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Home My WebLink About20220241 Ver 1_Wetland Monitoring Plan_20230125AkMartin Marietta Belgrade Quarry Bender Pit Wetland Monitoring Plan January 25, 2023 1.0 Project Description Martin Marietta Materials, Inc. (MMM) proposes to expand existing mining operations at the Belgrade Quarry by excavating a new limestone quarry pit known as the Bender Pit. Pit construction will be conducted using large excavators, drag lines and/or front-end loaders, and large off -road trucks. All discharged water from the pits will meet the water quality standards set forth by the existing NPDES Industrial General Permit Number NCG020005 issued by NC Department of Environment and Natural Resources' (NCDENR) Division of Water Resources. The proposed 92.5-acre Bender Pit is located south of the existing pit on the east side of the White Oak River. This proposed pit is separated from the current pit and plant area by a wetland system, which encircles the proposed pit. MMM is proposing two road crossings in order to provide adequate safe access to the new pit area. The northern crossing crosses two wetland areas and would impact 0.45 acre of wetland. It is located to align with an existing established road, which travels to the plant area. This proposed product haul road would also impact 0.18 acre of wetland associated with the expansion and upgrade of an existing crossing as shown on the map at the north-eastern tip of the proposed pit. A second proposed haul road for overburden is aligned to allow the safest and most direct travel for hauling overburden material to the existing mined -out southern end of the current pit. This proposed crossing would be constructed in the narrowest area of the wetland system, which divides the two pits, while still allowing direct travel. Impacts associated with this road total 106 LF of stream and 0.9 acre of wetland. The proposed Bender pit is comprised of mostly upland areas with 5 wetland fingers which extend into the pit area. These impact areas have been studied for geological resources and the proposed wetlands impacts will allow access to those areas, as well as to mine ore in upland areas. Wetland impacts from the pit total 7.43 acres. Wetland areas surrounding the pit will have a minimum 50ft buffer. Between this 50ft buffer and the pit, a road/berm will be constructed to allow travel around the mine and to remedy any possible flooding of the pit. Inside of this berm, overburden will slope down to the rock surface which will be mined. Total wetland impacts for the project including roads and pit equal 8.96 acres. 2.0 Existing Conditions The project site is located adjacent to an existing and active limestone quarry known as the Belgrade Quarry. The 1,605-acre Quarry site is in the White Oak River Basin (03020301), and includes the old mine pit, the current mine pit, the facility infrastructure, and the Project Area. The Quarry operation has been active in its current pit configuration since 1988. The main infrastructure for the Quarry has been constructed for the existing pit operations and would also be used to continue mining in the proposed new pit areas in the Project Area. The Bender Pit area is comprised of active farm fields and mixed pine forestland with some hardwoods such as sweetgum and red maple. Soils on the site consist of fine sands, such as Pactolus, Johns and Autryville in the upland marine terraces and soils such as Muckalee loam in the wetlands and floodplain areas. A wetland delineation was conducted on the site and a Preliminary Jurisdictional Determination with a signed survey was approved on May 28, 2014. In 2019, this determination was field checked, and portions were re -delineated by MMM wetland staff. The re -delineation was reviewed in the field by Corps of Engineers staff on 7/9/2020 and 12/15/2020. 3.0 Purpose of Monitoring MMM is proposing to excavate a limestone quarry pit as shown on the attached Figure 1. This pit will be de -watered in order to extract the limestone deposit. USACE has expressed concerns about potential indirect impacts to nearby wetlands. MMM proposes to monitor these wetlands in order to document the level of impacts, if any, and to compensate for any indirect impacts documented to occur. 4.0 Monitoring Guidelines MMM will install monitoring wells using the ERDC 2005 WRAP guidelines in the locations shown on Figure 1. Monitoring wells will be placed in transects at 50ft and 100ft from the wetland boundary. Placing the monitoring wells in these areas will ensure that any negative impacts from mining will be detected. The wells may be monitored using Onset HOBO Cellular monitoring systems similar to those depicted in the photo shown on Figure 2. MMM may use other updated monitoring technology depending on what is available at the time of installation. The gauges will be programmed to take daily water level measurements and for the measurement data to be saved remotely. 5.0 Reporting Gauges will be programmed such that hydrologic data at each monitoring gauge station will be collected daily, with automatic data uploading from each station to a remote database. A monitoring report will be prepared at the end of each year for regulatory agency review and will be submitted by March 31s1 of the following year. This annual monitoring report will provide shallow groundwater data presented in summary tables and graphs. Rainfall data will also be provided. 6.0 Monitoring Duration, Success Criteria and Regulatory Determination To establish a baseline, monitoring will begin at least one growing season prior to any mining in the Bender Pit. Growing season, as recommended by the Corps, is considered to be February 1 through November 30. Monitoring Reports will be submitted by March 31st of each year. Once mining has commenced, monitoring will continue until mining in Pit B has ceased or a determination is received from the Corps of Engineers that monitoring is no longer required. MMM may request that individual wells or transects be removed from monitoring if mining adjacent to them has ceased. The wetland type of the area monitored could be described as a Riverine Swamp Forest and Bottomland Hardwood Forest. As such, NCWAM describes Riverine Swamp Forest as seasonally to semi -permanently inundated and Bottomland Hardwood Forest as intermittently to seasonally inundated. Referencing Table 5 of the 1987 Corps of Engineers Wetland Delineation Manual, seasonally inundated wetlands should exhibit wetland hydrology for greater than 12.5% of the growing season in most years (50% probability of occurrence). Therefore, this metric along with comparison to baseline and rainfall data will be used to determine if indirect adverse impacts have occurred. If occurrence of indirect adverse impacts to wetlands is documented, the Corps will communicate with the applicant regarding the impacts documented and any additional efforts necessary to further assess the extent of such impacts. If mitigation is necessary to address documented indirect adverse impacts to wetland, the applicant will establish a mitigation plan at that time. Figure 1 Belgrade Quarry Wetland Monitoring Map Drawn by: Thomas Brown 1/25/2023 For Permitting Purposes Only Locations Are Approximate Legend O Proposed Wetland Monitoring Locations Road Crossings Proposed Bender Pit Wetland_Impacts Wetland Boundary A �F�Martin Vcrietta Wetland Monitoring Wells to be placed in transects at 50ft and 100ft from wetland boundary. Monitoring locations are approximate. Some field relocation of the transects may be necessary, but the 50ft and 100ft distances from the wetland boundary will be maintained. erial Imagery 640 320 0 640 Feet Figure 2.