20240729_POM_Plan

PUMPING OPERATION AND MAINTENANCE PLAN
SAND MINE DEWATERING WITH SEDIMENTATION POND
Operator: Tripp Bros., Inc., Bobby J.Tripp, President
4158 Norris Store Road, PO Box 128,Ayden, NC 28513
Job Location: Alvin Road Mine,SR 1562 Alvin Road,Grimesland, NC 27837
County: Pitt County
Prepared by: Ken Elliott,consulting
Date: July 13,2024
This plan defines responsibilities for operating,inspecting,and maintaining equipment and structures
used for dewatering the Alvin Road Sand Mine safely,and that dewatering will not degrade or negatively
impact any wetlands or waters of the state.
Description and Current State of the Alvin Road Mine Site and Mining Application:
The Alvin Road Mine is a proposed 14.69-acre sand mine excavation to be operated by Bobby J.Tripp,
president of Tripp Bros., Inc.,applicant,in a 41.80-acre permit area,of which 31.10 acres will be
affected,located off SR 1562 Alvin Road, in Grimesland, NC in Pitt County.The permit area is on
cultivated,sandy land at 10-ft elevation,owned by the applicant. The site is located 1.4 miles west of
Chicod Creek,which flows eastward from there 1.6 miles to Tar River,thence 44 miles to Pamlico Sound.
Mr.Tripp is now applying for a mining permit with the NCDEQ Division of Energy, Mineral and Land
Resources to construct the sand mine and begin operation in August or September 2024. An NPDES
General Permit application for dewatering is being submitted to NCDEQ and registration for water usage
has been submitted to the Division of Water Resources. A Stormwater Pollution Prevention Plan is
under development and will be implemented upon approval of the discharge permit application.
Sand Mine Dewatering:
It will be necessary to dewater the pond as it is being excavated to allow excavating equipment to enter
the area safely and efficiently remove sand from the pond bottom. This will allow for full permitted
depth of excavation of the pond and proper reclamation of the edges of the pond. It is the intention of
the operator to only dewater the excavation as needed,which will not entail full-time dewatering.
For excavation purposes,dewatering will occur intermittently, upon need, 12 hours per day, 15 days per
month,at a rate of 96,000 gallons per day. The operator plans to excavate approximately 25,000 cubic
yards of sand at a time while dewatering and stockpile it for later usage. Once the stockpiled sand is
depleted,the operator will dewater the excavation again and remove another quantity of sand.
Mine dewatering wastewater will be treated before release to the Waters of the State. Use of a
sedimentation pond separate from the excavated mine is a traditional and effective means to remove
sediment from wastewater generated during mine dewatering operations.

Sedimentation Pond Construction and Overflow Discharge:
The operator plans to excavate a 1.73-acre sedimentation pond,approximately 20 feet deep, located
185 feet north of the main excavation area for dewatering the main excavation. The sediment pond will
have a 4-ft tall by 22-ft wide berm constructed around the pond perimeter to help maintain dewatering
volume. The pond berms will have a minimum of 1.5 feet of freeboard between the water surface and
the top of the sediment pond bank. The sediment pond will be located adjacent to an existing blue-line-
stream ditch which flows eastward 520 feet to wetlands draining to Chicod Creek.
Sediment pond water level will be controlled by a half-pipe flash-board water height control device
installed in the southwest corner of the sediment pond berm.The control structure will allow water to
flow across the flash boards into a 85-ft long x 24-in wide PVC discharge pipe running southward
through the sediment pond berm to an outlet discharging to a 20-foot-long riprap-protected apron in
the blue-line-stream ditch,leading 550 feet to wetlands. From there,discharge water will drain 1.4
miles to Chicod Creek.
Dewatering Procedure:
The operator will install an 8-inch dewatering pump between the main excavation and sediment pond at
the northeast corner of the excavation. Discharged water from the dewatering pump will enter the
sediment pond at its southeast corner and will overflow through a constructed half-pipe flash board
water height control device discharge point located on the southwest corner of the sediment pond.The
discharge point will release clear water through the water-height control device into the existing blue-
line-stream discharge ditch draining to wetlands and Chicod Creek.
Water will be pumped from the excavated pond to the sediment pond by the 8-in gasoline-powered
transfer pump operating at idle speed,approximately 1200 rpm. Estimated maximum flow from the
pump will be 8,000 gallons/hour,operating 12 hours per day,0.096-mgd. It is the intention of the
applicant to lower the water level in the excavation approximately 20-25 feet below normal
groundwater level as needed.
Time and distance will allow all sedimentation to occur to acceptable levels before the overflow water
reaches its outfall and then the waters of the State. Water will flow a minimum of 360 feet to reach the
overflow point which will give enough surface area to allow sufficient sedimentation to occur. There will
be a minimum of 1.5 feet of freeboard between the water surface in the sediment pond and the top of
the sediment pond bank. Stormwater drainage will be unable to enter the sediment area and damage
the sediment pond rates,due to the height of a surrounding 4-ft tall sediment pond berm.
Wetlands Protection:
Removing water from the excavation using a sedimentation pond with overflow is a valid dewatering
method for this size excavation. The pond can be dewatered quickly,and water removed from the pond
will be used to uniformly hydrate adjacent wetlands.

Once dewatered,excavation activity will be focused on removing sand from the pond as quickly as
possible to shorten the periods of dewatering. This will allow the groundwater level in the pond to
return to normal as soon as possible to lessen possible impacts to adjacent wetlands,once dewatering
ceases.
Groundwater Control:
Groundwater levels are not expected to be impacted in areas outside of the immediate excavated
dewatering area. Groundwater levels are expected to remain stable despite dewatering of the
excavation. The excavation site is located 500 feet south of the 1500-acre Tar River wetlands area,
which serves to drain and hydrate the area adjacent to the proposed permit area.
Groundwater level depletion is not expected to affect any neighboring groundwater wells.The closest
residences to excavation are located 620 feet from the proposed excavation,with others further.
Properties along Alvin Road are served by the Pitt County Water System.
Sedimentation and Erosion Control:
The operator will maintain 50-ft wide unexcavated buffers on the north and south sides of excavation
activity,and 100-ft wide unexcavated buffers on the east and west sides. The operator will maintain 50-
ft undisturbed riparian buffers on each side of two blue-line-streams crossing the permit area. Existing
access road crossings of the blue-line-streams will be protected by silt fence along each side of the ditch
crossing.
All erosion and sedimentation will remain inside the permit area.The operator will construct and
maintain a 26-ft wide x 6-ft tall grass-covered sand berm around the perimeter of the current affected
area of the excavation during all phases of operation, inside the unexcavated buffer.Stormwater falling
inside the active mining area will be directed to drain into the excavation by diversion drains.
Maintaining the Dewatering Equipment and Erosion Control Measures:
Inspections and maintenance are required to obtain the intended function of safely dewatering the sand
mine, and to maintain the life of any nearby wetlands or waters of the State. Items to inspect and
maintain during the anticipated 10-year life of the mine dewatering permit are:
• Inspect embankments, berms and appurtenant structures,and repair as needed.
• Monitor overflow ditches for damage or stoppage from beaver activity, repair as needed.
• Repair any damage to vegetated areas or berms with compacted earth fill, reshaping,sodding,
reseeding,and mulching as needed.
• Promptly repair all leaks in delivery facilities by replacing valves,fittings,gaskets,and worn or
damaged parts.
• Maintain all screens,filters,valves,timers,and other electrical and mechanical equipment in
good operating condition,following manufacturer's recommendations.

Monitoring the Dewatering Process and Effects of Dewatering:
Analytical and qualitative monitoring of mine dewatering wastewater will be in accordance with the
NCG020000 permit,as follows:
• The Alvin Road Mine sedimentation pond will discharge mine dewatering wastewater into
wetlands draining to Chicod Creek,classified as C;NSW,and to Tar River,classified as B;NSW.
• Per requirements of the NPDES permit,discharge water will be sampled quarterly and analyzed
for pH,Total Suspended Solids(TSS),turbidity,and salinity. Samples with benchmark
exceedances will require the operator to increase sampling, per NPDES permit, until sample
results are cleared.
• All excavated ponds in the Alvin Road Mine excavation area will be inspected daily by the
operator to identify any abnormal conditions.
• All berms and erosion control structures will be inspected for damage monthly and within 24
hours after every storm event greater than 1.5 inches,and all structures will be repaired
immediately.
• Special inspections will be conducted immediately following severe storms,vandalism,and
other significant events.
• Dewatering process will be inspected daily during periods of dewatering the excavation.
• Rain gauge data will be collected by monitoring local rain gauge data monthly and after each
rain event.
Wetlands Monitoring:
Wetlands are located westward of the proposed Alvin Road Mine site. Level 1 wetlands landscape
assessment by US Fish &Wildlife Service indicate one type of wetlands near the parcel in question:
• PFO1C—Palustrine deciduous forested seasonally flooded, 150 ft east and 38S ft north of
excavation boundary.
• PFO1A—Palustrine deciduous forested temporarily flooded,580 ft north of excavation
boundary.
Level 2 wetlands assessment has not been performed on the site. Discharge ditches and the
sedimentation pond will serve as hydration devices to help maintain normal groundwater levels.
Operator will monitor drainage ditches weekly to always ensure presence of water in the ditch.
Records
Data will be collected as follows:
• Visual monitoring of adjacent wetlands and farmland for potential dehydration during mining or
dewatering activities will take place weekly. Solutions to any degradation caused by any mining
activity will include alteration of dewatering process. DWQ will be consulted as needed;
alterations to process will be recorded.

• Elliott Consulting will maintain the following records in a permanent file at the Elliott Consulting
office at PO Box 112,202 Elliott Road,Aydlett, NC 27916: a record of all significant actions
taken; as-built drawings; permits; analytical results from sampling; and related material. Copies
of all inspections, monitoring reports and lab analyses shall be provided to NCDWQ on a regular
basis and as requested.
• Stormwater Pollution Prevention Plan and other pertinent documents and records will be
available online for inspection at www.tripp-sp3.com.
BMP Conditions
• The permittee will utilize best management practices to ensure that dewatering the Alvin Road
Mine excavation will not degrade or negatively impact any wetlands or waters of the State.
BMP's will include:
o All berms and erosion control and sedimentation control structures will be inspected for
damages monthly and within 24 hours after every storm event greater than 1.5 inches,
and all structures will be repaired immediately.
o A paved construction entrance will be maintained at intersection of the mine access
road and SR 1562 Alvin Road.
o Operator will maintain riprap outfall protection on the overflow drainage ditch
downstream of sediment pond.
o Groundcover will be established on all sections of the permit area when not in use by
mining activities.
Signed,
Ken Elliott
for Tripp Bros., Inc., Operator
Alvin Road Mine, Grimesland, NC
July 13, 2024