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Home My WebLink About20221434 Ver 1_Monitoring Report_20231115Monitoring Report NC-EXP-0002 Country Line Creek Pipeline Protection Project Caswell County NCDEQ DWR Permit #20221434 USACE Permit #SAW-2022-02217 1It Monitoring Event —October 2023 �y0 GAS LINE � \ � --MARKER CID: _ �� srj�j �� TOP 14 ' STEEL .STEED 408 � PIPE = 4 71. 21 ' 1009 \0, GASrL11VE f MARKER 1 r Prepared for North Carolina Department Environmental Quality Division of Water Resources NC-EXP-0002 October 2023 Post -Construction Monitoring Project; NCDWR Permit # 20221434 Project Summary The NC-EXP-0002 pipeline protection project (36.471869,-79.197029 WGS84) was implemented in June/July 2023 to protect Kinder Morgan's existing 14-inch active pipeline (14W-14) and stabilize an unnamed tributary to Country Line Creek in Caswell County, North Carolina. The unnamed tributary to Country Line Creek is a perennial stream that flows south to north and crosses the Kinder Morgan ROW perpendicularly. There are approximately 32 linear feet of stream within the existing ROW. PROFILE AT APPRDXIMATE CENTERLINE OF CREEPS The implemented design protects the pipeline and minimize future erosion by utilizing step pools to reduce stream velocity while staying within the limits of the existing ROW. The design placed the upstream mat edge downstream of the existing bedrock step and with the placement of sturdy fill from the edge of the visible bedrock downstream to the pipeline the existing step feature was transitioned to an in -channel pool. The graded aggregate base and articulating mat was shaped as it exited the pool, over the pipeline, and immediately downstream which directs low or normal flow to exit the pool in one area. The mat immediately downstream of the pipeline mimics the current bedrock step and water drops into the rip rap energy dissipator. On either side of the rip rap dissipator, large stones were embedded in the slopes. The NCDEQ DWR permit (#20221434) specified visual monitoring at a minimum of quarterly for the first year or two bankfull events, and then annually until the site is stable and vegetation is successful to ensure the stability and water quality of the stream and downstream waters. NC-EXP-0002 October 2023 Post -Construction Monitoring Project; NCDWR Permit # 20221434 Post Construction Review Photos of the workspace in the ROW were taken after project completion. No photos were taken solely of the upstream and downstream segments outside of the ROW. Photo points with an associated direction have been designated for each segment using coordinates and a figure prepared to allow for consistent photos for comparison between monitoring events (Figure 1). Monitoring Event #1 —October 2023 On October 3, 2023, a pedestrian survey was conducted to visually evaluate areas within and around the stream channel for undermining or failure of the structures, stream bank or in channel erosion, and dying/dead vegetation, including upstream of the workspace (-25 feet), within the workspace (ROW), and downstream of the workspace (-125 feet, until after stream channel turns). The work areas outside the stream channel, associated with the stabilization effort, access, and laydown areas, were also assessed to evaluate stream stabilization after the construction activities. A general photo was taken of the implemented pipeline protection project (Figure 2). Flags were placed at monitoring points to aid consistency of future monitoring efforts. Observations are summarized in Table 1, while photos taken at the designated photo points are shown in Table 2. Finally, a trail camera was installed, upstream segment of the pipeline crossing, on the right bank with a stream gauge installed on the opposite bank. Field indicators, including the uppermost scour line and back of a point bar, were assessed to determine the bankfull elevation upstream of the pipeline crossing. The cross -sectional area of the stream at the bankfull elevation was found to be approximately 10 ftz, which falls within the expected range for a rural Piedmont stream given a drainage area of approximately 0.43 miz (NCSU Extension, 2000). The bankfull elevation was marked on the stream gauge, so stream water levels can be visually compared against bankfull elevation via the trail camera. Kinder Morgan will create a GeoHazard alert for precipitation events for the project site. When an alert is issued, Jacobs staff will remotely activate the camera to observe, via photo or video, whether bankfull conditions have been reached. Table 3 includes photos taken during setup and with the trail camera. Generally, during the October 2023 field monitoring event, stream morphology (right banks, left banks, in -stream conditions), vegetation, and the structure appear stable, with no visual evidence of inappropriate erosion, sediment accumulation, or dead/dying vegetation, and no signs of structure failure (Tables 1 and 2). Amphibians and fish were noted to be utilizing pools immediately upstream of the structure, as well as downstream of the structure, with appropriate levels of leaf litter accumulation. Downstream of the structure, the stream's existing condition is deeply incised, with near -vertical streambanks and undercutting in various areas, but there was no visual evidence of recent erosion. However, in the non -stream work area above the left bank in the non -stream work area near the pipeline crossing, several small erosional pits, less than 1 ft2 in area and less than 6-inches in depth, were observed under matting (Figure 3). The erosional pits, which are above likely maximum stream water elevations, appear related to surface runoff from the relatively steep hillside that comprises the left bank in this area. Additionally, seeded grass along the left bank in this area was observed at approximately 25% coverage, versus approximately 50% coverage on the right bank. Continued monitoring of these areas is recommended. If the erosional pits progress or vegetation does not sufficiently establish, corrective action can be taken. NC-EXP-0002 October 2023 Post -Construction Monitoring Project; NCDWR Permit # 20221434 JhU Figure 1 - Photo Point Locations Figure 2. General Photograph of Pipeline Protection Project in unnamed tributary to Country Line Creek. NC-EXP-0002 October 2023 Post -Construction Monitoring Project; NCDWR Permit # 20221434 Figure 4 - Additional Photos of Non -stream work area with several small erosional pits (approximately 1 ft2 and less than 6" deep) high on left bank References North Carolina State University Extension (NCSU Extension). 2000. Finding Bankfull Stage in North Carolina Streams (AG-590-03). NC-EXP-0002 October 2023 Post -Construction Monitoring Project; NCDWR Permit # 20221434 Table 1 — Monitoring Visit #1 — Summary of Observations and Monitoring Stations Segment Comments Corrective Action Needed Upstream • Right bank condition stable None at this time • Left bank condition stable • In -stream condition stable • No evidence of inappropriate erosion, sediment accumulation, or dead/dying vegetation Fish observed ROW — Pool 1 • Right bank condition stable None at this time • Left bank condition stable • In -stream condition stable • No evidence of inappropriate erosion, sediment accumulation, or dead/dying vegetation • No evidence of structure failure • Amphibians inhabiting the pool ROW — Pipeline • Right bank condition stable None at this time • Left bank condition stable In -stream condition stable • No evidence of inappropriate erosion, sediment accumulation, or dead/dying vegetation • No evidence of structure failure ROW — Energy Dissipator • Right bank condition stable None at this time • Left bank condition stable • In -stream condition stable • No evidence of inappropriate erosion, sediment accumulation, or dead/dying vegetation • No evidence of structure failure Downstream — Segment 1 • Right bank condition stable • None at this time • Left bank condition stable • In -stream condition stable • No evidence of inappropriate erosion, sediment accumulation, or dead/dying vegetation • Fish observed • Stream's existing condition is deeply incised (up to approximately 5-7 ft), with near -vertical streambanks and undercutting in various areas • Riprap coverage along high energy areas Normal leaf litter accumulation noted in stream channel Downstream — Segment 2 • Right bank condition stable • None at this time • Left bank condition stable • In -stream condition stable • No evidence of inappropriate erosion, sediment accumulation, or dead/dying vegetation • Stream's existing condition is deeply incised, with near -vertical streambanks and undercutting in various areas • Riprap ends near channel turn • Normal leaf litter accumulation noted in stream channel Downstream — Segment 3 • Right bank condition stable None at this time • Left bank condition stable • In -stream condition stable • No evidence of inappropriate erosion, sediment accumulation, or dead/dying vegetation • Stream's existing condition is deeply incised, with near -vertical streambanks and undercutting in various areas • Large sandbar present along left bank • Normal leaf litter accumulation noted in stream channel Non -stream work areas • Matting intact and in good condition • Continue monitoring and, if erosional • Several small erosional pits (approximately 1 ft2 pits progress or increase, implement and less than 6" deep), apparently related to surface runoff improvements surface runoff, high on left bank, which is • Continue monitoring and revegetate as comprised of a steep hill needed • Grass coverage on left bank at approximately 25% versus 50% for right bank • Grass coverage on flat areas at approximately 95% NC-EXP-0002 October 2023 Post -Construction Monitoring Project; NCDWR Permit # 20221434 Table 2 — Monitoring Visit #1 — Photo Documentation of Monitoring Stations Segment Pre Construction July 2023 — Post Construction October 2023 — Monitoring Visit P01: Upstream d w ,.� P02: ROW — Above Pipeline NC-EXP-0002 October 2023 Post -Construction Monitoring Project; NCDWR Permit # 20221434 i tom•' c .�: , •yjH�,' 4 Ai' � '-fu�i AL• a i I / qg j f I h w. .ems x Em�, Ada rr" J f - - / n -4j Xr x__ ti. xd� �. e io�k�r�� r Y G � N,", ✓ll 4 JX?al� P. • ph • • ava i La • Le iO A. t � f `h Z, y J w � w 73 s ;a us, e1fl��i1l�; �w Mrs -r _ -¢ ; xis �"� i5�"•-c- '•-� r. , � �ng,�.s rye _ -- � �..3 r F _ � y�..t: OAK �• A �' ' .:� �a �tv-: ,� �:._a� "�;�� - w '1, .,� �- ,;, �Z�i �'.�"�. •.t�--- -� _t � A .�'� r�#k��A.EE,ii�,_ � •� �- I� i <4r�,t �ri�aly� ,�� r � j�f�'.}'��•,l',Lrr'L,-.�' fi`�. � ' 41 MN % f _.}" al jc,+ �:� 'µ', f-i�-y4- q�.A..!^ I. •�s..;�.� x,,K ti� ,\ 'Y'-RAPR OWL At 11E SOF 27C 1010312023 17:5"-.- ' r �2 � N�l�. r• -�, i i�� I t t °71 � •�j - ! �� },.'; , G ; Y � �, s - R / .;n, �';, rlk., .�` Ity a �' � ` �" �\"tea. 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