up dog poop is not just for aesthetic purposes
Waste Facts from USA Today
06/06/2002 - Updated 09:07
waste poses threat to water
By Traci Watson, USA TODAY
For as long as the dog has been man's best friend,
dog waste has posed a menace to man's nose and foot. Now science has
revealed a more unsavory truth: It's an environmental pollutant.
In the mid-1990s, scientists perfected methods for
tracking the origin of nasty bacteria in streams and seawater. From
Clearwater, Fla., to Arlington, Va., to Boise the trail has led
straight to the hunched-up dog — and to owners who don't pick
up after their pets.
At some beaches, dogs help raise bacteria levels so
high that visitors must stay out of the water. Goaded by such studies,
some cities have directed as much as $10,000 in the last few years to
encourage dog owners to clean up after their pets. A few municipalities
have started issuing citations to those who ignore pet clean-up
Many dog lovers are in denial about their pooches'
leavings. But researchers have named the idea that areas used by dogs
pump more bacteria into waterways — the "Fido hypothesis."
Dogs are only one of many fixtures of suburban
America that add to water pollution. Lawn fertilizers, rinse water from
driveways and motor oil commonly end up in streams and lakes.
But unlike those sources, dogs generate
disease-causing bacteria that can make people sick. Studies done in the
last few years put dogs third or fourth on the list of contributors to
bacteria in contaminated waters. "Dogs are one of our usual suspects,"
says Valerie Harwood, a microbiologist at the University of South
Florida. "At certain sites, we find their effect to be significant."
It doesn't take a Ph.D. to figure out that dog do
is nasty. But it took science to determine how nasty it is.
From mutt to blue-blooded champion, all dogs harbor
so-called coliform bacteria, which live in the gut. The group includes
E. coli, a bacterium that can cause disease, and fecal coliform
bacteria, which spread through feces. Dogs also carry salmonella and
giardia. Environmental officials use measurements of some of these
bacteria as barometers of how much fecal matter has contaminated a body
This wouldn't matter if pet dogs were as rare as
pet chinchillas. But four in 10 U.S. households include at least one
dog, according to the American Pet Products Manufacturers Association.
The association's statistics also show that Americans owned 54.6
million dogs in 1996 and 68 million dogs in 2000. Of that total, 45%
were "large" dogs — 40 pounds or more.
Those numbers add up to a lot of kibble. That
wouldn't matter if all dog owners also owned a pooper-scooper. But
several studies have found that roughly 40% of Americans don't pick up
their dogs' feces (women are more likely to do so than men).
New analysis provides answers
The environmental impact of dog waste went
unrecognized for decades. Then scientists developed lab techniques to
determine the origin of fecal bacteria contaminating water. One method
is a variant of DNA fingerprinting. Another method looks at the
antibiotic resistance of microbes from different species.
Scientists caution that the methods are still new.
They are able to distinguish between major and minor sources of
pollution, but they can't say with precision whether dogs contribute
20% or 30% of the pollution in a stream. "There's inherently some
error," says Don Stoeckel, a microbiologist for the Ohio district of
the U.S. Geological Survey who's studying bacteria-tracking methods. "I
think the best (they) can do is give you some evidence of the magnitude
of each source."
Nonetheless, Stoeckel says, the analytical tools do
provide useful information. Researchers have studied dozens of
waterways. Wild birds and humans usually head the roster of who's
fouling the water. But in some areas, dogs make significant deposits.
At Morro Bay, Calif., for example, dogs contribute
roughly 10% of the E. coli, says Christopher Kitts, a microbiologist at
California Polytechnic State University-San Luis Obispo. "And that can
be the difference between a beach closing and a beach not closing," he
Places where dogs dirty the water:
Creek in Clearwater, Fla. Residents were worried that a
sewage treatment plant contaminated the creek. But when Harwood tested
the water, she found that dogs, along with leaky septic tanks and wild
animals, were to blame for high bacteria counts. Dog feces probably
washed out of yards by the creek, Harwood says.
- Four Mile Run in Arlington and
Fairfax counties, Va. Studies show that dogs add to the
contamination in this suburban Washington, D.C. stream. Officials
calculate that the 12,000 dogs living in Four Mile Run's watershed
leave behind more than 5,000 pounds of "solid waste" every day.
- Boise River in Boise.
The river suffers from high bacteria levels that make it unsuitable for
swimming. Testing of streams and drainpipes flowing into the river
showed that in urban areas, dogs were a leading culprit. In some spots,
dogs and cats account for even more of the bacteria than human feces
— from dysfunctional septic tanks and leaky sewage pipes
Fines don't sway some
Even where dogs aren't the prime offenders, they're
one of the few polluters authorities have control over. At many
California beaches, for example, seagulls and other birds are most
responsible for high bacteria levels. But federal laws protect birds.
That leaves dogs. Officials know that they have a
lot of educating to do before people realize their pooch can be a
canine sewage pipe. Some people find it humiliating to carry a plastic
A survey by the Center for Watershed Protection in
1999 found that of the 41% of respondents who rarely or never clean up
after their dogs, 44% would refuse to do so in the face of fines and
neighbors' complaints. Reasons included, "because it eventually goes
away," "small dog, small waste," and "just because."
So more cities may follow the lead of Laguna Beach,
Calif., a wealthy beach enclave. The city provides pooper-scoopers at
the local dog park. But many people "don't take care of their little
friends," says Victor Hillstead, the city's parks and buildings manager.
So the city hired Entre-Manure, poop-scooping
service based in nearby Dana Point whose motto is "#1 in the #2
Business." Since the city's contract started in January, the service
has collected 187 pounds of dog waste from the city. "I'm real proud of
that fact," says Craig Stern, founder and chief picker-upper. "That's
pollution that'll never reach the ocean."