AGEC/FNR 406                                                         LECTURE 33
This presentation is the property of its rightful owner.
Sponsored Links
1 / 13

Low Medium High Very High PowerPoint PPT Presentation


  • 74 Views
  • Uploaded on
  • Presentation posted in: General

AGEC/FNR 406 LECTURE 33. Groundwater nitrate risk:. Low Medium High Very High. Source: http://pasture.ecn.purdue.edu/~frankenb/watershedmap.html. Types of water pollutants.

Download Presentation

Low Medium High Very High

An Image/Link below is provided (as is) to download presentation

Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author.While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server.


- - - - - - - - - - - - - - - - - - - - - - - - - - E N D - - - - - - - - - - - - - - - - - - - - - - - - - -

Presentation Transcript


Low medium high very high

AGEC/FNR 406 LECTURE 33

Groundwater nitrate risk:

LowMediumHighVery High

Source: http://pasture.ecn.purdue.edu/~frankenb/watershedmap.html


Low medium high very high

Types of water pollutants

1. Organic wastes: degradable wastes, residuals, some chemicals (detergents, pesticides, oil).

2. Inorganic substances: toxic metals, salts, acids, nitrate and phosphorous compounds.

3. Nonmaterial pollutants: heat, radioactivity.

4. Infectious agents: bacteria, viruses.


Low medium high very high

Sources of water pollutants

1. Point sources: industry and municipal sewage treatment plants. “end of the pipe” typically continuous emission typically governed by Federal (EPA) standards

2. Nonpoint sources: agriculture, yard, and street runoff

hard to monitor episodic governed by states


Low medium high very high

Federal Policy

1965 Water Quality Actrequired states to set ambient standards for water quality1972 Water Pollution Control Act Amendmentsset a “zero discharge” standard (inefficient!)set technology-based effluent standards and federal discharge permits1977Clean Water Actrequired Best Conventional Technology


Low medium high very high

Biological Oxygen Demand (BOD)

High quality water is usually associated with a high level of dissolved oxygen (DO).

DO is typically used up in the degradation process.Main source is treated municipal wastewater.One way to measure water quality is via “biochemical oxygen demand.”


Low medium high very high

DO profile

DOppm

Time or distance


Low medium high very high

Emission vs. Concentration

R


Transfer coefficient

Transfer coefficient

A transfer coefficient measures the per unit relationship between a level of emission at a source and a constant concentration of the pollutant at a receptor site.


Transfer coefficient1

Transfer coefficient

I

ai Ei + B

KR =

i =1

KR = concentration at receptor site

ai = transfer coefficient

Ei = emission level of ith source

B = background emission, if any


Cost effective clean up

Cost-effective clean up

Policy Goal: Obtain given concentration target (not emission target) at minimum cost.

Procedure: translate emission reduction into concentration reduction.

Concentration = emission x transfer coefficientMC of concentration reduction = MC of emission reduction / transfer coefficient


Example

Example

Two sources, one receptor site.

EA= 10/day, a = 0.50, MC = 100

R

EB= 10/day, a = 1.0, MC = 100

Concentration at R = 10*.5 + 10*1.0 = 15

MC of concentration reduction = 100/0.5 = 200 for A

MC of concentration reduction = 100/1.0 = 100 for B


Low medium high very high

Zone Approach

B

C

A

R

Standards based on zone may be useful when monitoring costs are high


Low medium high very high

Key Points

Goal: reduce damages at receptor site at lowest cost

How: balance the impact each polluter has(not on emission, but on concentration) with cost of reducing damages (in terms of concentration)

Key concept: Target concentration, not emission.


  • Login