The use of CuS04 as an algaecide and the RECO RULE for compliance of
disposal of treated water by COOP sites.

<Lynnette.J.Ansell@NOAA.gov>

The statement has been made that the Copper Sulfate solution may not be
dumped on the ground. This is straightforward and correct. This
constitutes ground disposal and is not permitted. However, the process,
as I understand it, used by NWS Observing Handbook #2 does not call for
the dumping of a " copper sulfate solution." The product of evaporation
pan process is precipitation, dirt, and slimy, dying or dead algae.

Copper is used by plants, and is an essential part of their
photosynthetic pathways. Copper has a marked effect on the formation and
chemical composition of cell walls, making leaves and fruits and
distribution of water. Greater than 50% of copper localized in plants,
is found in the chloroplasts. Copper becomes part of the proteins, which
catalyze terminal oxidation within the mitochondria. Copper transfers
electrons to become part of the proteins, which oxidize monophenols to
diphenols.

Should early change out become necessary, excess copper sulfate solution
can be remediated by placing 1-3 iron penny nails into the pan or
container. The copper will precipitate onto the nail and iron sulfate
solution is formed in a single replacement reaction within several days.
The color will change from blue to orange to clear with a muddy brown
precipitate. Decant the liquid, and rinse down the sink. Place the
precipitate in the trash.

CuSO4 + Fe \--\> FeSO4 + Cu

Copper sulfate + iron \--\> iron (II) sulfate + copper

COPPER TOXICITY -

Keep perspective: Plants utilize copper and like vitamins for people
above a certain level, become detrimental to growth. Also, keep in mind
that the quantity of CuSO4 in evaporation algae inhibitors is
*extremely* small and the copper cycle appears to dead end.

The studies of the toxicological results of the use of copper sulfate
are related to watershed management, ecological systems, shoreline
control and food chain impact.

-For most plant species, the critical toxicity level of copper in the
leaves is considered to be above 20-to 30-g/g dry wt. There are marked
differences in copper tolerance among plant species; these differences
are directly related to the copper content of the shoots.

-A large copper supply usually inhibits root growth before shoot growth.
This does not mean, however, that roots are more sensitive to high
copper concentrations; rather, they are the sites of preferential copper
accumulation when the external copper supply is large.

The use of chemicals, such as copper sulfate, is often the chosen method
of algae and weed control. These compounds have been on the market for
decades and are believed to be safe based on short-term studies. The
long-term implication of copper in our waterways is less understood
(Dana Oleskiewicz, OSU Extension Agent, in Watershed Management). As a
standing practice, NOAA should continue to review the use of any
chemical products.

Scientific research conducted on these algaecides consists of short-term
effects, dissipation of the chemical from the water, and the toxicity to
specific animal species. According to these studies, the chemicals
appear safe to water systems and have been approved for use at the
recommended dosages. When applied correctly, they are not acutely or
chronically toxic to non-target aquatic species.

There are studies; however, indicating that there are negative effects
involved in the use of chemicals to control algae and aquatic weeds.
Specifically, these chemicals can be toxic to zooplankton or fish food,
adversely affect the important microbial system in the sediment and
water column, and cause a shift to a monoculture or undesirable species.
They can impact the sexual reproduction of organisms and can interfere
with the metabolism or cause chromosomal mutation in non-target aquatic
organisms.

Copper resistant strains of algae have appeared, which is analogous to
the overuse of antibiotics in humans causing resistance to medicine. In
addition, there are very few long-term studies on the impact to water
systems from prolonged chemical exposure. Research is limited on the
combined effect to the ecosystem with few studies being done within
waterways rather than in laboratory-controlled environments.

Reviewed with Jim.Farr, PhD 9.2.03.