Closure P osure Pathways a thways and d LNAPL P LNAPL Policy - - PDF document

9/4/2019 1

Tom Fox

Colorado Division of Oil and Public Safety (OPS)

Closure P

• sure Pathways a

thways and d LNAPL P LNAPL Policy licy in Col in Colorad ado

CEMS Meeting September 10, 2019

Closure Standards 1988

• 1. Must meet MCLs in groundwater
• 2. Soil contamination must allow #1 to be met
• 3. Recover all LNAPL!!!

3

RBCA

1994: ASTM Guide for Risk-Based Corrective Action Applied at Petroleum Release Sites [ES-38-94] 1995: OSWER Directive 9610.17 encouraged RBCA for USTs

Tier II

• RBCA implemented in 1999 allowed

computer F&T models

• Tier II allows only onsite contamination to

remain in soil and groundwater

5

What was the Problem?

• The majority of open releases were over 10

years old

• Sites over 10 years old were difficult to close

under Tier I and Tier II criteria

• Costs increased as time went on, often with

diminishing returns

• Return on investment (risk reduction) was

seldom considered

9/4/2019 2 2014: Tier III and Tier IV Closure Criteria

Established conditions to allow for

• ffsite contamination to remain in

place based on a risk evaluation.

• Tier III applies to public roadways
• Tier IV applies to private property

7

Closure Tiers Tier III

• A public roadway property boundary is

the only impacted point of exposure

– Fate and transport modeling, empirical data and

• ther lines of evidence must be used to support this
• Remediation has occurred to the

MEP…more on this shortly

Tier IV

• Like Tier III except:

Private property boundaries are impacted The tank system has been removed from the facility

10

Tier III and IV Criteria

• 1. Property boundary is the only impacted

POE (no other receptors)

• 2. Use fate and transport modeling

What about?

• 1. Contaminant removal to the MEP
• 2. Offsite property owners
• 3. Documentation!!

Tier III and IV Implementation Issue 1

280.64 Free product removal. “… owners and operators must remove free product to the maximum extent practicable as determined by the implementing agency…” Resulted in numerous failed and costly remedial implementations with negligible risk reduction

9/4/2019 3

Tier III and IV Implementation Solution

All original CAPs must be designed to meet Tier I or Tier II closure criteria Tier III or Tier IV closure criteria may be considered for releases that cannot achieve Tier I or Tier II closure criteria with consideration given to MEP Consideration given to:

• 1. Proper implementation of past

remedial efforts

• 2. Feasible technologies tried
• 3. Possible future risk reduction
• 4. Access
• 5. Cost

Maximum Extent Practicable

Ineffective

► Manual Bailing ► Absorbent Socks ► Short-term Vacuum

Truck Events

► Passive Skimmers

Tier III and IV Implementation Issue 2

Originally, criteria relied on offsite property

• wner consent:
• Not a deed restriction / covenant
• Included indemnification clause for state
• Owners hired attorneys

Tier III and IV Implementation Solution

Moved to a notification process in January 2016: Notify offsite owners >30 days prior to anticipated closure (“closure under consideration”).

Interesting fact: few people contact OPS with questions/concerns

Big picture: engage with offsite property

• wners ASAP

Property value is NOT a risk consideration.

How to record the location of offsite contamination?

• Deed restrictions / covenants expensive,

time-consuming, and difficult to implement

• Getting owner agreement difficult

Tier III and IV Implementation Issue 3

9/4/2019 4

Tier III and IV Implementation Solution

Fact Sheet created for each Tier III and IV closure

Tier III and IV Implementation Solution

• 1. OPS became a member of Colorado 811
• 2. Area of impact mapped to Colorado 811
• 3. OPS called by construction company to

discuss work and potential exposure

• 4. Email fact sheet to company and publicize

website Benefit: Deal with changes in exposure scenarios when they arise

Tier III and IV Implementation Solution

Closure types since October 2014

Tier I 71% Tier II 18% Tier III 7% Tier IV 4%

Total 1317

Tier III and IV Closures

LNAPL

Colorado adopted ITRC LNAPL principles and recommendations in 2015:

• 1. LNAPL saturation objectives should be addressed

until Tn < 0.8 ft2/day (about 1.5 gpd recovery).

• 2. When recovery is negligible, focus on compositional

concerns to achieve closure.

• 3. Release events can be closed with measurable LNAPL

if the LNAPL recovery is negligible and there are no compositional concerns.

9/4/2019 5

LNAPL Baildown Testing

Follow ASTM E2856 and API Publication 4762. Use ITRC LNAPL Site Management document. Search youtube for “baildown testing”.

• Wells containing >6 inches of LNAPL must be tested.
• Wells containing >2 but <6 inches need special testing

equipment, consult your technical reviewer on need for testing.

• Wells <2 inches likely not recoverable (but OPS may require

testing anyway).

• Data may need to be collected for several hours on a logarithmic
• schedule. Lack of accumulation after several hours likely

indicates Tn < 0.8 ft2/day.

LNAPL Test Interpretation

• 1. Provide the API workbook as an Excel document in

the MRR. Raw data should be on a new, separate tab.

• 2. Be careful to only modify yellow cells.

Some cells are not protected, but must not be modified.

• 3. Collect data long enough…(early data is sand pack

drainage).

• 4. Read the API publication carefully!

Policies Mesh

OPS now allows unrecoverable LNAPL and impacted soil to remain offsite under Tier III and Tier IV.

Allowing LNAPL infers allowing impacted soil. Compositional hazards must still be assessed.

OPS allows a new tank system to be installed on Tier 4 (closed) facilities. Consult with technical reviewer.

• 1. New RCGs adopted for use on July 1, 2019.
• 2. OPS approving more high-resolution site

characterization efforts.

• 3. OPS approving horizontal boring and

Vertebrae™ wells.

• 4. OPS allowing treated purge water disposal
• nsite in pilot programs. Protocol required.
• 5. RBSLs to be reviewed in 2020, newer

toxicology data available.

Other News

• 6. PSTC Policy 29 allows up to $30,000 to

remove a UST system.

• 7. 2019 incentive program waives the $10,000

deductible when system is removed.

• 8. OPS completed Outreach at 5 locations in

the state (June to August 2019).

• 9. Administrative/enforcement support for the

Underground Damage Prevention Safety Commission (811 system). 10.Grants for EV infrastructure available via “Charge Ahead Colorado”

Still Other News

tom.fox@state.co.us