11th California Unified Program Annual Training Conference

1
11th California Unified Program Annual Training
Conference
Interpreting LUFT Remediation Data for System
Optimization Course M-F4 Time 3-5pm January
26, 2009
Moderator Ben Heningburg, P.G. State Water
Resources Control Board, UST Cleanup Program,
[phone], bheningburg_at_waterboards.ca.gov
2
Main Topics

• What remediation system data should you collect?
• Where are the sampling and data collection
  points located on typical soil vapor and
  groundwater extraction systems?
• When should remediation system data be
  collected?
• Why is it important to collect sufficient
  system data?
• Who should be involved in the planning and
  operation of remediation systems?

3
Presenters
Bob Sloan, P.E. Remediation Engineer Chickadee
Remediation, [phone] richardsloan_at_chickadee
usa.com, Eric Swensen, P.E. Environmental
Remediation Specialist Merced County Division of
Environmental Health, [phone],
eswenson_at_co.merced.ca.us, Ben Heningburg, P.G.
Engineering Geologist State Water Resources
Control Board, [phone], bheningburg_at_waterbo
ards.ca.gov
4
11th Annual CaliforniaUnified Program Training
ConferenceJanuary 26-29, 2009Garden Grove,
CaliforniaRichard SloanCalifornia
Remediation of GasolineSpills and Leaks
5
Gasoline Release Management Program

• Status of potential pathways
• Receptor protection
• Source identification and control
• Nature and extent of soil, groundwater, and vapor
  impacts
• Physical characteristics of the subsurface
• Properties of the chemicals present in the soils
  and groundwater
• Develop/implement the appropriate technology
  sequence

6
Gasoline Release Management Program

• Design, Construction, and Operation
• Health, safety, and quality take priority
• Use standard sized pumps, meters, valves,
  controls, instruments, etc.
• Allow for "easy" changes and modifications in
  response to progress results
• Field fit most of mechanical and electrical
• Realistic cost and schedule
• Commit the necessary resources

7
Bucks Co./Montgomery Co.

• Reviewed eight service stations in detail
• All had leaking underground storage tanks
• Operating issues accurate inventory control,
  consistently negative inventory
• Shallow bedrock (varying depths)
• Groundwater in unconsolidated sediments is the
  critical zone
• MTBE and BTEX tended to co-exist in the impacted
  groundwater
• Numerous active water supply wells accelerated
  MTBE and BTEX migration

8
Pools Corner
9
Bucks Co./ Montgomery Co.

• Slow response to evidence of gasoline spills or
  leaks
• Inadequate response action for 10 years or more
  allowed plumes to grow
• Private wells were impacted
• Groundwater is best protected by early detection
  and rapid response
• Groundwater monitoring next to UST systems may
  have detected plumes while still small and easy
  to remediate

10
Bucks Co./ Montgomery Co.

• Receptors have been protected by point of entry
  treatment (POET) systems and bottled water
• Focused source control has been effective
• SVE and pump and treat have been effective
• MTBE and BTEX concentrations decreased

11
Effects of Temperature on VP
12
SolubilityWater, Hydrocarbons, Ethanol

• When a lot of ethanol is present (gt70)
• Gasoline and water become completely miscible
  with each other and all 3 merge into a single
  phase
• When less ethanol gasoline, and waterethanol
• Can happen with 0.5 water by mass and 10
  ethanol by volume separation to two phases
• Ethanol is added at terminals, not at refineries

13
(No Transcript)
14
Compounds at lower concentrations are lost to
dilution and reported at Below Detection
Limit(lt50 ppb)
TBA
MTBE
Benzene
15
Outline of Workshop

• Introduction
• Properties, fate and transport
• Site assessment and analytical issues
• Applying remedial technologies
• Case studies of remediation
• Conclusion and summary

16
Immediate Response to Protect Receptors
17
Free-Product Removal

• Skimming Methods
• Continuous belt separation
• Spiral pump at the interface
• Smart pumps
• Multi-phase extraction
• Two-Phase Extraction (TPE)
• Vapor and liquid extracted together
• Dual-Phase Extraction (DPE)
• Gas and liquid extracted separately

Example of a smart pump
18
In-situ Thermal Desorption
Courtesy Remedial Operations Group
McMillan-McGee
19
Soil Vapor Extraction

• TBA/Ethanol MTBE
• SVE effective ? ?
• High air flow rates to strip VOCs ? ?
• Treats unsaturated zone ? ?
• Expand vadose zone ? ?
• Aboveground gas treatment by
• Granular activated carbon -- ?
• Catalytic oxidation ? ?
• Thermal oxidation ? ?
• Biofilters ? ?

20
Relative Oxidizing Power of Chemical Oxidants
AEHS Journal-2002 Special Oxygenated Fuels Issue
(page 71)
21
DRIS Oxidant Delivery
22
In Situ GW Bioremediation Approaches

• TBA MTBE
• Directly inject amendments ? ?
• Extract, amend, and re-inject ? ?
• Diffuse amendments into GW ? ?

23
Phytoremediation

• TBA/Ethanol MTBE
• Gradient control/evapotranspiration ? ?
• Rhizosphere biodegradation ? ?
• Native species perform best ? ?
• Low maintenance conditions
• Plant selection influenced by water balance ? ?
• Model transpiration rate, stand density
• Irrigation often required to establish stand ?
  ?
• Deep watering stimulates deep roots
• Water/soil quality affects establishment ? ?
• Salt concentration, pH

24
(No Transcript)
25
(No Transcript)
26
Natural Attenuation Processes

• TBA MTBE
• Destructive (mass reduction)
• Intrinsic biodegradation ? ?
• Abiotic chemical reactions -- ?
• Non-destructive (mass conservative)
• Adsorption -- ?
• Dispersion ? ?
• Advection ? ?
• Diffusion ? ?
• Volatilization -- ?
• Dilution ? ?

27
Case Studies

• Bayport, TX
• Elevated levels of TBA in shallow groundwater
  source control was effective confirm biological
  component of TBA natural attenuation
• Westheimer and Shepherd, TX
• Gas station and dry cleaner plumes co-mingled
  effective source control was critical pump and
  treat with in-situ bioremediation
• Omaha, NE
• Three LUSTs BTEX, TBA, and MTBE plumes are well
  defined responded rapidly to pump and treat and
  circulating in-situ bio

28
Long Beach, CA Description

• Abandoned gas station on 0.6 acre corner lot
• Tanks may have leaked 500 gallons of gasoline
  (1980-1995)
• Three leaking tanks removed
• 60 yd3 soil with free-phase to landfarm
• Commercial use area being upgraded
• No at-risk receptors
• Groundwater plume well defined, 12 years of
  monitoring
• Groundwater impacted to about 30' bgs
• BTEX, MTBE, TBA are the chemicals of concern

29
Long Beach, CA Remediation

• Remove tanks and soils with free-phase
• Backfill tank area with clean soils amended with
  5 lbs. KMnO4 per ton
• Soil vapor extraction
• Three 6" diameter wells
• Screened from 5' to 20' bgs
• Extract 10 CFM per well
• Operate for 9 months
• Treat vapor with GAC

30
Long Beach, CA
31
Long Beach, CA
Long Beach, CA
32
Long Beach, CA
33
Channelview, TX Active System

• Remedial Action
• Source control
• Pump and treat
• In-situ bioremediation
• Oxygen and nutrient addition
• Site
• Petrochemical plant setting
• Leaking process sump
• Source control completed by replacing sump
• Plume defined in detail
• Natural attenuation on leading edge
• Dissolved plume remediation required

34
Channelview, TX Active System

• Design for 12-18 month breakthrough
• Oxygen source and nutrients
• Supplemental food (corn syrup)
• Establish circulation
• Periodic microbe amendment
• Carbon adsorption testing

35
PNW Ethanol Concentrations 6/99 and 4/01
Buscheck et al., 2001
36
PNW Ethanol and DTW versus Time
Buscheck et al., 2001
37
PNW Ethanol and DTW versus Time
Buscheck et al., 2001
38
Cosolvent Effect and Depletion of Electron
Acceptors Benzene, TPH Ethanol Concentrations
versus Time
Buscheck et al., 2001
39
PNW Terminal Methanogenesis

• Highest methane concs. were measured more than 2
  years after the release
• Groundwater
• Methane concs. generally increased from 6/00 to
  6/01, then decreased a bit in final 7/01 round
• Max. gt 30,000 ug/l
• Methane plume larger than ethanol plume
• Soil Gas
• LEL 50,000 ppmv (5 by volume)
• UEL 150,000 ppmv (15 by volume)
• Methane concs. gt UEL at 4 bgs in area of highest
  dissolved methane

Buscheck et al., 2001
40
(No Transcript)
41
Westheimer Shepherd (Houston, TX)

• Remediation (continued)
• In-situ bioremediation
• Six extraction wells
• Six 6" diameter injection wells screened from
  20' bgs to 35' bgs
• Pump 0.5 to 1.0 gpm per well
• Start in-situ bio after 9 months of pump and
  treat
• Treat groundwater with GAC
• Add K2SO4 (10 ppm) and NH3NO3 (5 ppm) and inject
• Add 40 ppm O2 after TCE reaches 1,000 ppb

42
Westheimer Shepherd (Houston, TX)

• Remediation (continued)
• Monitored natural attenuation
• 10-year data base
• 4-year MNA
• Steady decrease
• No at-risk receptors

43
Westheimer Shepherd (Houston, TX)

• Results/Comments
• Significant impact on adjacent properties
• Construction excavation the only risk
• Cooperation/access required from adjacent
  property owners
• Presence of TCE delayed use of aerobic
  bioremediation
• Chlorinated with the BTEX, TBA, and MTBE in the
  plumes complicated the remediation sequence
• TBA "stalled" until converted to aerobic in-situ
  bioremediation

44
Gas Station/Mini Mart (Omaha, NE)

• Description
• Two USTs leaked for over 10 years
• Soil and groundwater impacted to 30' bgs
• Potable wells 600' downgradient have been
  impacted
• POET systems have been installed at 28 residences
• Removed LUSTs and 300 yd3 of contaminated soil
• Property is prime commercial real estate

45
Omaha, Nebraska
46
Gas Station/Mini Mart (Omaha, NE)

• Remediation
• Soil vapor extraction, thermal oxidation, and
  pump and treat
• Free-phase zones
• High concentration dissolved zones
• 200 scfm from six 6" diameter extraction wells
• Treat vapor with thermal oxidizer for 4 months
  then treat with GAC

47
Gas Station/Mini Mart (Omaha, NE)

• Remediation (continued)
• Pump and treat 4.5 gpm via activated sludge unit
  for 9 months then treat with GAC
• Discharge treated water to POTW for 9 months
• Convert to circulating in-situ anaerobic
  bioremediation during month 9
• K2SO4 5 ppm as SO4
• NH4NO3 10 ppm as NO3
• Convert to monitored natural attenuation
• Benzene lt 120 ppb
• MTBE lt 150 ppb
• TBA lt 200 ppb

48
(No Transcript)
49
Omaha, Nebraska
50
Outline of Workshop

• Introduction
• Properties, fate and transport
• Site assessment and analytical issues
• Applying remedial technologies
• Case studies of remediation
• Conclusion and summary

51
Measurement of Metals in Groundwater

• 2009 CUPA Conference

52

• DEPARTMENT OF PUBLIC HEALTH
• Division of Environmental Health

Eric Swenson, P.E. Civil and Mechanical
Engineer Project Engineer eswenson_at_co.merced.ca.us
53
Major Assumption

• This presentation is based upon the assumption
  that unconsolidated formations are being studied
  as are commonly found in the central valley of
  California and that groundwater present in clays
  are being sampled.

54
Former Standard Protocol for Sample Preparation
for Metals Analysis

• Groundwater sample collected in disposable bailer
  after purging of monitor well.
• Groundwater filtered through 0.5 µm filter.
• Filtered sample placed in acidified sample
  container and transported to laboratory for
  analysis.
• Laboratory completes EPA Method 6010 analysis on
  groundwater sample.

55
Data Reported from LOP 24230-Highest Groundwater
Concentrations Measured (µg/L)
56
Data Reported from LOP 24207-Highest Groundwater
Concentrations Measured (µg/L)
57
Data Reported from LOP 24278-Highest Groundwater
Concentrations Measured (µg/L)
58
Is There a Major Dissolved Metals Problem in Los
Banos?

• All samples filtered prior to acidification.
• All samples collected from established monitor
  wells.
• Multiple repeat sampling events with similar
  results.
• What is going on ?

59
The First Clue
Post filtration sediment observed after sample
sitting in ice chest for more than 1 hour.
60
How Small are Clay Particles?
If the top size for clay is 2 micro meters, what
is the bottom size? How much material is below
0.45 micro meters?
61
A Simple Plan

• Collect an un-acidified groundwater sample (at
  least 125 of desired sample volume) and let it
  decant for hours in a cooled ice chest.
• Remove the supernatant with a clean turkey baster
  and filter with 0.45 micron filter.
• Place the supernatant into an acidified sample
  container.

62
Solids Settling Example
Collect some Merced soil and mix well with water
and let sit undisturbed.
63
Time 0
Time 15 min.
Time 30 min.
Time 4 hrs.
Time 8 hrs.
Time 23 hrs.
Time 51 hrs.
Settling time will likely vary by particle size,
particle shape, particle loading, and water
temperature.
64
Turkey Baster Decanting Dos
Collect undisturbed water samples from the clean
supernatant.
65
Turkey Baster Decanting Donts
Dont collect samples too close to the solids in
the bottom of the settling container leave some
liquid in the settling container.
66
Filtration Following Decanting
Complete 0.45 micron filtration of supernatant
prior to acidification.
67
The Results from the 3 Sites of the Turkey Baster
Method
68
Data Reported from LOP 24230- Groundwater
Concentrations Measured (µg/L)(with alternate
sample preparation method)
69
Data Reported from LOP 24207-Groundwater
Concentrations Measured (µg/L)(with alternate
sample preparation method)
70
Data Reported from LOP 24278-Groundwater
Concentrations Measured (µg/L)(with alternate
sample preparation method)
71
Comparison of Cr Data for Select Monitor Wells
72
Cr6 Comparison for Select Monitor Wells
73
Comparison of Arsenic Data for Select Monitor
Wells
74
What Have We Learned?

• Los Banos area appears to have very fine clays in
  soils adjacent to first encountered groundwater.
• Settling, decanting, and filtration of
  groundwater samples prior to acidification
  appears to remove most if not all of the fine
  suspended soil particles in the groundwater
  samples.
• Data collected with this approach appears to
  generate reasonable results for groundwater
  metals concentrations where clays are present.
• If the data doesnt look right, there may be a
  reason.

75
Considerations for Groundwater Metals Analysis in
Conjunction with Oxidant Injection

• Collecting baseline concentrations of total Cr,
  Cr6, and As is a good practice prior to oxidant
  injection
• Utilizing an alternate groundwater sample
  preparation approach that removes all suspended
  soil particles prior to acidification should
  provide an accurate measure of dissolved metals
  in groundwater.
• Existing sites with on-going oxidant injection
  could benefit with this sample preparation
  approach if past data indicates significant
  changes in total Cr or As concentrations.

76
Other Approaches?
There are certainly other approaches to removing
submicron particles from groundwater samples.
Use of centrifuges is one alternative approach.
What has become clear is that if dissolved phase
metals results are desired from groundwater
samples with suspended clay particles, these fine
particles must first be removed prior to
acidification of the sample.
77

• Thanks to the regulators and consultants who have
  taught me how much there is to learn about
  groundwater assessment and thankfully Im still
  learning.

78
Multiphase ExtractionData Collection and
Analysis
Ben I. Heningburg, P.G. State Water Resources
Control Board UST Program
CUPA Conference 2009 Garden Grove, CA
79
Outline

• Methods of Extraction
• Single Phase (Water or Vapor)
• Dual Phase (Separate Water and Vapor Streams)
• Multi-Phase (Includes Free Product)
• Two Phase (Combined Stream)
• Pilot Test Data
• Data Collection
• Data Analysis

80
Methods of Extraction
Dual Phase Extraction (DPE) Extraction of both
vapor and water using two separate flow streams
(down hole pump and vapor extraction).
James Jacobs and Mehmet Pehlivan, TWO-PHASE
EXTRACTION METHODS, APPLICATIONS FOR GROUNDWATER
AND SOIL REMEDIATION18th Annual AEHS Meeting and
West Coast Conference on Soils, Sediments, and
Water March 10-13, 2008, San Diego, CA
81
Methods of Extraction (Cont.)
Multiphase Extraction (MPE) Extraction of free
floating hydrocarbons, water and vapor in a
combined flow stream using a vacuum source and a
drop tube (also referred as Bioslurping).
James Jacobs and Mehmet Pehlivan, TWO-PHASE
EXTRACTION METHODS, APPLICATIONS FOR GROUNDWATER
AND SOIL REMEDIATION18th Annual AEHS Meeting and
West Coast Conference on Soils, Sediments, and
Water March 10-13, 2008, San Diego, CA
82
Methods of Extraction (Cont.)
Two-Phase Extraction (TPE) Extraction of both
vapor and water in a combined flow stream using a
vacuum source and a drop tube.
James Jacobs and Mehmet Pehlivan, TWO-PHASE
EXTRACTION METHODS, APPLICATIONS FOR GROUNDWATER
AND SOIL REMEDIATION18th Annual AEHS Meeting and
West Coast Conference on Soils, Sediments, and
Water March 10-13, 2008, San Diego, CA
James Jacobs and Mehmet Pehlivan, TWO-PHASE
EXTRACTION METHODS, APPLICATIONS FOR GROUNDWATER
AND SOIL REMEDIATION18th Annual AEHS Meeting and
West Coast Conference on Soils, Sediments, and
Water March 10-13, 2008, San Diego, CA
83
Benefits of Two-phase Extraction

• Cost effective.
• Strips VOCs during extraction (99 stripping
  efficiency is possible).
• Low cost of well maintenance and wellhead
  installation.
• Reduces the O M cost for combined groundwater
  and soil treatment systems.
• Increases hydrocarbon mass removal.
• Enhances bioremediation/induce bioventing.
• Approved by most regulatory agencies for soil and
  groundwater remediation.
• Can be used as a complement to bio-remediation
  and in-situ chemical oxidation systems.

84
Contaminant Type and Source

• Contaminant Type
• Petroleum Hydrocarbons
• LNAPL
• Chlorinated Hydrocarbons
• Mixed Plume (VOC Perchlorate Metals)
• DNAPL
• Contaminant Source
• UST/AST
• CLARIFIER
• LANDFILL
• Pipeline

85
Data Collection for System Design

• Pre-test data and setup
• Before-Collect groundwater (GW) grab samples.
• Use wellhead assembly that will allow for data
  collection at each wellhead.
• Test data (Readings taken at same port/location)
• During - Collect periodic GW samples at wellhead.
• During - Collect periodic vapor samples. (use
  clean equip.)
• Flow Readings (SCFM).
• Vacuum Readings- Provide readings in inches of
  mercury and inches of water.
• Temperature Readings.
• During Collect periodic depth to water changes
  at wellhead.
• Extracted groundwater Readings
• Use preliminary data sheets to evaluate
  remediation goals and objectives on a weekly to
  bi-weekly basis.

86
Data Collection for System Design (Cont.)
B
Flow Splitter (Air-Water Ratio) A- Vacuum in
inches of water B - Air flow meter C -
Temperature gauge D - Vacuum in inches of
mercury E- Sample port
A
C
D
E
James Jacobs and Mehmet Pehlivan, TWO-PHASE
EXTRACTION METHODS, APPLICATIONS FOR GROUNDWATER
AND SOIL REMEDIATION18th Annual AEHS Meeting and
West Coast Conference on Soils, Sediments, and
Water March 10-13, 2008, San Diego, CA
James Jacobs and Mehmet Pehlivan, TWO-PHASE
EXTRACTION METHODS, APPLICATIONS FOR GROUNDWATER
AND SOIL REMEDIATION18th Annual AEHS Meeting and
West Coast Conference on Soils, Sediments, and
Water March 10-13, 2008, San Diego, CA
87
Drawdown in Observation Wells
James Jacobs and Mehmet Pehlivan, TWO-PHASE
EXTRACTION METHODS, APPLICATIONS FOR GROUNDWATER
AND SOIL REMEDIATION18th Annual AEHS Meeting and
West Coast Conference on Soils, Sediments, and
Water March 10-13, 2008, San Diego, CA
James Jacobs and Mehmet Pehlivan, TWO-PHASE
EXTRACTION METHODS, APPLICATIONS FOR GROUNDWATER
AND SOIL REMEDIATION18th Annual AEHS Meeting and
West Coast Conference on Soils, Sediments, and
Water March 10-13, 2008, San Diego, CA
88
Vacuum Response in Observation Wells
James Jacobs and Mehmet Pehlivan, TWO-PHASE
EXTRACTION METHODS, APPLICATIONS FOR GROUNDWATER
AND SOIL REMEDIATION18th Annual AEHS Meeting and
West Coast Conference on Soils, Sediments, and
Water March 10-13, 2008, San Diego, CA
James Jacobs and Mehmet Pehlivan, TWO-PHASE
EXTRACTION METHODS, APPLICATIONS FOR GROUNDWATER
AND SOIL REMEDIATION18th Annual AEHS Meeting and
West Coast Conference on Soils, Sediments, and
Water March 10-13, 2008, San Diego, CA
89
Concentrations in Extracted Groundwater
James Jacobs and Mehmet Pehlivan, TWO-PHASE
EXTRACTION METHODS, APPLICATIONS FOR GROUNDWATER
AND SOIL REMEDIATION18th Annual AEHS Meeting and
West Coast Conference on Soils, Sediments, and
Water March 10-13, 2008, San Diego, CA
James Jacobs and Mehmet Pehlivan, TWO-PHASE
EXTRACTION METHODS, APPLICATIONS FOR GROUNDWATER
AND SOIL REMEDIATION18th Annual AEHS Meeting and
West Coast Conference on Soils, Sediments, and
Water March 10-13, 2008, San Diego, CA
90
Sampling Ports
System Schematic A, B, C, E, and F show the
water sample locations where stripping test
samples were collected.
James Jacobs and Mehmet Pehlivan, TWO-PHASE
EXTRACTION METHODS, APPLICATIONS FOR GROUNDWATER
AND SOIL REMEDIATION18th Annual AEHS Meeting and
West Coast Conference on Soils, Sediments, and
Water March 10-13, 2008, San Diego, CA
James Jacobs and Mehmet Pehlivan, TWO-PHASE
EXTRACTION METHODS, APPLICATIONS FOR GROUNDWATER
AND SOIL REMEDIATION18th Annual AEHS Meeting and
West Coast Conference on Soils, Sediments, and
Water March 10-13, 2008, San Diego, CA
91
Calculations
James Jacobs and Mehmet Pehlivan, TWO-PHASE
EXTRACTION METHODS, APPLICATIONS FOR GROUNDWATER
AND SOIL REMEDIATION18th Annual AEHS Meeting and
West Coast Conference on Soils, Sediments, and
Water March 10-13, 2008, San Diego, CA
James Jacobs and Mehmet Pehlivan, TWO-PHASE
EXTRACTION METHODS, APPLICATIONS FOR GROUNDWATER
AND SOIL REMEDIATION18th Annual AEHS Meeting and
West Coast Conference on Soils, Sediments, and
Water March 10-13, 2008, San Diego, CA
92
Key Observations

• Have a good understanding of subsurface
  environment
• Continuous sampling in vadoze and saturated zone,
• CPT/MIP/ROST Survey,
• Petrophysical testing (capillary curve)
• Groundwater flow regimes
• Perform a pilot test
• Vacuum and water drawdown zone of influence
• HC concentrations in the extracted water and in
  the extraction wells
• Rebound test
• Wellhead flow (water and Vapor) flow measurements

Questions Thank You Example tables and slides
available upon request. bheningburg_at_waterboards.c
a.gov
93
Questions

• Supplemental information
• Chickadee Remediation Company
  www.chickadeeusa.com
• Merced County Division of Environmental Health -
  http//merced.networkofcare.org/eh/home/index.cfm
• State Water Resources Control Board -
  http//www.waterboards.ca.gov/water_issues/program
  s/ust/

Thanks