Water Quality Management - River Dynamics and Integrated River Management - page 615

Summary —The water quality problems discussed in this Chapter are some of the most important and
difficult to solve water-quality management issues. Considerable time and money have been and will continue
to be expended on the solution of these problems in developed countries, and these are key problems that
must be dealt with as developing countries seek to improve their water environment. However, there are
many other well-known water quality problems that were not discussed in detail here because of space
limitations including: acid rain, acid mine drainage, pesticides, herbicides, heavy metals (away from the
sediments), and temperature. Further, a number of new water-quality problems have emerged in recent
years such as pharmaceuticals, personal care products, and endocrine disruptors. Despite these many
water-quality problems, substantial improvement in the quality of rivers in the U.S. and Europe have
been made particularly since the 1970s and the passage of the Clean Water Act. Thus, through societal
dedication to solving these problems and the expenditure of the time and money needed to enact and
maintain the solutions developing countries can similarly reduce water quality problems and consequently
improve public and ecologic health.
Review Questions
1. Short Answer:
a) What are the scientific, economic, and legal definitions of pollution?
b) Define CBOD, NBOD, and COD.
c) List the components of the dissolved oxygen balance of a stream.
d) Why was the Streeter-Phelps equation acceptable in the early days of stream sanitation studies?
e) In what ways can benthic deposits potentially affect stream dissolved oxygen?
f) Why might field measured “SOD” values be much greater that the best reachwise average values?
g) List the disadvantages of the well known equations for estimation of the reaeration-rate coefficient?
h) Under what conditions are “bottle” estimates of the BOD decay rate representative of instream
conditions?
i) What has been the traditional complaint against the inclusion of photosynthesis in the consideration
of allowable pollutant loads?
j) List the key habitat features that define physical integrity for aquatic ecosystems.
k) Describe the different aeration systems that could be applied to rivers.
l) In what ways do nitrogeneous contaminants influence water quality, the aquatic environment, and
public health?
m) Define eutrophication and algal blooms.
n) What problems are caused by algae?
o) List agricultural best management practices (BMPs) for nutrient control. Which BMPs or combination
of BMPs are most effective for nutrient management?
p) Why have numerous water bodies experienced increasing pollutant concentrations even though
extensive agricultural best management practices have been installed in the upstream watershed?
q) List urban best management practices (BMPs) for non-point source pollution control.
r) Name and describe three water borne diseases.
s) Describe the problems with the indicator organism approach to detect and monitor pathogen
contamination.
t) List and describe the steps of microbial risk assessment.
u) Discuss the effectiveness of the various methods for the disinfection of wastewater.
v) Describe disinfection by-products.