Session 4 Paving the path to success: Data driven solutions Erik - PowerPoint PPT Presentation

Session 4 Paving the path to success: Data driven solutions Erik Gaiser, PG Wildermuth Environmental Treatment technologies for removing contaminants of emerging concern: 1,4-dioxane, 1,2,3-TCP, PFOA/PFOS, perchlorate, and Cr6 Nicole Blute, PhD, PE Orange County Water District PFAS: How we got here and legal options going forward Richard Head SL Environmental Law Group PC Chino Basin Water Quality Colloquium May 2, 2019

Paving the path to success: Data driven solutions Chino Basin Water Quality Colloquium May 2, 2019

Houston…We Have a Problem Chino Basin Water Quality Colloquium Slide 2

Where to Start “If you know yourself and know your enemy, you need not fear the results of a hundred battles. If you know yourself but not the enemy, for every v victory gained you will also suffer a defeat. If you know neither t the enemy n nor yourself, y you will succumb in every battle.” The Art of War Sun Tzu, 500 B.C. Chino Basin Water Quality Colloquium Slide 3

How Much is Enough to Solve the Problem? Complexity DATA DATA Chino Basin Water Quality Colloquium Slide 4

What Bulk Sample Results Mean • High volume groundwater samples are not an average concentration • Stratification of water quality can occur due to variations in aquifer structure and materials • Flow is concentrated in high permeability zones (K > 10 -4 ) • Mass is stored in low permeability zones (K < 10 -4 ) • Provides conductivity proportional result Results are biased toward water quality in higher o K zones Chino Basin Water Quality Colloquium Slide 5

When is a Bulk Sample is Enough? Blending Wellhead Treatment Chino Basin Water Quality Colloquium Slide 6

When You Need Something More Passive Diffusion Bags Low-Flow Bladder and Piston Pumps Bomb Samplers HydraSleeve Chino Basin Water Quality Colloquium Slide 7

Best Available Technology Combined Well-Bore Flow and Depth-Dependent Water Sampler Chino Basin Water Quality Colloquium Slide 8

Commercially Licensed to BESST Improvements to the USGS Tooling • Horizontal dye injection to compensate for wells that are off from vertical • Smaller diameter gas piston pump Capable of sampling at depths up to o 1200 ft Can fit in vent tubes or other ports o with 1” -diameter ID or larger • Capable of being run under ambient or operating conditions • Concentration is C a =(C i Q i -C i+1 Q i+1 )/Q a • Flow is Q=(V 𝝆𝒔 𝟑 ) • Where V=(d 2 -d 1 )/(t 2 -t 1 ) Chino Basin Water Quality Colloquium Slide 9

A Growing Compendium of Data ~800 Production Wells Highly to Moderately Stratified profiled in California • Arsenic • Iron • Fluoride • Hydrogen sulfide • Uranium • Color • Many anthropogenic contaminants Moderately Stratified • Boron • Manganese • Chrome VI Chino Basin Water Quality Colloquium Slide 10

Case Study – Naturally Occurring Contaminants Flow Profiling Average Well Head Concentrations (initial) 1860 GPM As = 12.5 µgl Fe = 145 µgl Mn = 64 µgl • As and Mn above MCLs 282-310 ft – 12% • 1950’s well log with basic lithology 310-330 ft – 3% 390-400 ft – 0% % of Flow 400-410 ft – 0% • Operating Mn wellhead treatment 480-500 ft – 3% 15% system 500-520 ft – 2% 520-540 ft – 2% 0% • Well profiling completed in 2 days 540-570 ft – 5% • Performed under operating 12% 620-640 ft – 12% conditions with no modification to 640-660 ft – 0% the well 660-680 ft – 0% 29% • Flow profiling done first 680-700 ft – 15% 700-720 ft – 2% 880-900 ft – 1% 740-776 ft – 9% • Profiling costs = $22,000 10% 900-920 ft – 0% 810-830 ft – 1% 920-940 ft – 2% 16% 940-960 ft – 10% 1070-1090 ft – 5% 960-970 ft – 3% 1090-1110 ft – 3% 1000-1010 ft – 1% 2% 1110-1130 ft – 2% 1010-1020 ft – 1% 1130-1140 ft – 1% 16% 1140-1160 ft – 2% Data courtesy of Sand/Silt 1160-1180 ft – 3% Clay Chino Basin Water Quality Colloquium Slide 11

Case Study Contaminant Profiling Average Well Head Concentrations (initial) 1860 GPM As = 12.5 µgl Fe = 145 µgl Mn = 64 µgl As, Fe, and Mn at concentrations above the % of Flow As MCL = 10 µgl Fe MCL = 300 µgl Mn MCL = 50 µgl MCLs occur in isolated 15% and discrete intervals 0% 12% 29% 10% 16% 2% 16% Data courtesy of Sand/Silt Clay Chino Basin Water Quality Colloquium Slide 12

Case Study Remedy and Results Average Well Head Concentrations After Modification 1775 GPM Remedy As = Fe = Mn = 38 µgl 6.4 µgl Non-detect • Install sleeve with packers to isolate high As, Fe, and Mn from the rest New Flow As MCL = 10 µgl Fe MCL = 300 µgl Mn MCL = 50 µgl of the well Results • Lost ~5% of production capacity • Mn wellhead treatment system taken offline • $2.5M treatment system for As no longer required Data courtesy of Sand/Silt Clay Chino Basin Water Quality Colloquium Slide 13

Another Success Story Chino Basin Water Quality Colloquium Slide 14

A Closer Look at Heterogeneity • Variations in permeability occur on a very small scale • Studies of the Borden Aquifer have shown that simple changes in the packing arrangement can result in orders of magnitude change in permeability • How does this impact the transport of anthropogenic compounds? • Transport concentrated in high permeability soils (K > 10 -4 ) • Short term storage in soils with 10 -4 cm/sec 10 -2 cm/sec 10 -6 cm/sec permeability ~10-4 • Storage concentrated in low permeability soils (K < 10-4) Chino Basin Water Quality Colloquium Slide 15

Permeability Dominates Anthropogenic Contaminant Transport • Near zero dispersivity • Contaminant concentrations can change by orders of magnitude over small intervals (think foot scale) • Results in 90% of mass moving in ~10% of the aquifer • Extremely inefficient to treat the whole aquifer Chino Basin Water Quality Colloquium Slide 16

Predominant Approach to Anthropogenic Contaminants 2000 GPM • The objectives of production and the new % of Flow generation of remediation are at odds with PCE = 1,000 ppb each other 15% (300 GPM) • Long screens on production wells are 0% problematic 12% High probability of drawing contaminants down o through the aquifer High probability of not capturing all the mass 29% o • One recent case study of two production wells 10% Well screens 150 - 200 feet in length o 1 st well pumping at 2,000 GPM o 16% Only 80 GPM of which had contaminants • 2 nd well pumping at 1,000 GPM 2% o Only 35 GPM of which had contaminants • 16% Sand/Silt Clay Chino Basin Water Quality Colloquium Slide 17

Don’t Treat it Like Naturally Occurring Contaminants 2000 GPM % of Flow PCE = 1,000 ppb 0% 0% 20% 29% 10% 16% 4% 19% Sand/Silt Clay Chino Basin Water Quality Colloquium Slide 18

Don’t Treat it Like Naturally Occurring Contaminants 2000 GPM % of Flow PCE = 1,000 ppb 0% 0% 20% 29% 10% 16% 4% 19% Sand/Silt Clay Chino Basin Water Quality Colloquium Slide 19

It’s Time to Rethink Taking a Page From the Environmental Community 2000 GPM 100 GPM % of Flow PCE = 1,000 ppb • If you can afford to lose the production 100% capacity…isolate the zone(s) with contaminants 0% • Focus extraction on that zone(s) but at 0% substantially reduced flow rate • Potential benefits include: 0% • Significantly smaller treatment system • No probability of drawing contaminants 0% down through the aquifer 0% 0% 0% Sand/Silt Clay Chino Basin Water Quality Colloquium Slide 20

It’s Time to Rethink Taking a Page From the Environmental Community 2000 GPM 50 GPM % of Flow PCE = 1,000 ppb • If you can’t afford to lose the production 15% capacity…consider an intercept well(s) 0% • Focus extraction on the 10% of the system 12% carrying 90% of the mass • Pump at a substantially reduced flow rate 29% • Potential benefits include: • Significantly smaller treatment system 10% • Minimized probability of drawing contaminants down through the aquifer 16% 2% 16% Sand/Silt Clay Chino Basin Water Quality Colloquium Slide 21

Key Takeaways • Know yourself – what is your timeframe for implementation, what are your cost constraints, and what are your most likely treatment options • Know your enemy – what is the contaminant, how does it behave in the environment, and where exactly is it entering the well • Naturally occurring contaminants typically occur in very discrete intervals There is often the opportunity to isolate these zones using a sleeve-packer system o Pump from above/below the packered interval o Doing so can result in cost savings up to 90% in comparison to wellhead treatment systems o • Think/do the opposite for anthropogenic contaminants There is often the opportunity to isolate contaminated zones using a sleeve-packer system o Pump from within the packered interval or install an intercept well(s) upgradient o Focused extraction can be done at substantially lower rates o Potential cost savings in smaller, more effective treatment systems o • We need to re-evaluate using productions wells for contaminant remediation Chino Basin Water Quality Colloquium Slide 22

With the Right Data We Have a Path to Success Chino Basin Water Quality Colloquium Slide 23

Thank you Paving the path to success: Data driven solutions Erik Gaiser, PG Wildermuth Environmental egaiser@weiwater.com Chino Basin Water Quality Colloquium May 2, 2019