Environmental Analysis Tools - Environmental Impact Analysis: Process and Methods - page 306

16

Average daily load (kg)
Load under BPT/NPDES

14

12

10

8

6

4

2

0

Urban
storm water

Agricultural
runoff

WWTP Feed lot Total load TMDL

Nitrogen source

FIGURE 7.15
Nitrogen loads to green river under existing conditions and the best practical treatment under
the national pollutant discharge elimination systems (BPT/NPDES).

$14

$12

$10

$8

$6

$4

$2

$0

WWTP Urban

storm water

Agricultural
runoff

Feed lot Total cost

Nitrogen source

FIGURE 7.16
Costs for nitrogen removal for each source for the best practical treatment under the national pol-
lutant discharge elimination systems.

NEBA approach using nitrogen load and cost of nitrogen control as the envi-
ronmental currency.
The net environmental benefit sought was a reduction in the current
15 kg N day to the TMDL specified load of 12 kg N/day (Figure 7.15) and the
approach should address cost per benefit received. Nitrogen removal costs