HomeMy WebLinkAbout0015 . -3-~
GENERAL DISCUSSION
Potential Effects of Dredging on Watar Quality
The following list is not presented se an all-inclusive Bummary, bui as ex-
amples of poten[ial water quality damage which can result from dredging ac-
tivitiesa
1. Water Supply
a. Fresh Water Sources
Dredging can add to water treatmeai costs in the form
of sediment removal, taste, odor, and coloz removal, and
conceivably through the removal of toxic residues put in-
suspension or solution~ Furthermore, present water.supply
treatment methods usually ate not designed for the removal
of many toxic compounds, which thereby be~ome a hazard to
~ public health
~ b. Salt Water Sources
i
~ Salt vater sources are used primaril~.for industrial
cooling water. Where dredging produces sizable quantities
of suspended matter, adverse effects in the form.of clog-
ged intake screens and heat transfer coils can create a
maintenance problem-
2. Bathing, Swi~ing and Recreation
Damages Yesulting from dredging in this water-use category '
relate principaZly to aeathetic qualities. The presence
of high turbidity, acum. eludge, odors, and color which
could result from dredging Would be aeathetLCally unac-
ceptable in recreational areas. The public health as-
pecte of water qualitq damage becomes a problem when
toxic, e-g: peaticide, campounds are dispexsed.througl-.
disturbance and tranaport of aettled material
3. Fish Propegation . ,
- Dredging can effect a change in pH or dissolved oxygen
as a result of disturbing anaerobic aediaienta. TDis
action can be detrineatal to fish end othe aquatic
life . Iastances have been reported of d~g~e •to f~ + , ,
from long-term expoaure in highlq turbid vaters~ The
potential for exposure of toxic sedimeata is alio a
po~s~bility in anq dredging activity. Perhapi the
greatest amount of damage to fi~h propagatioa 1reAU~ts
in damage to member• of the food chain• Increaaed
~ eolor or turbidity caA reduca the growth of planktoa
neceaeary to the fi~h food cqcle. Siltaiton can
deotroy valuable bottas faupa.
. t R ~ ?
~
~OOK~~87 PAGE 1~