process monitoring programs – For example, couple with permit modifications for reduced
monitoring requirements that are consistent with remedy progress
Cost savings are almost always achievable – Carefully balance cost of evaluation versus
savings potential
21
Alternative Technology Evaluation
23
Aggressive Source Removal - Soil Mixing
24
Pre and Post Soil Mixing Groundwater Data (µg/L)
Baseline After 27 months
Ave Median Max Ave Median Max
PCA 56,129 8,550 160,000 0.25* 0.25* 0.25*
TCE 146,064 81,000 490,000 0.72 0.36 2.3
cDCE 96,463 83,000 230,000 329 4.8 1,900
VC 9,763 5,600 29,000 401 1.85 1,300
Baseline – 10 MWs, 27 months – 6 MWs * indicates non-detect, with half detection limit used
25
Soil Mixing Life-Cycle Cost Reduction Example
Capital Cost of $2M Estimated Cost Avoidance
– 60-Years of P&T system operations at $150,000/year
$9M in future expenditures avoided (uninflated)
26
New 45-ft Continuous Trenching Machine For PRB Installations
27
Pump and Treat Replaced By PRB
30-Year Life-Cycle Impacts Pump and Treat System Boundary Biowall
GHG Emissions 460 tons 260 tons
Kilowatt Hours Equivalents Consumed
1,600,000 940,000
30-Year Life-Cycle Cost $18M $7.7M
Assumes Biowall recharged with vegetable oil every 5 years
GSR comparison by Sustainable Remediation Tool (SRT)
Summary
29
Summary Remedial Process Optimization Focus Areas
– Updating Site Closure Strategies – Pumping and Unit Process Improvements – Alternative Technology Evaluations – Reduced Monitoring
Many Tools Are Available to Standardize Approach Case Studies Demonstrate Large Life-Cycle Savings
Questions/Discussion
Portfolio Optimization (time permitting)
32
Improving Remediation O&M Portfolios
Provides consistency and economy of scale in an optimization program and project oversight
Allows prioritization of improvements that provide the greatest reductions in life-cycle costs and focus on site closure.
Contractual arrangements that provide incentive fees based on savings produced by optimization of systems
Full RPO evaluations for large remediation systems that are underperforming or have high life-cycle costs
RPO “lite” for simple systems with lower life-cycle paybacks
33
Site Management Process Optimization (SMPO)
Long-term planning tool for optimization of a portfolio of environmental sites – Optimization of existing remediation systems – Technical support logic for programming and planning – Systematic annual evaluation of site progress and management risk
Collaborative- and consensus-based project to ensure results that meet wide range, and sometimes competing, site management objectives
Establishes a “tool” that can and should be revisited on a regular basis to update the business plan for the portfolio
34
Site Prioritization Example Includes technical performance and site understanding uncertainty scores,
input from risk inventory, and life-cycle costs Low Certainty Score = Large LCC Delta = High Priority
Site Name
Technical Perform Certainty
Site CSM Certainty
Overall Site
Certainty
Estimated Life Cycle
Cost Best Case Worst Case
Optimize Activity
Priority 1 LF-20 83% 66% 73% $420,000 $420,000 $620,000 No
SS-122 100% 98% 99% $245,000 $245,000 $248,000 No
ST-123 64% 52% 59% $2,776,000 $2,776,000 $6,296,500 Yes
SS-124 89% 94% 91% $300,000 $300,000 $341,500 No
SS-125 68% 62% 65% $1,800,000 $1,800,000 $2,710,000 Yes
SS-130 88% 78% 81% $275,000 $275,000 $343,250 No
SS-139 98% 94% 95% $245,000 $245,000 $265,000 No
SS-215 88% 95% 91% $467,114 $467,114 $614,182 No
SS-216 91% 95% 93% $424,257 $424,257 $519,767 No
HYDRANT 63% 47% 57% $1,450,000 $1,450,000 $1,707,500 Yes
Total $8,678,371 $8,678,371 $14,058,699
NOTES: Site is given priority if CSM Certainty < 70% OR deviation between Best Case and Worst Case is > 1.5. LCC = life-cycle cost to complete "Complete" is defined as a site-specific site management endpoint including long-term care LUCs or clean closure. Limit of 30 years.
top related