New formulations of dishwasher detergents will help reduce the
amount of phosphorus getting into lakes and streams throughout the
United States. As of Thursday, detergents containing more than 0.5
percent phosphorus by weight will be banned in Washington and 15
other states, as I reported in a story in
yesterday’s Kitsap Sun.
If you don’t live on a lake and never go swimming or boating in
a lake, this may seem like a needless effort. But when you see
excessive algae blooms and plant growth in a lake, there’s a good
chance that it is related to the amount of phosphate flowing into
the lake.
It is interesting that this phosphate issue comes up in the same
month that I have been writing about new state and federal permits
to bring pesticides into compliance with the Clean Water Act.
See Water Ways, June 9. Under current state permits, it is
fairly easy to get approval to kill the weeds in your lake. But
this does nothing to remove the phosphorus that feeds the plants,
if that is what is promoting the weed growth. See the Environmental
Protection Agency’s website
on nitrogen and phosphorus pollution.
Phosphates in laundry detergents were essentially banned in 1994
in Washington state. On Thursday, the ban is extended to dishwasher
detergents. That still leaves what is generally the largest source
of phosphates to our water bodies: fertilizers from lawns — and
especially from farms in some locations.
Do people who live near lakes make the connection that their
green lawns may be contributing to their green lakes?
This is an old story in Michigan and Wisconsin, where people
have been struggling for decades to keep their lakes healthy. In
2004, Dane County, WI, took the bold step of banning phosphates in
fertilizers, following research that showed that most soils in the
region already had adequate phosphorus for plant growth. Now,
unless a soil test confirms the lack of phosphorus, it is illegal
for county residents to apply fertilizer containing phosphate. See
Phosphorus
Control in Dane County.
I’m not sure if this ban on phosphate fertilizers is an option
anywhere in Washington state, but people probably could use
low-phosphate fertilizers, especially near lakes, or at least they
could conduct soil tests to see what nutrients need to be
added.
Another option is to reduce or eliminate your lawn, switching to
native plants that thrive in natural soils found in the region.
I find it interesting that some people are now calling on
residents who live in the vast watershed of the Mississippi River
to eliminate their lawns as a result of the oil spill in the Gulf.
Check out
“Want to Help the Gulf of Mexico? Kill Your Lawn” by the Ocean
Doctor.
Here’s the argument: The Gulf already suffers from a low-oxygen
problem blamed on fertilizers coming from farms and homes
throughout 40 percent of the continental United States. Methane gas
being released from the BP blowout is fertilizing the plankton that
contribute to the low-oxygen problem. The risk is high that many
fish and other creatures will be killed as a result of a massive
dead zone likely to be created. Since nobody seems able to stop the
gushing oil, people may reduce the damage by eliminating their use
of fertilizers.
I’m not sure if this makes sense, just as I’m not sure if the
use of phosphate-free dishwashing detergents will make much
difference. Researchers should be able to help us with these
calculations. But if we can live without excessive phosphates —
nitrogen, too, in the case of the ailing Hood Canal and South Puget
Sound — then maybe it’s worth a try.
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