We pour it down the drain without thinking and buy it for more than $1 a bottle without a second thought. It puts out fires, causes floods. Almost three-quarters of the earth is covered by the stuff, yet people go thirsty. Water can be cheap or expensive, good or evil, everywhere but nowhere.

In food, water is similarly two-faced. A natural constituent of many foods, it is also a crucial added ingredient. On the other hand, it's an age-old adulterant. Either way, it seeps into the most surprising places:

When you buy a fresh chicken, up to 8 percent of its weight is permitted to be added water. During processing, chickens are dipped into chilling tanks, where they absorb water. In the late '70s, an attempt was made to require that net weight reflect the weight of the chicken only. It never got anywhere. So right now, you pay for that water.

Seafood, pizzas and other foods are typically sprayed with water before they are frozen, to keep breading or cheese intact, prevent dehydration and extend shelf life. Labels on frozen products must reflect the weight before misting, but the government seizes a handful of products per year that haven't been weighed prior to the addition of water.

According to the Food and Drug Administration, shrimp and lobster are the most common victims of "overglazing" -- unscrupulous manufacturers have added up to 40 percent of the seafood's weight in water. As for meat and poultry, the U.S. Department of Agriculture has turned up some chicken nuggets whose glazing weights were not being subtracted from their net weights.

Instant coffee? The FDA recently began surveying roasted ground coffees to determine if excessive moisture is being added to the can as a result of a manufacturing process. Although there are currently no standards for moisture levels in coffees processed in this fashion, the agency believes that at least one company has added excessive moisture to its product by not evaporating the water used to cool the roasted beans.

If there are standards for how much breading can be on fried, frozen shrimp (50 percent -- and a handful of manufacturers still cheat, according to the FDA) or how many cherries must be in a pie (25 percent of the weight of the pie), then it should follow that there are laws governing how much water can be added to a hot dog (up to 10 percent).

In fact, for many foods, there are limits as to the percentage of water that can be added. These government standards are about as exciting to read as an unabridged dictionary; nonetheless, their purpose is to prevent manufacturers from overwatering their products and to maintain expected quality.

The food label doesn't specify what those percentages are, although the water content of some foods is defined in the title of the product. "Turkey roll," for example, can have up to 2 percent added water. Water detection gets trickier with "turkey with added broth," which can have an unlimited amount of water added -- and even trickier for the supermarket shopper when the package label is behind the deli counter.

While the cost of the water used to emulsify a single hot dog isn't going to break the bank -- collectively, we probably end up paying a lot for this innocuous liquid.

But there's a flip side. "In an era when we're concerned about fat consumption, we may not want to be so hostile to added water," said Carol Tucker Forman, a consultant and former assistant secretary of agriculture for food and consumer services at the U.S. Department of Agriculture. Forman encourages alternative standards permitting more water in processed meats to replace fat.

Here are some foods in which the government is -- and isn't -- keeping track of their flow:

Oysters. When raw oysters are shucked and cleaned in preparation for packaging, water and air are "blown" through them. According to Mary Synder, an assistant to the FDA's director of regulatory guidance, there are specifications as to how long the water can flow through the oysters, and regulations that the oysters be drained thoroughly after they are cleaned.

While the liquid in the container must come from the natural fluid from the oysters only, the agency has gotten a lot of complaints from consumers about watery pints, Synder said.

Catfish. The FDA has discovered a farm-raised catfish company that has been pumping up the weight of its fish more than 10 percent. In this case, two food additives, lemon flavoring and tripolyphosphates were diluted in water and injected into the fish. Unfortunately, according to FDA, the water wasn't being declared as an ingredient, nor was its percentage listed.

Ham. In 1985, the USDA issued a set of "protein fat free" (PFF) guidelines, which indirectly keep track of the water content of hams by requiring certain protein percentages. The more water and other additives in a product, the more diluted the protein content.

Four categories were designated by USDA: "Ham," which may not contain less than 20.5 percent protein; "Ham with natural juices," with a minimum 18.5 percent protein content; "Ham -- Water Added," a minimum 17 percent protein and "Ham and water product," which has under 17 percent protein and an unlimited amount of water, although that amount must be stated on the label.

Hot dogs. Recently, hot dogs have been under water scrutiny. Aside from the 10 percent added-water cap for hot dogs, the product is permitted to have a certain amount of water that naturally occurs in the meat. That amount of water is determined by a ratio of 4:1. For example, if a hot dog is 12 percent meat protein, then 48 percent of the product can be comprised of naturally-occuring water.

What's been happening, however, is that processors are counting non-meat protein sources such as autolyzed yeast or hydrolyzed vegetable protein as protein. Thus, the ratio is getting ewed with more water because the protein isn't all coming from the meat. The USDA has proposed a regulation that would require processors to subtract non-meat proteins from the ratio calculation.

Canned fruits and vegetables. Aside from a few exceptions, government standards do not specify the maximum amount of water that canned produce can contain.

While there are five categories of "fill" guidelines, most canned produce falls under the category that requires filling the can to not less than 90 percent (by volume, not weight), according to Nan Rainey, a supervisory chemist with the FDA's food standards division. However, the 90 percent includes both the liquids and the solids, so manufacturers have flexibility -- if they want it -- to juggle the combination.

The National Food Processors Association says that good manufacturing procedures ensure that there is not much variation between how much produce one company puts in its cans versus another -- so long as you're comparing oranges to oranges. Other observers believe that competition in the marketplace prevents one corn company from packing its cans with significantly less corn than another.

Nevertheless, the issue of determining how much produce consumers are really paying for surfaced in 1975, when the FDA proposed that labels of canned fruits and vegetables designate the drained weight (the weight of the produce after processing -- minus the liquid). Then in 1977, the agency issued a new proposal, suggesting that processors have the option of labeling their cans with either drained weight or "fill weight" -- the weight of the food in the can prior to processing.

Not surprisingly, the canners objected to both proposals, contending that it would cost them over $100 million to comply with mandatory drained weight labeling requirements and about $20 million to comply with fill weight, according to Allen Matthys, director of regulatory affairs at the National Food Processors Association.

Neither proposal was adopted, and the industry instituted a voluntary fill weight program. That's why only some cans of produce are currently labeled with two weights: a 16-ounce can of Town House cut green beans contains 8 3/4 ounces of vegetables, while the label on the Giant brand only says "net wt. 16 oz."

Other standards minutiae: canned tomatoes are not permitted to have any added water -- only tomato juice. Canning tomatoes in tomato juice was a common industry practice back in the 1940s, according to Matthys, and it just stuck.

Diluted fruit juices. Among the issues that food lawyers and lobbyists make their living from, this fluid fiasco has been going on for years.

At stake is a 1974 proposal that all diluted juices state the percentage of juice in the product. While some manufacturers already divulge this information voluntarily -- and, in fact, use it as a marketing tool -- only the labels of orange juice products were ever required by law to do so. The 1974 proposal for all juices was finalized in 1980, but never went into effect