Just north of the H. Smith Richardson Golf Course, a gravel road runs through a narrow slit of trees and hooks right, like a sliced drive. The road is chained shut, and a sign is planted near its entrance.

"Luxury Custom Built Homes. Exquisite Stonework and Trimwork. Custom Built to Your Needs," it says.

Next year, two homes will shoot up on the property, said John Wellner, the developer. What's noteworthy, though, is that the homes -- though they'll sit on Hoydens Lane, one stretch of town that runs mostly on well water -- will be plugged into the public water system.

As with most homes in Fairfield, a turned faucet there will produce fluids fed through pipes by Aquarion, the Bridgeport-based water company that supplies most of this town's water needs from the nearby Hemlock Reservoir.

But as their well-water-using neighbors will be tapping 1,000 feet underground for their own supply of water, they'll need to be extra cautious to not pollute the area.

To some degree, that lesson applies to every Fairfield resident.

The domestic water cycle -- out of wells and reservoirs, into septic tanks and sewage pipes -- is one topic that's most easily ignored. But the process is riddled with points at which contamination could occur.

Most contamination points -- like faulty septic tanks, chemicals running into sewer drains or overly zealous drainage that shuts water out of swaths of soil -- are avoidable.

And to curb them, the Environmental Protection Agency is promoting "National Ground Water Awareness Week," starting Monday. As the agency's Web site says: "It's time to schedule your annual water well check-up!"

While this town has no formal plans for observing the week, several department heads -- in interviews with the Fairfield Citizen -- emphasized the important role that ground water plays for everyone on a daily basis.

"Ground water affects people in different ways," said Bill Hurley, the town engineer. "For people who live without water lines, it's their livelihood. It's the water they have in their house."

For others, proper treatment can mean fewer floods, more vibrant gardens, beaches and forests, and healthier public drinking water.

But what exactly is it?

Ground water, says the Connecticut Department for Environmental Protection, is a vast repository of fresh water located beneath the earth's surface. Rather than flowing through channels, it seeps between cracks and pores, like water within a saturated sponge.

In rural areas of the country, ground water accounts for up to 95 percent of household water supplies. It's used for about half of this country's agricultural irrigation and nearly one-third of its industrial water needs, according to the Environmental Protection Agency (EPA).

In Fairfield, however, those numbers are smaller. But because ground water doesn't migrate much, it's important to care for local supplies.

One major concern lies in septic systems, which, if working improperly, can contaminate the ground water nearby. Sands Cleary, director of the health department, said about 3,000 homes in town -- around 15 percent -- use septic systems.

"Our involvement in terms of ground water protection revolves largely around approving those septic sewers," he said. "Education is something we do day-in and day-out, in terms of installments, and in terms of helping real estate agents, home-owners and contractors. Every day we have people coming in for permits."

Cleary said that septic systems, depending on their age and size, require maintenance work every three to five years. Questions about septic systems should be directed to the health department at (203) 256-3150.

Wells present the second major concern, as they draw directly from ground water and are filtered inside each individual house. Hurley estimates that between 5 and 10 percent of homes in town use well water, which amounts to a maximum of about 2,000 homes.

The Zeisler family, of Hoydens Hill Lane, occupies once such home.

"When people who visit us drink it they always say, `Wow, why does this water taste so good?'" said Yvonne Zeisler.

With that, she filled a glass of well water and handed it to this reporter. Indeed, the water tasted good.

In 2006, the town extended its network of water piping into some of the areas that weren't previously served by the public water system. The idea, Hurley said, was to increase the coverage for fire-prevention purposes. But as an aside, residents of those areas could now plug into the pipe system.

The Zeislers opted not to. It wouldn't have improved the flavor or quality of their water, they said, and it would have cost around $10,000 to do so.

The Zeislers' home is close to the street. But a few houses uphill, a neighbor's home is set back about 50 yards, which meant a significantly higher price-tag for plugging in. The family chose not to for similar reasons.

In 15 years, a resident at the home said, the family has had only one problem with their well, which is located in their basement: on Thanksgiving morning one year, it ran dry. Luckily, they were able to use a neighbor's water for the day and they spent the next day fixing the problem.

Residents of both homes said the proximity of the golf course to their drinking supply did not concern them. The golf course, for one thing, runs downhill from their homes. In addition, they said, they test their water on a yearly basis.

Frequent testing is one reason the EPA runs Ground Water Awareness Week in the first place. On its Web site, it recommends testing wells with the same frequency as one tests furnaces and smoke detectors. Spring is a good time to do this, the agency says, because it is just before the peak water-use season begins. The organization will host a free Web seminar on Wednesday beginning at noon on proper care for water wells and other ground water protection. The seminar can be viewed at http://wellowner.org/.

Peter Grace is no stranger to the process. As the groundskeeper for H. Smith-Richardson golf course, he lives in a home across the street from the course, perched atop a small hill. From his porch, he can see miles over town, across the Black Rock Harbor and into Bridgeport.

"Owning a well can be a hassle, but it has advantages too," he said. Grace has never used public water supplies. He grew up on well water in a town outside of Hartford.

During a recent two-year stretch in Newton, he said, every heavy rain storm meant that his dishwasher would produce brown plates, utensils and bowls.

But that hasn't been an issue for him in Fairfield, yet. The well at his home here has long been broken in. And as with most well owners, his home uses a septic system.

He nodded toward where the well and septic tank are situated in his yard -- in divergent points -- and said, "On the plus side, you don't have water bills."