Herbicide ban clogs canals

[Guest guest]

(Surely, people with inventive minds could develop methods for removing the

algae. At Wakulla Springs (down the road from us here in Tallahassee), they

have a floating hydrilla chopper that slices through the growth like a hot

knife thru butter. The algae grows as a result of fertilizer rich runoff as

well as heat. Containing fertilizer on site would help. To clear the drip

irrigating nozzles, possibly creating a local ecosystem to eat the algae or

....shucks, if you put a few engineers in a room for a couple of hours with a

water specialist, there is no telling how many methods they could come up

with. )

http://www.modbee.com/metro/story/0,1113,276367,00.html

Herbicide ban clogs canals

By TIM MORAN

BEE STAFF WRITER

(Published: Thursday, June 21, 2001)

Losing the use of a herbicide has put irrigation districts in chains --

and they are not happy about it.

Modesto and Turlock irrigation district workers have resorted to

mechanical methods, including dragging chains through canals to break up

algae, because of a federal court ruling in Oregon.

The court ruled that an agency using the herbicide needed a state

discharge permit to comply with the federal Clean Water Act.

The MID and TID were not involved in the case, but have suspended the

herbicide's use while seeking state permission to use the chemical again.

The MID, which supplies some of the Modesto area's drinking water, had been

adding the herbicide to the canal system downstream from where water is

diverted for drinking.

In addition to dragging chains through canals, the MID is using special

buckets on backhoes to remove algae and other vegetation, said Walt Ward,

assistant general manager of water resources.

Ward said the district has hired four temporary workers to help with the

project.

The algae causes problems for farmers who have drip or microirrigation

systems, said Kate Hora, a spokeswoman for the MID. The algae clogs filters

and small irrigation nozzles used in those systems.

A couple of farmers may have reverted to using well water to circumvent

the problem, Ward said.

The problem is most severe on the West Side, because canals there are

shallower and the water has been exposed to sunlight longer, promoting algae

growth, Hora said.

Hot weather could make the problem worse, Ward said.

Another option to combat the problem is using microbes that eat algae,

Ward said. It would have to be done as an experimental study, because

microbes are typically used in stagnant water rather than moving water, he

said.

The state Water Resources Control Board is working on a master permit for

allowing herbicides with appropriate environmental controls, Hora said. The

permit is not expected to be ready until later this summer.

In the meantime, chains and backhoes are the most viable option.