7607_GreatOakMSWLF_LDS_Flood_ActionPlan_DIN28461_20170915

1
Chao, Ming-tai
From:Workman, John <[e-mail]>
Sent:Friday, September 15, 2017 1:24 PM
To:Chao, Ming-tai; Patrone, John
Cc:McFeeley, Michael; Moore, Daniel; Carroll, Shawn; Barnes, Gene(Atlanta GA); Lamb,
Steve ([e-mail])
Subject:Great Oak Cell 1 Secondary Collection system
Attachments:Leachate Control System Inspection Form Rev 02 - Sept 2017.pdf
Ming, this email is to confirm our discussion the other day.

The landfill experienced a heavy rainfall on September 1st and the secondary collection alarm on the sump panel
activated. Upon inspection we discovered a significant amount of muddy water in the sump.

Site personnel inspected the perimeter of the cell and discovered the threaded cap removed from the leak detection
clean-out riser. The riser is adjacent to the perimeter stormwater ditch and muddy water was flowing into the leak
detection system. The cap was immediately replaced. We haven’t determined why the cap was removed or was
dislodged.

The influx of stormwater into the secondary system created a calculated flow rate of approximately 211
gal/acre/day. This exceeds the permit Action Leakage Rate (ALR) of 182 gal/acre/day. This was a temporary condition
and recent liquid level measurements in the sump indicate the flows are quickly returning to pre-rain levels. On 9/12
the flow was down to 31 gal/acre/day compared to the pre-event 4-5 gal/acre/day.

The influx of muddy water raises concern about the integrity of the secondary system. We propose the following steps
to verify the secondary collection system will function as designed:
• Jet clean the collection pipe and sump. A contractor is scheduled for the week of September 18th and
will be supervised by SCS Engineers.
• Inspect the collection pipe and sump with a downhole camera. Additional cleaning will be conducted if
SCS determines it necessary.
• Inspect the riser-pipe boot to verify the welds and seal are intact.
• Submit a brief report on the results of the investigation.

In addition, we plan to implement the following changes to prevent this problem from reoccurring.
• Weld a 3 ft. extension onto the leak detection clean-out riser. This will raise the pipe entrance well above the
perimeter ditch flow level.
• Secure the cap to the riser with either a bolt or screws.
• Add weekly riser inspection to our Leachate Control System Inspection program. Visual integrity of the cap and
riser inspection has been added to the attached inspection form.

We are disappointed this event occurred and believe the above actions will help assure the integrity of the secondary
collection system. We hope the above action items address your main concerns. Please call me with any questions about
our proposed plan.

Waste Management
1850 Parkway Place
Suite 600
Marietta, GA 30067
2
770-590-3308

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Is tank exterior free of leaks, corrosion,
or other maintenance deficiencies?
[Yes or No*]
Is tank overfill protection equipment in
good working order? [Yes or No*]
Has accumulated water been removed
from secondary containment?
[Yes or No*]**
Tank leachate level gauge reading
[Feet]
Pump station flow meter reading
[Gallons]
Are visable elements of leachate force
main and associated plumbing in good
working order?
[Yes or No*]***
Are upper and lower leachate line cell-to-
tank manholes dry based on visual
inspection? [Yes or No*]
Approximate amount of rain since last
inspection? [Inches]
Primary Sump Totalizer Reading for
Cell 1A/B [Gallons]
Secondary Sump Totalizer Reading for
Cell 1A/B [Gallons]
Estimated Secondary Liner Leakage****
[Gallons/Acre/Day]
Is Cell 1A primary liner clean-out riser
securly capped? [Yes or No*]
Is Cell 1A secondary liner clean-out riser
securly capped? [Yes or No*]
Is Cell 1B primary liner clean-out riser
securly capped? [Yes or No*]
Is Cell 1B secondary liner clean-out riser
securly capped? [Yes or No*]
Notes:
*
**
***
****
Form Revised: September 15, 2017. This form may be replaced or combined with other operational inspection forms as long as the referenced regulatory information is collected. Leachate Sump Control PanelDate:
Inspected by:
WASTE MANAGEMENT OF CAROLINAS, INC. - GREAT OAK LANDFILL
Weekly Leachate Control System Inspection
Reference: 15A NCAC 13B .1680 Leachate Storage Requirements
Leachate Storage TankCell-to-Tank PlumbingLeachate Sump Clean-Out Riser PipesIf No, provide an explanation on Page 2 and/or attach a maintenance plan.
Removal of any accumulated precipitation must be initiated within 24 hours or when 10 percent of the storage capacity is reached, whichever occurs first.
If leakage is discovered during inspection, a verbal and written notification followed by an action plan shall be submitted to the SWS in a reasonable time frame.
Estimated Secondary Liner Leakage is calculated by subtracting the previous weeks totalizer reading from the current weekly total; divided by the total secondary liner acreage; divided by the
number of elapsed days since the previous measurement. Leakage rates in excess of 182 gallons per acre per day require Response Action Plan implementation per facility's DEQ Permit to Operate.
Cell 1A has 8.3 acres of secondary liner, and Cell 1B has 7.0 acres for a total of 15.3 acres.
Date
WASTE MANAGEMENT OF CAROLINAS, INC. - GREAT OAK LANDFILL
Weekly Leachate Control System Inspection
Reference: 15A NCAC 13B .1680 Leachate Storage Requirements
Page 2 - Comments
1
Chao, Ming-tai
From:Patrone, John
Sent:Tuesday, September 12, 2017 12:00 PM
To:Chao, Ming-tai
Subject:FW: Great Oak Landfill - Stormwater in Leak Detection Liner - September 1, 2017
Attachments:Photo of Cell 1B Secondary Liner Cleanout.pdf
FYI

John Patrone, Environmental Senior Specialist
Field Operations Branch, Solid Waste Section
NCDENR, Division of Waste Management
PO Box 16202
High Point, NC 27261
Phone: [phone]
http://portal.ncdenr.org/web/wm/sw
[e-mail]

Email correspondence to and from this address is subject to the North Carolina Public Records Law and
may be disclosed to third parties unless the content is exempt by statute or other regulation.

From: Moore, Daniel [mailto:[e-mail]]
Sent: Friday, September 8, 2017 2:31 PM
To: Patrone, John <[e-mail]>
Cc: McFeeley, Michael <[e-mail]>; Workman, John <[e-mail]>; Darragh, Terry
<[e-mail]>
Subject: Great Oak Landfill - Stormwater in Leak Detection Liner - September 1, 2017

John,

As we discussed this morning, on the afternoon/evening of September 1, 2017, Great Oak Landfill received
over 2 inches of rain in a very short period of time. This heavy rain event resulted in overtopping of a
perimeter stormwater diversion ditch on the northern side of Cell 1B (location shown on the plan
below). An adjacent secondary/leak detection liner cleanout pipe was flooded and approximately 34,000
gallons of stormwater entered the system. The secondary/leak detection liner flow totalizer was monitored
on the morning of September 1, and recorded a value of 8,065 gallons. Following the event, on September
6, flow appeared to have largely stabilized and the totalizer read 42,075 gallons. Some additional drainage
into the sump is anticipated.

The perimeter stormwater ditch in the area of the secondary cleanout pipe has been regraded to preclude
the over-accumulation of stormwater, and any potential for future flooding of the liner cleanout pipe (see
attached photos). The threaded cap for the cleanout pipe has been reattached and secured. We speculate
that the cap may not have been sufficiently tightened during late 2016 construction activities, and
inadvertently came off prior to or during the referenced storm. An extension to the cleanout is planned, to
assure that no future incidents of this nature occur.

If you require any additional documentation related to this event please let me know; and, as always, we
appreciate your assistance.

2

Dan Moore
Environmental Protection Manager
[e-mail]

Waste Management – North Carolina/South Carolina
3303 N Glenn Ave
Winston-Salem, NC 27105
Cell [phone]

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