dams and impoundments

Dams and ImpoundmentsDams and Impoundments

2010 Industry Training Workshop

Jim Kline DEP- Bureau of Oil and Gas Management

Objectives:Objectives:

• Typical ScenariosTypical Scenarios

• Worksheet for Permitting of Marcellus Shale Pits and DamsWorksheet for Permitting of Marcellus Shale Pits and Dams

• What permits (if any) might be neededWhat permits (if any) might be needed

• Construction Standards for ImpoundmentsConstruction Standards for Impoundments

• Groundwater MonitoringGroundwater Monitoring

• Current impoundment trendsCurrent impoundment trends

Typical ScenariosTypical Scenarios

• Dams on a watercourse• Dams not on a watercourse

• Dams on a watercourse

Dams on a WatercourseDams on a Watercourse

Greater than 100 acre drainage area, OR

Greater than 15’ maximum depth, OR

Greater than 50 acre-feet maximum storage

Drainage areaDrainage area

The drainage area is the total surface The drainage area is the total surface area upstream of a point on a area upstream of a point on a stream, where the water from rain or stream, where the water from rain or snowmelt which is not absorbed into snowmelt which is not absorbed into the ground flows over the ground the ground flows over the ground surface back into the stream to surface back into the stream to finally reach that point on the finally reach that point on the stream. stream.

Drainage areaDrainage area

What the heck is an Acre What the heck is an Acre Foot?Foot?

A measurement associated with a larger A measurement associated with a larger volume, in this case water storage. It is volume, in this case water storage. It is the amount of water required to cover an the amount of water required to cover an acre one foot deep.acre one foot deep.

An acre foot is equivalent to 325,851 An acre foot is equivalent to 325,851 gallons of watergallons of water

50 acre feet is equal to 16,292,550 gallons 50 acre feet is equal to 16,292,550 gallons of waterof water

MAXIMUM DEPTHMAXIMUM DEPTH

Dmax > 15 ft

The bottom of the Pit or The bottom of the Pit or Impoundment must be Impoundment must be

constructed at least 20” above constructed at least 20” above the seasonal high groundwater the seasonal high groundwater

table.table.

(ref Ch 78.56 (a) (4) (iii))(ref Ch 78.56 (a) (4) (iii))

Dams on a WatercourseDams on a Watercourse

Greater than 100 acre drainage area OR

Greater than 15’ maximum depth OR


If this is the scenario, then a Dam Safety Permit is required from DEP’s Division of Dam Safety

Dams not on a watercourse

Greater than 15’ maximum depth

AND


Worksheet for Worksheet for Permitting of Permitting of

Marcellus Shale Pits Marcellus Shale Pits and Damsand Dams

Worksheet for Permitting of Marcellus Worksheet for Permitting of Marcellus

Shale Pits and DamsShale Pits and Dams

1. Fresh or frac water impoundment pits or dams at a well location must meet the requirements of PA Code Chapter 78.56 – 78.63 and the Design, Construction and Maintenance Standards for Pits and Dam Embankments Associated with Impoundments for Oil and Gas Wells. Plans must include an acknowledgement that these pits and impoundment dams will meet the standards. Proceed to Section 6 and Section 8 and submit to the appropriate Department Regional Oil and Gas Program Office.

Worksheet for Permitting of Marcellus Worksheet for Permitting of Marcellus

Shale Pits and DamsShale Pits and Dams 2.2. On-stream intake dams. (Dams/weirs constructed for On-stream intake dams. (Dams/weirs constructed for

water withdrawal from streams. Height and storage are water withdrawal from streams. Height and storage are typically minimal.)typically minimal.)

2.A2.A A dam/weir will be constructed on-stream solely for the A dam/weir will be constructed on-stream solely for the purpose of water withdrawals: purpose of water withdrawals:

No:No: Proceed to Section 3 or Section 4 as appropriateProceed to Section 3 or Section 4 as appropriate..

Yes: Answer the following questions:Yes: Answer the following questions:

Worksheet for Permitting of Worksheet for Permitting of Marcellus Shale Pits and DamsMarcellus Shale Pits and Dams

Is maximum depth greater than 15 feet?Is maximum depth greater than 15 feet? Yes No Yes No

Is maximum storage volume greater than 50 acre-feet? Yes NoIs maximum storage volume greater than 50 acre-feet? Yes No

Is contributory drainage area greater than 100 acres? Yes NoIs contributory drainage area greater than 100 acres? Yes No

If the answer to all three of these questions is no, an If the answer to all three of these questions is no, an Environmental Environmental Assessment approval is requiredAssessment approval is required from the Department’s Dam Safety from the Department’s Dam Safety Program. Program. Please submit form 3140-PM-WE0002, Please submit form 3140-PM-WE0002, Environmental Assessment Environmental Assessment Information Sheet Information Sheet and information required on that form’s checklist to the and information required on that form’s checklist to the Department’s Dam Safety Office. Any excavation of the stream, wetland or Department’s Dam Safety Office. Any excavation of the stream, wetland or floodway upstream of this intake dam to expand storage volume will require floodway upstream of this intake dam to expand storage volume will require a Water Obstruction and Encroachment Permit from the appropriate a Water Obstruction and Encroachment Permit from the appropriate Department Regional Office.Department Regional Office.


If the answer to any one of these questions is yes, a Dam Permit If the answer to any one of these questions is yes, a Dam Permit may be required from the Department’s Dam Safety Program. may be required from the Department’s Dam Safety Program. Answer the following questions:Answer the following questions:

Is height of dam/weir above streambed elevation greater than 3.0 Is height of dam/weir above streambed elevation greater than 3.0 feet?feet? Yes Yes No No

Is width of stream at the dam site greater than 50 feet? Yes NoIs width of stream at the dam site greater than 50 feet? Yes No

Is this stream a wild trout stream designated by the PA Fish and Is this stream a wild trout stream designated by the PA Fish and Boat Commission? Boat Commission? Yes Yes No No


If the answer to all three of these questions is no, the Dam Permit If the answer to all three of these questions is no, the Dam Permit for this dam is waived pursuant to §105.12(a)(1) of the Department’s for this dam is waived pursuant to §105.12(a)(1) of the Department’s regulations. Contact the Department’s Dam Safety Program for regulations. Contact the Department’s Dam Safety Program for information requirements necessary for adding to Pennsylvania’s information requirements necessary for adding to Pennsylvania’s Dam Inventory.Dam Inventory.

If the answer to any one of these questions is yes, a Dam Permit is If the answer to any one of these questions is yes, a Dam Permit is required from the Department’s Dam Safety Program. Please required from the Department’s Dam Safety Program. Please complete form 3140-PM-WE0001, “complete form 3140-PM-WE0001, “Application for a Dam Permit”, Application for a Dam Permit”, and information required on that form’s checklist to the and information required on that form’s checklist to the Department’s Dam Safety Office. Utilize the Department’s Dam Safety Office. Utilize the Design,Design, Construction Construction and Maintenance Standards for Pits and Dam Embankments and Maintenance Standards for Pits and Dam Embankments Associated with Impoundments for Oil and Gas Wells Associated with Impoundments for Oil and Gas Wells to develop to develop plans and specificationsplans and specifications..


3.3. Centralized fresh water impoundments.Centralized fresh water impoundments.

3.A3.A A dam embankment will be constructed for the A dam embankment will be constructed for the purpose of storing fresh water for the drilling or purpose of storing fresh water for the drilling or fracing at fracing at more than one well location:more than one well location:

No: Fresh water will be impounded in a pit. Proceed to No: Fresh water will be impounded in a pit. Proceed to SectionSection 7 7 for additional information requirements.for additional information requirements.

Yes: Provide the following depth and volume information Yes: Provide the following depth and volume information and proceed to and proceed to Section 3.B.Section 3.B.


Maximum depth of water that could be impounded by the earthfill dam.Maximum depth of water that could be impounded by the earthfill dam. See Exhibit 1.See Exhibit 1. Feet. Feet.

(Measure from the inside toe-of-slope of dam to top-of-dam embankment).(Measure from the inside toe-of-slope of dam to top-of-dam embankment).

Maximum storage volume of water that could be impounded by the earthfill Maximum storage volume of water that could be impounded by the earthfill dam. dam. See Exhibit 1.See Exhibit 1. acre-feet acre-feet

(Measure from the inside toe-of-slope of dam to top-of-dam embankment).(Measure from the inside toe-of-slope of dam to top-of-dam embankment).

Drainage area to the earthfill dam, if located on-stream, then proceed to Drainage area to the earthfill dam, if located on-stream, then proceed to SectionSection 3.B3.B.. Acres. Acres.

If located off-stream, proceed to If located off-stream, proceed to SectionSection 3.C.3.C.


3.B3.B If the dam embankment used to impound fresh water If the dam embankment used to impound fresh water is is located on a watercourselocated on a watercourse, complete the following:, complete the following:

Is maximum depth greater than 15 feet?Is maximum depth greater than 15 feet? Yes Yes No No


Is contributory drainage area greater than 100 acres?Is contributory drainage area greater than 100 acres? Yes No Yes No


If the answer to any one of these questions is yes, a Dam Permit is If the answer to any one of these questions is yes, a Dam Permit is required from the Department’s Dam Safety Program. Please required from the Department’s Dam Safety Program. Please submit form 3140-PM-WE0001, “submit form 3140-PM-WE0001, “Application for a Dam Permit”, Application for a Dam Permit”, and and information required on that form’s checklist to the Department’s information required on that form’s checklist to the Department’s Dam Safety Office.Dam Safety Office.


If the answer to all three of these questions is no, an If the answer to all three of these questions is no, an Environmental Assessment approval is required from the Environmental Assessment approval is required from the Department’s Dam Safety Program. Please submit form Department’s Dam Safety Program. Please submit form 3140-PM-WE002, 3140-PM-WE002, Environmental Assessment Environmental Assessment Information and information required on that form’s Information and information required on that form’s checklist to the checklist to the Department’s Dam Safety Office. Any Department’s Dam Safety Office. Any excavation of the stream, wetland or floodway upstream excavation of the stream, wetland or floodway upstream of this intake dam to expand storage volume will require of this intake dam to expand storage volume will require a Water Obstruction and Encroachment Permit from the a Water Obstruction and Encroachment Permit from the appropriate Department Regional Office.appropriate Department Regional Office.


3.C3.C If the dam embankment used to impound fresh water is If the dam embankment used to impound fresh water is notnot located on a watercourselocated on a watercourse, complete the following: , complete the following:

Is the dam located in a FEMA (Federal Emergency Management Is the dam located in a FEMA (Federal Emergency Management Agency) designated floodway?Agency) designated floodway? Yes Yes No No

If the answer is yes, a Dam Permit may be required from the If the answer is yes, a Dam Permit may be required from the Department’s Dam Safety Program and/or a restudy of the FEMA Department’s Dam Safety Program and/or a restudy of the FEMA Floodway may be required to assess the impacts of the dam on the Floodway may be required to assess the impacts of the dam on the floodway. Coordination will also be required with the local floodway. Coordination will also be required with the local municipality to assure that they remain eligible for the National municipality to assure that they remain eligible for the National Flood Insurance Program. Please submit information required in Flood Insurance Program. Please submit information required in Section 6 Section 6 to the Department’s Dam Safety Office for the to the Department’s Dam Safety Office for the determination of the need for a permit or other approvals.determination of the need for a permit or other approvals.


If this answer is no, continue with the following questions: If this answer is no, continue with the following questions:

Is maximum depth greater than 15 feet?Is maximum depth greater than 15 feet? Yes Yes No No


If the answer to both of these questions is yes, a Dam Permit is If the answer to both of these questions is yes, a Dam Permit is required from the Department’s Dam Safety Program. Please required from the Department’s Dam Safety Program. Please submit form 3140-PM-WE0001, “submit form 3140-PM-WE0001, “Application for a Dam Permit”, Application for a Dam Permit”, and and information required on that form’s checklist to the Department’s information required on that form’s checklist to the Department’s Dam Safety Office.Dam Safety Office.


If the answer to either or both of the above questions is no If the answer to either or both of the above questions is no and the dam directly impacts a wetland, an Environmental and the dam directly impacts a wetland, an Environmental Assessment approval is required from the Department’s Assessment approval is required from the Department’s Dam Safety Program. Please submit form 3140-PM-Dam Safety Program. Please submit form 3140-PM-WE0002 WE0002 Environmental Assessment Information Sheet and Environmental Assessment Information Sheet and information required on that form’s checklist to the information required on that form’s checklist to the Department’s Dam Safety Office. Utilize the Department’s Dam Safety Office. Utilize the Design,Design, Construction and Maintenance Standards for Pits and Dam Construction and Maintenance Standards for Pits and Dam Embankments Associated with Impoundments for Oil and Embankments Associated with Impoundments for Oil and Gas Wells Gas Wells to develop plans and specificationsto develop plans and specifications..

If the answer to either or both of the above questions is no If the answer to either or both of the above questions is no and the dam does not impact a wetland, no dam permit is and the dam does not impact a wetland, no dam permit is required.required.


4. 4. Centralized frac water storage (Fluids other than fresh water Centralized frac water storage (Fluids other than fresh water (e.g. drilling or fracing fluids)):(e.g. drilling or fracing fluids)):

4.A4.A If a dam embankment will be constructed to create this If a dam embankment will be constructed to create this storage facility, proceed to storage facility, proceed to SectionSection 4.B. 4.B.

If the storage facility is to be an excavated lined pit, the facility must If the storage facility is to be an excavated lined pit, the facility must meet the requirements of PA Code Chapter 78.56 – 78.63 and the meet the requirements of PA Code Chapter 78.56 – 78.63 and the Design,Design, Construction and Maintenance Standards for Pits and Dam Construction and Maintenance Standards for Pits and Dam Embankments Associated with Impoundments for Oil and Gas Embankments Associated with Impoundments for Oil and Gas Wells.Wells. Plans must include an acknowledgement that this pit will Plans must include an acknowledgement that this pit will meet the standards. Complete information requirements in meet the standards. Complete information requirements in Section Section 66 and and Section 8Section 8 and submit to the appropriate Department Regional and submit to the appropriate Department Regional Oil and Gas Program Office.Oil and Gas Program Office.


4.B4.B A dam embankment will be constructed to impound frac A dam embankment will be constructed to impound frac water and the following describes this impoundment:water and the following describes this impoundment:

Length Length ft. ft.

Width Width ft. ft.

Maximum potential depth of frac water Maximum potential depth of frac water ft. ft.

Storage Volume ____ ac.-ft.Storage Volume ____ ac.-ft.


4.C4.C This dam embankment to be constructed to impound frac This dam embankment to be constructed to impound frac water water is: (Please check appropriate box below) is: (Please check appropriate box below)

a. Located on a watercourse.a. Located on a watercourse.

b. Located off-stream, but impacts a wetland.b. Located off-stream, but impacts a wetland.

c. Located off-stream and in FEMA (Federal Emergency c. Located off-stream and in FEMA (Federal Emergency Management Agency) Floodway.Management Agency) Floodway.

d. Located off-stream, storage volume exceeds 50 acre feet d. Located off-stream, storage volume exceeds 50 acre feet andand depth of impoundment exceeds 15 feet as noted in depth of impoundment exceeds 15 feet as noted in 4.B4.B above.above.

e. Located off-stream, storage volume is less than 50 acre feet e. Located off-stream, storage volume is less than 50 acre feet oror depth of impoundment is less than 15 feet as noted in depth of impoundment is less than 15 feet as noted in 4.B4.B above.above.


If any of the boxes a through d are checked, a Dam Permit is If any of the boxes a through d are checked, a Dam Permit is required from the Department’s Dam Safety Program. Please required from the Department’s Dam Safety Program. Please submit Form 3140-PM-WE0001, “submit Form 3140-PM-WE0001, “Application for a Dam Permit”, Application for a Dam Permit”, and and information required on that form’s checklist to the Department’s information required on that form’s checklist to the Department’s Dam Safety Office. Also, submit information requirements in Dam Safety Office. Also, submit information requirements in Section 8Section 8. Utilize the . Utilize the Design,Design, Construction and Maintenance Construction and Maintenance Standards for Pits and Dam Embankments Associated with Standards for Pits and Dam Embankments Associated with Impoundments for Oil and Gas Wells Impoundments for Oil and Gas Wells to develop plans and to develop plans and specifications.specifications.

If box e, is checked, proceed to If box e, is checked, proceed to SectionSection 55..


5.5. Potential Impacts of Dam FailurePotential Impacts of Dam Failure

Failure of this frac water impoundment dam has the potential to:Failure of this frac water impoundment dam has the potential to:

Impact inhabited structures:Impact inhabited structures: Yes Yes No No

Cause significant property damage:Cause significant property damage: Yes Yes No No

Flood roadways:Flood roadways: Yes Yes No No


If yes to any of the dam failure impact questions, a Dam Permit is If yes to any of the dam failure impact questions, a Dam Permit is required from the Department’s Dam Safety Program. Please required from the Department’s Dam Safety Program. Please submit Form 3140-PM-WE0001, “submit Form 3140-PM-WE0001, “Application for a Dam Permit”, Application for a Dam Permit”, and and information required on that form’s checklist to the Department’s information required on that form’s checklist to the Department’s Dam Safety Office. Also, submit information requirements in Dam Safety Office. Also, submit information requirements in Section 8Section 8. Utilize the . Utilize the Design,Design, Construction and Maintenance Construction and Maintenance Standards for Pits and Dam Embankments Associated with Standards for Pits and Dam Embankments Associated with Impoundments for Oil and Gas Wells Impoundments for Oil and Gas Wells to develop plans and to develop plans and specifications. specifications.


If no to all of the questions above, a Dam Permit from the If no to all of the questions above, a Dam Permit from the Department’s Regional Bureau of Oil and Gas Management office is Department’s Regional Bureau of Oil and Gas Management office is required. Please submit form 5500-PM-OG0084, “required. Please submit form 5500-PM-OG0084, “Application For AApplication For A Dam Permit For A Centralized Impoundment Dam for Marcellus Dam Permit For A Centralized Impoundment Dam for Marcellus Shale Gas Wells”, Shale Gas Wells”, and information required on that form’s checklist and information required on that form’s checklist to the Department’s Regional Bureau of Oil and Gas Management to the Department’s Regional Bureau of Oil and Gas Management Office.Office. Also, complete information requirements in Also, complete information requirements in Section 8Section 8. . Utilize the Utilize the Design,Design, Construction and Maintenance Standards for Pits Construction and Maintenance Standards for Pits and Dam Embankments Associated with Impoundments for Oil and and Dam Embankments Associated with Impoundments for Oil and Gas Wells Gas Wells to develop plans and specifications.to develop plans and specifications.


6.6. Attach a copy of USGS 7½ minute quadrangle map Attach a copy of USGS 7½ minute quadrangle map showing the location of the pit or dam and attach a site plan showing the location of the pit or dam and attach a site plan and typical cross-sections of the pit or dam.and typical cross-sections of the pit or dam.


7. If a pit is proposed to store fresh water, no Dam Permit is required. 7. If a pit is proposed to store fresh water, no Dam Permit is required. However, if the pit is located on a watercourse, in the floodway of a However, if the pit is located on a watercourse, in the floodway of a watercourse, or in a wetland, a Water Obstruction and Encroachments watercourse, or in a wetland, a Water Obstruction and Encroachments Permit is required. Permit is required. Please submit Form 3930-PM-WE0036 Please submit Form 3930-PM-WE0036 Joint Permit Application Joint Permit Application and and information on that form’s checklist to the Department’s appropriate information on that form’s checklist to the Department’s appropriate Regional Office, Permitting and Technical Services Section.Regional Office, Permitting and Technical Services Section.

8.8. Attach site restoration plan for all frac water impoundment pits and Attach site restoration plan for all frac water impoundment pits and dams. Frac water impoundments pits or dam sites must be restored dams. Frac water impoundments pits or dam sites must be restored within nine months after completion of the last well that was serviced within nine months after completion of the last well that was serviced by the impoundment.by the impoundment.

Centralized ImpoundmentsCentralized Impoundments

Well Site Pits and ImpoundmentsWell Site Pits and Impoundments

Pits and impoundments located on the drilling Pits and impoundments located on the drilling site will be authorized by the Oil and Gas Well site will be authorized by the Oil and Gas Well Permit. These impoundments must follow the Permit. These impoundments must follow the Construction Standards.Construction Standards.

Construction Standards for Construction Standards for Dams and EmbankmentsDams and Embankments

Associated with Pits and Associated with Pits and Impoundments for Oil and Impoundments for Oil and

Gas WellsGas Wells

Construction StandardsConstruction Standards

The operator may use alternate construction standards The operator may use alternate construction standards if they meet or exceed the Department’s Construction if they meet or exceed the Department’s Construction Standards, if they are developed, sealed and certified Standards, if they are developed, sealed and certified by a professional engineer registered in Pennsylvania; by a professional engineer registered in Pennsylvania; and if they are approved through a Dam P Application and if they are approved through a Dam P Application process through the Department’s Division of Dam process through the Department’s Division of Dam Safety prior to commencement of construction.Safety prior to commencement of construction.

Construction StandardsConstruction Standards

Soils to be used for dam embankment Soils to be used for dam embankment construction must be classified in accordance construction must be classified in accordance with ASTMD-2487 (Unified Soils Classification). with ASTMD-2487 (Unified Soils Classification). A minimum of three samples must be classified.A minimum of three samples must be classified.

Soils acceptable for dam embankment Soils acceptable for dam embankment construction are limited to GC, GM, SC, SM, CL construction are limited to GC, GM, SC, SM, CL or ML. Soils must contain a minimum of 20% of or ML. Soils must contain a minimum of 20% of Plus No. 200 sieve materials.Plus No. 200 sieve materials.

Gradation Gradation SheetSheet

GC- Clayey gravels

GM- Silty gravels

SC- Clayey sands

SM- Silty sands

CL- Inorganic clays low to medium plasticity

ML- Inorganic silts and fine sand, slight plasticity

Site PreparationSite Preparation

Foundation of dam embankment must be stripped and Foundation of dam embankment must be stripped and grubbed to a depth of two feet prior to any placement & grubbed to a depth of two feet prior to any placement & compaction of earthfill.compaction of earthfill.

Any springs encountered in the foundation area should Any springs encountered in the foundation area should be drained to the outside/downstream toe of the be drained to the outside/downstream toe of the embankment with a drain section two foot by two foot in embankment with a drain section two foot by two foot in dimension consisting of PennDOT Type A sand, dimension consisting of PennDOT Type A sand, compacted by hand tamper. No geotextiles to be used compacted by hand tamper. No geotextiles to be used around sand. The last three feet of this drain at the around sand. The last three feet of this drain at the outside/downstream slope should be AASHTO #8 outside/downstream slope should be AASHTO #8 material.material.

CompactionCompaction

All compaction for embankments must be done with a All compaction for embankments must be done with a sheepsfoot or pad roller. sheepsfoot or pad roller.

Loose lift thickness must be 9” or less. Loose lift thickness must be 9” or less.

Maximum particle size is 6”.Maximum particle size is 6”.

A minimum of 5 passes of the compaction equipment over the A minimum of 5 passes of the compaction equipment over the entire surface of each lift is required.entire surface of each lift is required.

Compaction to visible non-movement of the embankment Compaction to visible non-movement of the embankment material is required.material is required.

Soil Placement and CompactionSoil Placement and Compaction

Pad RollersPad Rollers

Design CriteriaDesign Criteria

Minimum embankment top width of 12’ is required.Minimum embankment top width of 12’ is required.

Minimum inside & outside sideslopes of 3H:1V are Minimum inside & outside sideslopes of 3H:1V are required. required.

All exposed embankment slopes must be limed, All exposed embankment slopes must be limed, fertilized, seeded and mulched. Permanent vegetative fertilized, seeded and mulched. Permanent vegetative ground covering compliance with PA Code Chapter ground covering compliance with PA Code Chapter 102.22 must be established upon completion of dam 102.22 must be established upon completion of dam construction.construction.

2’ of lined freeboard must be maintained at all times.2’ of lined freeboard must be maintained at all times.

Embankment Top WidthEmbankment Top Width

Minimum 12’Minimum 12’

Take a closer look…..Take a closer look…..

Failure to properly compactFailure to properly compact movement of the embankment movement of the embankment

materialmaterial

Failure to maintain 2 feet of Failure to maintain 2 feet of lined freeboardlined freeboard

Selecting the Correct LinerSelecting the Correct Liner

The Geosynthetic Institute- The Geosynthetic Institute- GM13GM13

A standard specification for High Density Polyethylene Geomembranes

Addresses the amount of recycled or re-worked material allowed in the formulation of the liner (No more than 10%)No Post consumer resins of any type can be added

CH 78 addresses the EPA Method 9090, The Compatibility of Wastes and Liners

CH 78 addresses the minimum CH 78 addresses the minimum thickness of liners used for the thickness of liners used for the

disposal of residual wastes.disposal of residual wastes.

How thick must a liner be for How thick must a liner be for these centralized these centralized impoundments?impoundments?

The large volumes of stored The large volumes of stored liquid and hydrostatic liquid and hydrostatic

pressures creates an increased pressures creates an increased potential for possible failure.potential for possible failure.

Only Only 30 mil30 mil liners are allowed. liners are allowed.

Only a synthetic liner can be Only a synthetic liner can be usedused. . Compacted clays or Compacted clays or earthen materials are not earthen materials are not

allowedallowed

Failed 20 mil liners Failed 20 mil liners (two separate locations)(two separate locations)

Failed 20 mil linerFailed 20 mil liner

Groundwater MonitoringGroundwater Monitoring


An operator shall collect background data An operator shall collect background data prior to the construction of the prior to the construction of the impoundment. This attempt is to establish impoundment. This attempt is to establish baseline background data for the baseline background data for the groundwater where the impoundment is to groundwater where the impoundment is to be constructed. In the event that the be constructed. In the event that the impoundment was already constructed, safe impoundment was already constructed, safe drinking water levels apply.drinking water levels apply.


A groundwater monitoring/protection plan is required for A groundwater monitoring/protection plan is required for all impoundments that will remain longer than 9 months.all impoundments that will remain longer than 9 months.

Applying the Residual Waste Regulations... CH 289 and Applying the Residual Waste Regulations... CH 289 and 299 address the number and placement of monitoring 299 address the number and placement of monitoring wells for these types of impoundments. wells for these types of impoundments.

The well casing standards are also addressed in these The well casing standards are also addressed in these chapters.chapters.

The operator will monitor the groundwater (at a The operator will monitor the groundwater (at a

minimum) on a monthly basis. The operator will also minimum) on a monthly basis. The operator will also maintain this data. The gathered information must be maintain this data. The gathered information must be made available upon DEP request.made available upon DEP request.


The following parameters (at a minimum) The following parameters (at a minimum) must be monitored and tested for:must be monitored and tested for:

pHpH

Specific ConductanceSpecific Conductance

TDS TDS

ChlorideChloride

Sulfates Sulfates


In the event of groundwater In the event of groundwater contamination, the operator must contamination, the operator must notify the appropriate regional DEP notify the appropriate regional DEP office within 24 hours of the incident. office within 24 hours of the incident.


Prior to restoration, the operator must Prior to restoration, the operator must affirm and attest that no contamination affirm and attest that no contamination occurred.occurred.

If contamination occurred, the operator If contamination occurred, the operator must first affirm that the contamination must first affirm that the contamination was mitigated and corrected.was mitigated and corrected.

Immediately following the restoration of Immediately following the restoration of the impoundment, the monitoring wells the impoundment, the monitoring wells then shall be plugged.then shall be plugged.

Leak DetectionLeak DetectionTypically is comparable to a Typically is comparable to a French drain system that is French drain system that is installed between the upper installed between the upper impoundment liner and a impoundment liner and a lower second containment lower second containment liner. A riser pipe is liner. A riser pipe is connected to the drain connected to the drain system allowing an operator system allowing an operator to monitor for the presence to monitor for the presence of water in this zone.of water in this zone.

Typical Problems with this Typical Problems with this system are ground water system are ground water intrusion and liner failures intrusion and liner failures or punctures.or punctures.

Use of a subbaseUse of a subbase

As previously mentioned, the subgrade should be well compacted and present a surface free of rocks, stones or anything that might puncture the liner.

There should be no abrupt grade changes, voids or surface discontinuities.

Use of a subbaseUse of a subbase In the event that it is In the event that it is

impractical to remove all of impractical to remove all of the rocks from the subgrade, the rocks from the subgrade, at least six inches of screened at least six inches of screened soil or other acceptable soil or other acceptable material must be used to material must be used to provide a protective cushionprovide a protective cushion

A cushioning geotextile is also A cushioning geotextile is also acceptable and recommended.acceptable and recommended.

In the event that protrusions In the event that protrusions can not be removed or can not be removed or protected against, the protected against, the impoundment is likely toimpoundment is likely toFAIL. FAIL.

ImpoundmentImpoundment ( (under constructionunder construction))

3 to 1 inside and outside 3 to 1 inside and outside slopesslopes

min 12’ embankment top min 12’ embankment top widthwidth

proper compactionproper compaction

maximum particle size is maximum particle size is less than 6”less than 6”

screened soil as a subbasescreened soil as a subbase

Do not utilize organic matter as a Do not utilize organic matter as a subbasesubbase

The Decomposition of organic matter The Decomposition of organic matter produces gas and results in the produces gas and results in the potential for the liner to burst or potential for the liner to burst or

rupture!rupture!

VegetationVegetationDam embankments must be maintained Dam embankments must be maintained with a grassy vegetative cover, free of with a grassy vegetative cover, free of brush and trees.brush and trees.

Reasonable Reasonable protection from protection from

unauthorized acts unauthorized acts of third parties of third parties

Ch 78.56 (a) (3).Ch 78.56 (a) (3).

RestorationRestoration

Prior to the site restoration, all of the liquid fraction of waste must be disposed of at an approved treatment facility or reused at another well site.

If the remaining residual waste meets CH 78 regulations relating to: the Characteristics of toxicity, the contaminants in the leachate from the wastedoes not exceed 50 times the safe drinking water level and the concentration ofcontaminants in the leachate from the waste does not exceed 50 times the primary maximum contaminant level…

then the waste can be disposed of in accordance with CH 78 on-site.

RestorationRestoration

If the remaining solid waste fraction was generated from only one well site, then the residual solid waste and liner can be disposed of in accordance with CH 78.

If the residual waste does not meet CH 78 requirements, then the residual waste must be hauled off-site and then disposed of at an approved disposal facility.

If the residual solid waste was generated from MULTIPLE well sites, then this waste and liner must be removed and hauled to an approved landfill. This portion of waste can not be land applied or encapsulated on site.

Jim KlineJim KlineMineral Resources Program Specialist Mineral Resources Program Specialist Division of Resource Management & Well Division of Resource Management & Well

DevelopmentDevelopmentDEP - Bureau of Oil & Gas ManagementDEP - Bureau of Oil & Gas Management

814-472-1903814-472-1903

[email protected]@state.pa.us

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