Sources of Nitrogen from the Landscape
Waste Water Treatment Plant
Discussion:
There are two types of pollution - point and nonpoint. Point sources of pollution come from distinct points, usually pipes. Waste water treatment plants and factories are example of point source dischargers. The U.S. Environmental Protection Agency regulated point source discharges in 197 under the Clean Water Act. Under this and subsequent legislation, point source dischargers must obtain NPDES permits. These permits limit the kinds and amount of pollutants that can emptied into water resources. These facilities are monitored by state government to check compliance for the permits.
Point sources that discharge nitrogen into the tributaries of the Neuse River or the river itself are listed below. Most of the point sources of nitrogen come from municipal waste water treatment plants. We have listed the largest 30 dischargers. There are another 150 dischargers whom we have lumped all together. These data were provided by the Division of Water Quality, NPDES group.
Dischargers are listed and the amount of nitrogen that they discharged into the river is available for 1995 under the column "Total Nitrogen Discharged." The total amount of nitrogen discharged is calculated by multiplying the actual flow (see column Actual Q 1995) by the nitrogen concentration (Total N Conc (mg/l)).
Load of Nitrogen (lb/yr) = Flow * Nitrogen Concentration
Many processes can happen to water in nitrogen and over distance the amount of nitrogen will decline. To account for the decline in nitrogen over space, transport factors have been provided in the table. The transport factor is a generalized number that relates the nitrogen released at a location to the amount that ends up in the Neuse Estuary. For example, if 100 pounds of nitrogen were released in Raleigh, because the transport factor is 50%, only 50 pounds will end up in the estuary.
The equation is:
N released (lbs) * Transport Factor (%) = N delivered to estuary (lb)The closer the point discharge is to the estuary, the greater the percentage of nitrogen that is delivered to the Neuse.
|
DISCHARGER |
FACILITY |
COUNTY |
TOTAL N DISCHARGED |
N TRANSPORT FACTOR (LB/YR) |
DESIGN Q, 1995 |
ACTUAL Q, 1995 |
TOTAL N CONC (MG/L) 1995 |
|
DHHS - BUTNER, TOWN OF |
JOHN UMSTEAD HOSPITAL WWTP |
Granville |
69,494 |
10% |
3.5 |
2.181792 |
10.5 |
|
DURHAM, CITY OF |
NORTH WTR. RECLAM. FAC |
Durham |
210,560 |
10% |
20 |
8.425233 |
8.2 |
|
HILLSBOROUGH, TOWN OF |
ORANGE WWTP |
Orange |
56,239 |
10% |
3 |
1.20665 |
15.3 |
|
BURLINGTON INDUSTRIES |
WAKE PLANT |
Wake |
163,668 |
50% |
5.00 |
2.195217 |
16.5 |
|
CARY, TOWN OF |
NORTH WWTP |
Wake |
266,603 |
50% |
12.00 |
3.215283 |
27.2 |
|
CLAYTON, TOWN OF |
WWTP |
Johnston |
20,900 |
50% |
1.90 |
0.903475 |
7.6 |
|
JOHNSTON CO. |
CENTRAL JOHNSTON W |
Johnston |
91,314 |
50% |
4.99 |
3.2834 |
9.1 |
|
RALEIGH, CITY OF |
NEUSE RIVER WWTP |
Wake |
1,323,603 |
50% |
60.00 |
32.97455 |
13.2 |
|
WAKE FOREST, TOWN OF |
SMITH CREEK WWTP |
Wake |
11,809 |
50% |
6.00 |
0.694908 |
5.6 |
|
APEX, TOWN OF |
MIDDLE CREEK WWTP |
Wake |
32,838 |
50% |
3.60 |
1.047517 |
10.3 |
|
CARY, TOWN OF |
SOUTH WWTP |
Wake |
266,647 |
50% |
16.00 |
4.839267 |
18.1 |
|
FUQUAY-VARINA, TOWN OF |
WWTP (PROPOSED, AS OF '95) |
Wake |
0 |
50% |
6.0 |
0 |
0 |
|
BENSON, TOWN OF |
SR 1171/S I-95 |
Johnston |
57,564 |
50% |
3.00 |
1.246133 |
15.2 |
|
DUPONT FIBERS |
KINSTON/NC HWY 11 |
Lenoir |
27,533 |
70% |
3.60 |
1.192475 |
7.6 |
|
GOLDSBORO, CITY OF |
WWTP |
Wayne |
370,917 |
70% |
16.80 |
8.455425 |
14.4 |
|
KINSTON, CITY OF |
PEACHTREE WWTP |
Lenoir |
92,382 |
70% |
6.75 |
4.728382 |
6.4 |
|
KINSTON, CITY OF |
NORTHSIDE WWTP |
Lenoir |
48,519 |
70% |
4.50 |
1.606975 |
9.9 |
|
LA GRANGE, TOWN OF |
WWTP |
Lenoir |
12,626 |
70% |
0.75 |
0.468625 |
8.8 |
|
KENLY, TOWN OF |
REGIONAL WWTP |
Johnston |
1,034 |
50% |
0.63 |
0.339283 |
1 |
|
CONTENTNEA SEWERAGE DISTRICT |
WWTP |
Pitt |
60,540 |
50% |
2.85 |
1.50912 |
13.2 |
|
FARMVILLE WWTP, TOWN OF |
WWTP |
Pitt |
38,143 |
50% |
3.50 |
1.638908 |
7.6 |
|
SNOW HILL, TOWN OF |
WWTP |
Greene |
12,678 |
50% |
0.50 |
0.234592 |
17.7 |
|
WILSON, CITY OF |
WWTP |
Wilson |
108,107 |
50% |
14.00 |
8.73705 |
10 |
|
ZEBULON, TOWN OF |
LITTLE CREEK WWTP |
Wake |
18,320 |
50% |
1.85 |
0.8543 |
7 |
|
WEYERHAEUSER CO |
NEW BERN |
Craven |
283,937 |
100% |
32.00 |
21.4933 |
4.3 |
|
CWS SYSTEMS, INC. |
NE CRAVEN UTL |
Craven |
2,440 |
100% |
1.00 |
0.27235 |
2.9 |
|
HAVELOCK, CITY OF |
WWTP |
Craven |
18,524 |
100% |
4.70 |
2.9598 |
13.5 |
|
USMC AIR STATION |
CHERRY POINT |
Craven |
68,900 |
100% |
3.50 |
2.161433 |
10.5 |
|
ALL OTHER DISCHARGERS (~150) |
|
|
149,713 |
|
|
|
~18 |
|
TOTAL |
|
|
4,006,926 |
|
|
|
|