1. Updates 2014 Tar-Pamlico River Basin Plan

2. Basin Plan Updates since March Meeting
General Statute requirements
TMDL goals
NSW Strategy
Estuary status
Action Plan

3. NC General Statute Chapter 143, Article 21
§ B 
The Commission shall develop and implement a basinwide water quality management plan for each of the 17 major river basins in the State. …
Each basinwide water quality management plan shall:
1) Provide that all point sources and nonpoint sources of pollutants jointly share the responsibility of reducing the pollutants…
2) If any of the waters located within the river basin are designated as nutrient sensitive waters, then the basinwide water quality management plan shall establish a goal to reduce the average annual mass load of nutrients…
The Commission shall review and revise its 17 basinwide water quality management plans at least every 10 years …
A basinwide water quality management plan is not a rule and Article 2A of Chapter 150B of the General Statutes does not apply to the development of basinwide water quality management plans. …
Current statute vs proposed integrated quality & quantity statute

4. Trends Analyses Seasonal Kendall Flow-adjusted Concentrations
Flow-normalized Load Estimates
LOADEST- annual load
All waterbodies in the Tar-Pamlico Basin are classified as NSW; a TMDL was done in the early 90’s to target nutrient load reductions to help meet chlorophyll a standards in the estuary.
In order to assess the amount of nutrients being delivered to the estuary from the upper subbasins 3 different types of trend analyses were performed:
-Seasonal and flow-adjusted concentration trends; used to evaluate long term changes in instream concentrations
-Flow-normalized (FN) nutrient loads estimates
-Annual nutrient load using flow weighted average concentrations; used to evaluate which flow interval (low, medium or high) delivers the largest portion of the overall load to the system.
-Long term flow-normalized load estimates; used to evaluate long term changes in nutrient loads associate with different flow regimes and comparing to a benchmark 5 year period ( , except for Chicod Creek which is )
-USGS LOAD ESTimator (LOADEST) annual load; used to estimate an annual load time series and estimated unit area loading time series (using watershed area).

5. TP Load at Grimesland Target = 396,832 lbs/yr
TMDL GOAL: No increase in TP from 1991
Target = 396,832 lbs/yr
Mean 579,692 lbs/yr (LOADEST)
Mean 567,000 lbs/yr (Flow-normalized load)
The TMDL goal for TP is no increase from the 1991 levels. The target is ~400,000lbs/yr. but two different loading estimates show that the current load remains in the high ~500,000lbs/yr. Load assessments (concentration x flow) are highly impacted by precipitation as can be seen in 1999 (hurricane Floyd) and 2003 (unusually wet year).
The LOADEST assessment was used to see the general pattern of loading compared to the 1991 baseline year. The loading only fell below the 1991 baseline during very low flow stream years- 2007, 2008, & 2011.
Flow-normalized TP loading at Grimesland has been consistently lower than the corresponding loading until the period when the load began to increase and has climbed to approximately 30% greater than the load .

6. TN Load at Grimesland Target = 3,000,491 lbs/yr
TMDL GOAL: 30% reduction in TN from 1991
Target = 3,000,491 lbs/yr
Mean 4,593,624 lbs/yr (LOADEST)
Mean 4,700,000 lbs/yr (Flow-normalized Load)
The TMDL goal for TN is a 30% reduction from 1991 levels to meet a target of ~3million lbs/yr. The two different loading estimates both show an average load over 4.5million lbs/yr.
It is important to remember that 1991 was a very dry, low stream flow year which affected the overall loading for both nitrogen and phosphorus. The TN loading only fell below the 30% reduction during the low flow years of 2007, 2008, & 2011
Flow-Normalized (FN) load estimated under long-term average flow conditions were compared to the average load for the period. Five-year moving averages of NOx-N, TKN, TN and TP loads were computed and compared with the corresponding value for the 1991–1995 period.
Results of the FN loading analysis indicates a reduction in NOx-N loading along with an increase in TKN (organic nitrogen) loading. The increase in TKN and TP over the last three to four, five-year periods need further investigation in order to determine the cause of such a drastic shift in the loading of these two nutrient parameters.

7. Seasonal Kendall Flow-Adjusted Concentration Percent Change
Water Quality Constituents mg/L
Upper Tar River
Fishing Creek
Tar River at Tarboro
Chicod Creek
Grimesland
Ammonia (NH3)
* *
- 39 % *
- 41 % *
- 36 % -29%
- 25% *
Nitrate-Nitrite (NOx)
- 80 % *
- 42 % *
- 52 % *
- 26% *
Total Kjeldahl Nitrogen (TKN)
+ 37 % *
+ 60 % +61%
+ 44 % +39%
+ 55% +43%
Total Nitrogen (TN)
+ 32 % +38%
* +21%
+ 12% +24%
Total Phosphorus (TP)
+ 25% *
* +28%
* +31%
* No Trend
Flow-adjusted Concentration Trends with data from , indicate the stations are declining in Nitrate-Nitrite and Ammonia. Total Phosphorus concentrations are only increasing in the Upper Tar River, while TKN concentrations are increasing in all stations except Chicod Creek.
The same trend was run on data from , indicating a few differences, where NH3 & NOx showed significant declines there was no positive or negative trend for these parameters over the past decade. This may indicate that the initial reductions were realized in the 90’s.
Organic Nitrogen is the component of TKN that is increasing and this rise is occurring in the other coastal basins too. Its bioavailability and sources are unknown.
The drainage to the Upper Tar ambient station contributes ~4% of the load to Grimesland (mean TN 300,929lbs/yr. & TP 39,105lbs/yr.). Data indicates a rise in TKN and TP, with TN loads only falling below the 1991 baseline in 4 out of 22 yrs and TP falling below the 1991 baseline 3 out of 22 years.
The area draining to the Fishing Creek station contributes ~8% of the total load to Grimesland (mean TN 160,918lbs/yr. & TP 19,264lbs/yr.). Data indicates a rise in TKN and TN, with TN loads falling below the 1991 baseline in 10 out of 22 yrs and TP falling below the 1991 baseline 9 out of 22 years.
The Tarboro station contributes ~62% of the total load to Grimesland. (mean TN 3,161,774lbs/yr. & TP 393,712lbs/yr.). Data indicates a rise in TKN, with TN loads only falling below the 1991 baseline in 5 out of 22 yrs and TP falling below the 1991 baseline 4 out of 22 years.
The Chicod Creek station drains into the Tar River just upstream the Grimesland ambient station. (mean TN 188,112lbs/yr. & TP 32,110lbs/yr.).

8. NSW Report Trend Analyses Details Review of NSW Strategy & progress
Identifies additional sources
Recommendations & Needs
- Groundwater
- Atmospheric deposition
- BMP efficiencies
- Ag nutrient accounting
- Existing development nutrient loads
- Estuary nutrient cycling
The NSW report is dedicated to the review of the Nutrient Sensitive Water Strategy in which, we recognize the progress made by dischargers, stormwater and agriculture on achieving their 30% reductions. Dischargers(TPBA) have reduced nitrogen loads by over 40% and they have consistently remained below their collective nutrient loading cap and agriculture has had an estimated average 45% nitrogen reduction.
The details of the previously discussed trends analyses are also discussed in this report.
The chapter also reviews potential gaps in the strategy and research needs, including
-groundwater contributions to baseflow
-atmospheric deposition
-BMP efficiencies
-ag nutrient accounting
-land application of waste
-existing development nutrient loads
and estuary nutrient recycling.
Literature reviews and recent discussions with researchers bring up more questions, such as:
Bioavailability of dissolved organic nitrogen
WWTP technology changes results in transfer of nitrogen spp
Septic systems contribution of organic nitrogen
Soil erosion contribution of organic nitrogen
Intensification or application of land use activities are changing
Quality of data used for the original TMDL vs what is available now Anthropogenic vs natural loads of organic nitrogen
We are anticipating the completion of two research studies that may help in identifying nitrogen sources in both the Tar-Pam and Neuse River Basins.

9. 2014 Chlorophyll a Standard Violations
Areas where the chlorophyll a standard (40ug/l) are exceeded in data between (~10K acres), are shown in red. Previous Impairments extended out St.Clair Creek, where the red line crosses the estuary (~32K acres). Pungo Creek ( d) and Pantego Creek ( d) are also exceeding chlorophyll a standards.

10. Upper Station- near Washington
These 2 scatterplots show all of DWR’s Chlorophyll a data, representing conditions in the upper estuary and lower estuary. There continues to be incidences with high chlor a concentrations.
Downstream Station- below Bath Creek, near Aurora

11. Estuary Chlorophyll a Exceedence vs. Flow
The retreat of the chlorophyll a impairment within the estuary is most likely the result of low flow conditions. Our data shows during low flow conditions, the higher chl a concentrations and percent exceedences move into the upstream portion of the estuary. Versus, under normal or elevated flows, the higher chl a concentrations and percent exceedence are pushed downstream.
This is detailed out in the Pamlico Estuary report and further goes into detail about utilization of nitrogen within the estuary.

12. These graphs also show that during assessment timeframes that included drier years the concentration levels and percent exceedance of the 40ug/l standard are higher in the upper estuary than the lower estuary.

13. Action Plan Nutrient Sensitive Water Rules Review Watershed Model
Ag baseline adjustments
Stormwater updates
Watershed Model
Identify data needed for development of model
Watershed Monitoring & Trends
Additional assessment of organic nitrogen
Groundwater Monitoring
Commence groundwater quality monitoring
Stormwater
Agriculture Nutrient Tracking
Atmospheric Deposition
Threatened & Endangered Spp
Aquaculture Facilities
Restoration Prioritization
Action Plan is located at the back of the Summary document, along with additional research needs.
The action plan covers topics that were highlighted in the plan that need additional follow through or implementation with the Division and other agencies. We plan on tracking our progress on each of these topics and can report back yearly on the status.

14. Basin Plan Website
Additional information in the Basin Plan including interactive maps, groundwater, model results, basin geographic features, land cover and population growth are all found under various links on the Basin Plan’s website.

15. Request to proceed to EMC with Final Tar-Pamlico River Basin Plan in Accordance to General Statute B
This is the first integrated water resources basin plan since the merger of the two divisions and look forward to hearing suggestions on improvements as we move forward with the next basin.

17. Extra Estuary Chlorophyll a slides