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Issam Najm, Ph.D., P.E. 2015 Environmental & Occupa6onal Health Technical Symposium California State University Northridge March 4, 2015
Issam Najm, Ph.D., P.E.
2015 Environmental & Occupa6onal Health Technical Symposium California State University Northridge
March 4, 2015
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1. The San Fernando Basin 2. Groundwater Contamina?on
3. Current Treatment Systems
4. Treatment Op?ons, Challenges, & Poten?al Cost
5. Closing Remarks
Closing Remarks
Treatment Op?ons
Current Treatment
Groundwater Contamina?on
San Fernando Basin
4 Closing Remarks
Treatment Op?ons
Current Treatment
Groundwater Contamina?on
San Fernando Basin
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1. Total LADWP water right out of the SF Basin is 87,000 AFY
2. That’s 1,000 acres filled with 87 feet of water, every year… 3. LADWP’s total annual water demand is between 550,000 &
600,000 AF
4. Groundwater can be between 10% of total LADWP demand during wet years, and up to 30% of demand during dry years
5. 80% of LA’s groundwater is in the SF Basin 6. However, the SF Basin is highly contaminated with chemicals
Closing Remarks
Treatment Op?ons
Current Treatment
Groundwater Contamina?on
San Fernando Basin
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2015 1980 1990 2000 2010 1995 1985
1980: VOCs detected in a large number of SFV produc6on wells
1986: SFV, Area 1 Superfund Site added to Na6onal Priori6es List (NPL)
1989: North Hollywood Operable Unit (NHOU) began GW treatment
Closing Remarks
Treatment Op?ons
Current Treatment
Groundwater Contamina?on
San Fernando Basin
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2015 1980 1990 2000 2010 1995 1985
1996: Burbank OU became Opera6onal
2003–2007: New chemicals detected at high levels (TCP, 1,4-‐dioxane, NDMA & Perchlorate)
2009: New Remedy approved by EPA for NHOU to address Cr6 and 1,4-‐dioxane
Closing Remarks
Treatment Op?ons
Current Treatment
Groundwater Contamina?on
San Fernando Basin
8 Closing Remarks
Treatment Op?ons
Current Treatment
Groundwater Contamina?on
San Fernando Basin
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9 Closing Remarks
Treatment Op?ons
Current Treatment
Groundwater Contamina?on
San Fernando Basin
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10 Closing Remarks
Treatment Op?ons
Current Treatment
Groundwater Contamina?on
San Fernando Basin
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210
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North Hollywood
Crystal Springs
Pollock
11 Closing Remarks
Treatment Op?ons
Current Treatment
Groundwater Contamina?on
San Fernando Basin
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12 Closing Remarks
Treatment Op?ons
Current Treatment
Groundwater Contamina?on
San Fernando Basin
Source: U
SEPA
(200
5 – 20
10 Data)
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13 Closing Remarks
Treatment Op?ons
Current Treatment
Groundwater Contamina?on
San Fernando Basin
Source: U
SEPA
(200
5 – 20
10 Data)
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14 Closing Remarks
Treatment Op?ons
Current Treatment
Groundwater Contamina?on
San Fernando Basin
Source: U
SEPA
(200
5 – 20
10 Data)
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210
5
15 Closing Remarks
Treatment Op?ons
Current Treatment
Groundwater Contamina?on
San Fernando Basin
Source: U
SEPA
(200
5 – 20
10 Data)
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210
5
16 Closing Remarks
Treatment Op?ons
Current Treatment
Groundwater Contamina?on
San Fernando Basin
Source: U
SEPA
(200
5 – 20
10 Data)
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210
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17 Closing Remarks
Treatment Op?ons
Current Treatment
Groundwater Contamina?on
San Fernando Basin
Source: U
SEPA
(200
5 – 20
10 Data)
5
210
5
18 Closing Remarks
Treatment Op?ons
Current Treatment
Groundwater Contamina?on
San Fernando Basin
Source: U
SEPA
(200
5 – 20
10 Data)
5
210
5
19 Closing Remarks
Treatment Op?ons
Current Treatment
Groundwater Contamina?on
San Fernando Basin
Source: U
SEPA
(200
5 – 20
10 Data)
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Chemical Up to (µg/L) DW Limit (µg/L) Trichloroethylene (TCE) 3,200 5.0
Tetrachloroethylene (PCE) 380 5.0
1,1-‐Dichloroethane (1,1-‐DCA) 31 5.0
1,1,-‐Dichloroethene (1,1-‐DCE) 290 6.0
1,2-‐Dichloroethane (1,2-‐DCA) 2.7 0.5
Carbon Tetrachloride (CTC) 8.1 0.5
cis-‐1,2-‐DCE 48 6.0
Methylene Chloride 17 5.0 2007 Quarterly Monitoring – 86 monitoring wells
Closing Remarks
Treatment Op?ons
Current Treatment
Groundwater Contamina?on
San Fernando Basin
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Chemical Up to (µg/L) DW Limit (µg/L) 1,4-‐Dioxane 25 1.0 (NL)
Nitrosodimethylamine (NDMA) 120 ng/L 10 ng/L (NL)
Hexavalent Chromium (Cr6) 420 10
Perchlorate 45 6
1,2,3-‐Trichloropropane (TCP) 88 ng/L 5 ng/L (NL) 2007 Quarterly Monitoring – 86 monitoring wells Focused Feasibility Study, 2009
Closing Remarks
Treatment Op?ons
Current Treatment
Groundwater Contamina?on
San Fernando Basin
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2015 1990 1998 2002 2009
115
58 49
31 30
Closing Remarks
Treatment Op?ons
Current Treatment
Groundwater Contamina?on
San Fernando Basin
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u Monthly, quarterly, or annually from various extrac?on, monitoring, and produc?on wells for:
u Vola?le Organic Chemicals (VOCs)
u Hexavalent Chromium (Cr6)
u 1,4-‐Dioxane
u 1,2,3-‐Trichloropropane (TCP)
u NDMA
u Annual monitoring for metals (incl. Cr), NDMA, perchlorate, nitrate, and others
Closing Remarks
Treatment Op?ons
Current Treatment
Groundwater Contamina?on
San Fernando Basin
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210
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North Hollywood Operable Unit (NHOU)
Burbank Operable Unit (BOU)
Glendale Operable Unit (GOU)
Pollock Operable Unit (POU)
Tujunga Wellfield Treatment
Closing Remarks
Treatment Op?ons
Current Treatment
Groundwater Contamina?on
San Fernando Basin
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u Goal: Remedia?on & hydraulic plume containment
u Designed purely for VOC removal
Treatment Systems Current Capacity
(gpm) North Hollywood 2,000 Burbank 9,000 Glendale 5,000 Pollock 3,000
Closing Remarks
Treatment Op?ons
Current Treatment
Groundwater Contamina?on
San Fernando Basin
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u Began opera?on in 1989
u Designed primarily for hydraulic containment of plume
u 2,000 gpm treatment facility designed to remove VOCs (mainly TCE & PCE), but operates at ~750 gpm
u U?lizes air-‐stripping with off-‐gas GAC treatment
u Treated water is injected into LA’s drinking water system
u However, recent discovery of other contaminants (e.g., Cr6 & 1,4-‐dioxane) have led to the shutdown of some wells feeding the facility
Closing Remarks
Treatment Op?ons
Current Treatment
Groundwater Contamina?on
San Fernando Basin
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u Shut down of wells caused concern over lack of plume containment as originally planned
u Interim ROD (EPA, 2009), amended in 2014
u NHOU will be modified to remove Cr6 and 1,4-‐Dioxane from two impacted well
u Expand the facility to ~3,600 gpm for improved plume containment
u Design is underway (may already be completed)
u The 2014 amendment allows for the water to be re-‐injected into the ground instead of delivering it to LADWP’s system
Closing Remarks
Treatment Op?ons
Current Treatment
Groundwater Contamina?on
San Fernando Basin
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Cost Deliver Water to
LADWP Re-‐Inject into Groundwater
Capital Cost $37M $66M Annual O&M Cost $6.4M/yr $6.2M/yr NPV for 30 yrs of Opera?on $108M $134M Amendment to the 2009 Interim Record of Decision (2014)
Closing Remarks
Treatment Op?ons
Current Treatment
Groundwater Contamina?on
San Fernando Basin
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EPA Goals u Remedia?on
u Plume Containment
Water System Goals u Maximize use of GW
u Management of water sources (e.g., stormwater capture & storage in basin)
Closing Remarks
Treatment Op?ons
Current Treatment
Groundwater Contamina?on
San Fernando Basin
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u Removing known contaminants from San Fernando Groundwater is technically feasible
u Treatment technologies are available, and are in place now at some loca?ons
u The challenges (aside from legal) are related to: u Residuals
u Cost
u Others
Closing Remarks
Treatment Op?ons
Current Treatment
Groundwater Contamina?on
San Fernando Basin
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Contaminant Treatment OpHons VOCs Air-‐Stripping
GAC Adsorp?on Advanced Oxida?on
Hexavalent Chromium Ion-‐Exchange Reduc?on/Coagula?on/Filtra?on
1,2,3-‐TCP GAC Adsorp?on 1,4-‐Dioxane Advanced Oxida?on NDMA UV Irradia?on
Closing Remarks
Treatment Op?ons
Current Treatment
Groundwater Contamina?on
San Fernando Basin
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Treatment Residual Air-‐Stripping & GAC Adsorp?on
Spent GAC loaded with VOCs that requires disposal as Haz Waste
Ion-‐Exchange (Cr6) Salt Brine containing high Cr and other metals disposed as Haz. Waste
Coag./Filt. (Cr6) Dry sludge containing high Cr and other metals disposed as Haz. Waste
Closing Remarks
Treatment Op?ons
Current Treatment
Groundwater Contamina?on
San Fernando Basin
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Value Capital Cost (2015 – 2023)(1) $600M – $900M Annual O&M Cost (2023)(1) $50M/yr Total Annual Cost(2) $100M/yr – $125M/yr (1) Liu, AGWA Conference, 2014 (2) Capital cost amor6zed over 30 years @ 7% interest
Closing Remarks
Treatment Op?ons
Current Treatment
Groundwater Contamina?on
San Fernando Basin
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u In recent years, EPA has been studying Vapor Intrusion Pathways from contaminated groundwater
u The idea is that VOC vapors could migrate up from contaminated groundwater to indoor environment
u The 2013 Five-‐Year Review for Area 2 (Glendale OU) notes that the level of contamina?on is above the default threshold for concern over vapor intrusion, especially considering the high popula?on density
u This issue will be addressed further in the next 5-‐year review
Closing Remarks
Treatment Op?ons
Current Treatment
Groundwater Contamina?on
San Fernando Basin
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u The California MCL for Cr(VI) in drinking water is now 10 µg/L
u However, the total Cr MCL in California con?nues to be 50 µg/L
u The remedia?on goals con?nue to separate the two
u However, they are not independent
u Total Cr = Cr(VI) + Cr(III)
u Therefore, a Cr(III) concentra?on in treated water from remedia?on systems can s?ll be as high as 50 µg/L
u This is problema?c for a drinking water system
Closing Remarks
Treatment Op?ons
Current Treatment
Groundwater Contamina?on
San Fernando Basin
39 Closing Remarks
Treatment Op?ons
Current Treatment
Groundwater Contamina?on
San Fernando Basin
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u In the world of analy?cal chemistry, you can only find what you’re looking for
u Prior to 1998, no one knew about perchlorate, and so no one analyzed for it
u Prior to 2000, no one knew about NDMA, and thus no one analyzed for it
u The same for 1,4-‐dioxane and 1,2,3-‐TCP
u I hope no one believes that we know all the chemicals in the groundwater
Closing Remarks
Treatment Op?ons
Current Treatment
Groundwater Contamina?on
San Fernando Basin
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u No current remedy should be considered final
u Barriers should be included to provide some protec?on against contaminants we don’t currently know about
u Space should be provided for adding future treatment systems for the contaminant(s) we discover next
u Do we need to maintain blending of the final treated water with uncontaminated water at all ?mes?
u No easy answer… but we need to ask the ques?on!
Closing Remarks
Treatment Op?ons
Current Treatment
Groundwater Contamina?on
San Fernando Basin
Issam Najm [email protected]
