On July 10 past, two thousand triathletes waded into the Hudson River at 98th Street, to commence the 1.5 kilometer swim ending at Manhattan's Boat Ramp. So began the fifth running of the New York City Triathlon.

On the other side of the continent, weeks earlier, roughly the same number of athletes jumped in a harbor in Oceanside, California, to commence the swim in the Ralph's Half-Ironman.

On the other side of the calendar, weeks later, six thousand women waded into the waters of Lake Washington to start the swim leg of the Danskin race in Seattle.

In all three cases, and in more than a thousand other races around the United States, upwards of a quarter million athletes did and will wonder: How clean is the water in which I'm swimming? That question is not only almost always unanswerable by the athletes themselves, it is a question about which most race organizers cannot give you a precise answer. Most of RDs assume that no news is good news. Absent a water quality expert, or public health official, or at least a lifeguard explicity alerting or prohibiting swimming in a body of water, the race director assumes the water is fine. Fortunately, whether the RD is oblivious or not, his "What, me worry?" approach is on solid footing.

We inquired of health departments and water testing agencies around the country and offer for our readers' purview the following results. If our reports smack of redundancy it is because the way water is tested and graded, lake to ocean, river to bay, is strikingly similar state to state. Though the appearance of a body of water might be widely disparate versus the look of other rivers, lakes and beaches around America, the water quality is gauged to be within certain fairly strict parameters.

To the degree ocean and Great Lake beach water is relatively clean throughout the country, this is in large part due to the Clean Water Act, enacted in 1972 and frequently amended since 1977. But this was just the start. The Clean Water Act, as it was originally passed, targeted "point source pollution." Instead of testing and targeting the water in which a person might swim, the Act attempted to get rid of effluents flowing from a polluting factory, an inefficient sewage treatment center, and the like.

This effort was strikingly successful. Prior to the Clean Water Act, Hudson River fecal coliform counts were routinely in the 2000 colonies per 100 ml of water. Now the readings are routinely below 200 colony forming units (CFU), this directly as a result of secondary water treatment plants. Primary reclamation plants remove roughly 80 percent of the solids and bacteria in wastewater, secondary plants remove about 98 percent.

Starting in 1987 the Environmental Protection Agency, which monitors and enforces the Clean Water Act, entered into partnerships with the states, and such regulatory partnerships exist today. Another element of this legislation was to expand the focus of the Act to oversee beach water, that is, to concern itself with the quality of the "primary contact" water in which we swim and recreate.

In 2000 Congress passed the Beach Act, mandating that each state put in place regulations meeting or exceeding EPA standards for specific bacteriological monitoring. This legislation refers to the 21 states that contain "coastal recreation waters," that is, states with ocean beaches or Great Lakes. The Beach Act does not speak to the other states, nor to the non-affected lakes and rivers in such states. However, an informal monitoring of affected states indicates that they monitor and enforce the same water quality standards throughout their waters that allow primary contact.

As of November, 2004, the EPA published its "Final Rule" delineating water quality criteria for bacteria throughout America's coastal recreation waters. These standards mirror what the individual states have passed as law at the EPA's prodding. What criteria are contained in the Final Rule, and how do they correspond to safe water?

Clean water, from the point of view of the EPA's epidemiologists, means water that is very unlikely to result in illness. Such sickness most often means gastroenteritis (stomach flu), as well as ear, eye, nose and throat infections. But it can mean dysentery, hepatitis, cholera, typhoid fever and, in the famous case of a 1998 triathlon in Springfield, Illinois, leptospirosis.

But what does clean water mean with precision? How do we know numerically what denotes clean water? You get to know this by performing a "surrogate test" for "indicator bacteria." Inasmuch as it's difficult and expensive to test for everything bad in the water (such as leptospirosis) you test for what is easy to detect, on the assumption that where there's smoke, there's fire. The "smoke" the EPA mandates each state tests for is fecal coliform and enterococcus in an ocean, and fecal coliform and e. coli in fresh water.

The standards in an ocean are as follows. If the number of colony forming units of fecal coliform exceed 104 in 100 ml of water, this is considered moderately high and mandates posted advisories at the affected beach, and perhaps other forms of posting (most often website alerts). A beach is also considered moderately unsafe if a "geometric mean" of 35 cfu is present. This means that a beach must exhibit water that is consistently under 35 cfu over the most recent several weeks.

Fecal coliform units must not exceed 400 cfu per 100ml of water, nor a geometric mean of 200 cfu. Exceeding these totals must result in advisories being posted.

What about just closing the beach? This is where states differ. Certain states and municipalities do mandate the closing of beaches when these criteria are exceeded. Others, like California, do not mandate closing, but merely the issuance of an advisory.

In fresh water e. coli is the indicator bacteria, replacing enterococcus. The latter is a bacterium present in human intestines and is a highly reliable indicator of water contamination. It has the advantage of not dieing off easily in salt water, hence its use in ocean testing in place of e. coli.

There are surprisingly good sources of information regarding local water quality. The County of San Diego publishes an exceptional site on the state of its beaches. The best source for California can be found at the Heal the Bay Foundation, where report card style grades are issued for hundreds of beaches up and down California, based on the recent histories of bacterial colonies found during testing at these beaches.

Many local governing agencies report and archive bacterial testing data. An example is the Lake Washington area around Seattle, where the Danskin race was held. One can see historic colony counts, and determine just how clean the water is at the race site (quite clean for Danskin, as a matter of fact).

Though there seems to be a great deal of unanimity and congenial working relationships between advocacy groups and governments at all levels, there appears an occasional bit of discord. At first blush, the grading system used by Heal the Bay and that L.A. County Public Health are identical. Upon closer inspection, however, Heal the Bay is a slightly harder grader than L.A. County. Dockweiler Beach at Imperial Highway gets a D from Heal the Bay, only a B from L.A. County, and so forth. One looks in vain for the beach L.A. County grades more poorly than does Heal the Bay.

This petty conflict is unfortunate, as many or most of the other counties throughout California link directly to Heal the Bay's online report card for an analysis of their beaches.

Were one to look at all of the grades given to California's beaches, the majority rate an A or B from Heal the Bay. The quality at most beaches around the U.S. is quite good. Factories no longer pollute as they once did. Rivers do not catch on fire as they did in the 1960s. Single source polluters are no longer the problem. Oddly enough, we are the problem.

Talk to anyone at the EPA, Heal the Bay, the Surfrider Foundation, they'll all tell you the same thing. Those beaches not rating at least a B grade are certainly proximate to a system of storm drains, estuaries or rivers. Beach water quality problems are now the result of overwatered lawns, and the run-off from communities adjacent to watersheds. Whether inland lakes or ocean beaches, rainwater runoff is the culprit. Fecal coliform counts of 35, and 60, swell to 500, or even 5000, after a rain. "We've met the enemy, and he is us," said Rick Wilson, author of the Surfrider Foundation's State of the Beach annual report. "Municipalities are forced to look at these issues on a watershed basis."

"Our efforts now include inland communities," said Heal the Bay's Mitzi Taggart. "They view water problems in terms of how they can get enough water. We try to express to them that [runoff and watershed sources] are a resource."

Accordingly, rainy conditions prior to an event are most likely the culprit when a triathlon swim leg is cancelled, and this brings us back to the Hudson River. The section chief of the New York Department of Environmental Protection runs the Harbor Survey Program, and as such is responsible for testing at the New York City Triathlon venue. According to this agency's testing, following a rainy spell the fecal coliform count was over 300 cfu on the Monday prior to the New York event. This was clearly higher than the EPA guideline for this bacteriological criterion.

Normally, the testing would not be done again until the following Monday. However, at the request of the race organization follow-up testing was performed, and on Thursday prior to the Sunday race the Hudson River sample taken close to the race course had a reading of 197, a hair under the limit. As the Hudson flushes itself quickly in a current that can flow up to four knots, the trend line pointed to a relatively clean river for the Sunday race, barring further rain prior to the event.

During testing the following Monday, one day after the event, several fecal coliform tests were performed, all of which were extremely low, most in the single digits.

Water quality appears one of those concerns about which government officials, national and local, can justifiably puff their chests. Beach water is clean in America, by and large. There is still a bit of due diligence which can be performed by the end-user, or tri club official were such a duty to be assigned. As noted in the case of California, only advisories are mandated, not beach closings. The information is available, both online and through local testing agencies. Those agencies are easy to find. We were able to find the responsible testing organization in any town we chose, anywhere in America, within 15 minutes of our starting our search.

But, this assumes one does take the time to search and, remember, inland lakes and rivers, excepting Great Lakes, are not covered under applicable federal legislation. The onus is still on the end-user to check. Not even USA Triathlon mandates race directors hold to a clean water standard, but only to abide by whatever the local ordinances or laws require. In the absence of such law, the organizer is absolved by USAT from any responsibility for making sure the water is clean. This throws the responsibility back onto the person who buys a race entry.

What should the enterprising triathlete take from all this? Check with your local county health department regarding the body of water in which you'll swim, pick up the dog poop in your yard, and don't overwater your lawn. Do this, and consider your duty done.