3.8  Cape Fear River Subbasin 03-06-21
Includes the Northeast Cape Fear River and Barlow Branch
Municipalities: Mount Olive

LCFRP Station Code (DWQ#):  NC403 (94)
DWQ/UNCW ambient monitoring site(s):  NC403
Waterbody:  Northeast Cape Fear River
Location:  NC Hwy 403, on the borders of Wayne and Duplin County
Lat/Lon:  N 35.17838    W 77.98028 (NC403)  

Use Support Ratings, from NCDENR, DWQ (Cape Fear River Basinwide Water Quality Plan, July 2000):
Freshwater Streams
Fully Supporting:                   69.3 mi.
Partially Supporting:             0.0 mi.
Not Supporting:                     4.3 mi.
Not Rated:                              6.8 mi.

        Significant dischargers in this subbasin are Mount Olive Pickle Company and the Town of Mount Olive.  DWQ biological assessment sampling resulted in no impaired rating for streams in this subbasin.

        Portions of the Northeast Cape Fear River and Barlow Branch were identified as impaired in the 1996 Basinwide Water Quality Plan.  The discharge from Mount Olive Pickle Company was the cause of impairment. Chloride levels exceeded the water quality limit in 48% of the samples from 1993 to July 1996, at Northeast Cape Fear River at SR 1937 approximately 2.7 miles from discharge source.  The ambient water quality station was relocated approximately 5.1 miles downstream in 1996 to the NC403 site.  The ambient station data at NC 403 has not indicated high chloride levels.  Currently the Northeast Cape Fear River (3.3 miles from source to SR 1937) and Barlow Branch (1 mile) are not supporting (NS).  (NCDENR, DWQ, Cape Fear River Basinwide Water Quality Plan, July 2000) 

        The Mount Olive Pickle Company discharges chlorides above permitted levels into Barlow Branch before it joins the Northeast Cape Fear River.  The Mount Olive Pickle Company was given a variance from the state surface water quality standard for chloride (230mg/L) in 1996.  They have met the requirements of the variance to date, and have reduced water usage and salt usage.  (NCDENR, DWQ, Cape Fear River Basinwide Water Quality Plan, July 2000) 

UNC-Wilmington – Center for Marine Science, LCFRP
Station Name:  NC403
Data collection:  June 1997 – present
Sampling relevance:  Below Mount Olive Pickle Plant  
 

 
                       NC403 - slow moving creek

        The NC403 site was found nonsupporting (NS) by UNCW for dissolved oxygen concentrations, with levels below the North Carolina State Standard of 5.0 mg/L in eight of the twelve sampled months (66% of all samples).  Concentrations were below the NC Swampwater Standard of 4.0 mg/L in seven of the twelve months (58% of samples).  The lowest levels were found in August 2001, with dissolved oxygen concentrations of 0.2 mg/L.  The mean for July 2001 thru June 2002 was 2.9 mg/L (Figure 3.8.1). 

        For biological standards, NC403 was found fully supporting (FS) for both chlorophyll a and fecal coliform bacteria.  Samples did not exceed the 40 mg/L standard for chlorophyll a concentrations or the 200 CFU/100 mL standard for human contact waters for fecal coliform bacteria more than 10% of the time.

        NC403 was found to be fully supporting (FS) for turbidity, with samples not exceeding the standard of 50 NTU.  The mean turbidity level was 3 NTU for 2001-2002.

        UNCW researchers are concerned that elevated nutrient levels are periodically found at this site.  Nitrate-N concentrations >200 mg/L occurred several times in 2000-2001, levels that can cause algal blooms.  High total phosphorus (TP) concentrations occur at times, which UNCW scientists find can stimulate increased biochemical oxygen demand (BOD) and lead to lower dissolved oxygen levels (Mallin et al. 2002).

Figure 3.8.1  Dissolved oxygen concentrations (mg/L) for NC403.  The line shows
the NC State Standard for dissolved oxygen of 5.0 mg/L and the dashed line shows
the NC State Standard for swampwater of 4.0 mg/L.