CONCRETE WASH-WATER: Sources
of the Problem
Concrete is everywhere in areas where
there is a lot of development activity happening. It is used in
the construction of home foundations, large buildings, curbs,
sidewalks, driveways, and for many other purposes. Portland
cement, the "glue" that holds concrete together, is
also found in construction materials like mortar, stucco, and
tile grout.
 Most
of the Lower Fraser area of British Columbia has a high level of
development activity. The photo to the left is of North
Langley. To view the full-sized picture, click on the
thumbnail, then use your browser's "Back" button to
return to this page.
There are also many fish-bearing
streams in the Lower Fraser River area. These streams tend to be
small and are used extensively by coho salmon because of
desirable habitat features like: clean gravel; over-hanging
streamside vegetation; food supply; and undercut banks (see Habitat
Requirements of Fish). Because coho live in these small,
low-flow streams for the first year of their lives, this species
of salmon is especially at risk to sudden episodes of lethal
substances being deposited into the creeks (see The
Salmon Life Cycle).
The wash-water arising from the
installation of a single driveway with an exposed aggregate
finish is capable of causing a large fish kill in the kind of
creek described above. Other activities related to the concrete
industry also have the potential to harm fish and fish habitat.
The following table describes problems related to some specific
activities:
Activity
|
Problem
|
Ready-mixed
concrete facilities
|
Poor
housekeeping and yard runoff, undersized or poorly
maintained effluent ponds with overflow to the
environment
|
Delivery
trucks
|
Poor handling of wash-water
wastes
|
Exposed
aggregate drive ways
|
Disposal of wash-water into
or near catchbasins and drainage systems
|
Stucco
and grout work
|
Disposal of wash-water into
or near catchbasins and drainage systems
|
|
