Why Are the Suburbs So Sad? : THE WATERLINE <i> by Joseph Olshan; (Doubleday: $17.95; 320 pp.; 0-385-26505) </i>

In the novel “The Waterline,” we find ourselves in suburbia, 45 minutes from New York City. Not quite the Eastern suburbs of John Updike or John Cheever, but a place more spiritually facile and less moneyed. So completely does it fit stereotypes of suburbia that initially the inhabitants don’t seem very interesting--on the surface at least. They’re either driven or bored. It’s a world much like the movie version of “Fatal Attractions”: self-serving, work-obsessed and adulterous.

In an early scene, a husband is going to work. He chooses a pink shirt, a paisley tie. His wife, still in her robe, sits on the end of the bed. She feels a sense of fear, and also of entrapment. She has no money. She has no work. They no longer make love. She suspects infidelity.

On top of everything, their child, who is 7, has recently witnessed the drowning of a 2-year-old boy in a neighborhood lake. The boy is the only person who could have saved the tot and didn’t, even though he had been taught how to swim. He suffers trauma, blaming himself for the child’s death, as do the drowned boy’s parents. In short, things are unraveling in this split-level sanctuary.

From the beginning, the Kaplan family is seriously out of kilter, even before the drowning draws them into a neighborhood maelstrom. Michael Kaplan commutes to a job in Manhattan that seems all-consuming and argues with his wife, Susan, over tellingly miserable topics, such as her purchase of a $750 dress. It’s not difficult to see the banality in such confrontations. The woman shops to fulfill her life and her physical fantasies of herself; the man controls the purse strings and therefore the paths to humiliation.

They are no more honest with their son than they are with each other. After the accident at the lake, Susan tells Billy that the drowning victim “decided to go to heaven,” making it sound like he exercised a vacation option. (In what kind of a world do parents tell 7-year-olds such things? Westchester?)

There is also a curious disregard for the feelings of the drowned boys’ parents: The Kaplans want only for their son not to be blamed. They are conspicuously unforthcoming with sympathy for the dead boy’s family. And they are almost paranoid in their self-indulgent concerns. Will they be held responsible? Will Billy be ostracized? This self-concern extends to all corners of the Kaplans’ life and makes them seem hemmed in and small.

Seven-year-old Billy is on an edge, even before the accident. His estrangement from his father is described by his mother this way:

“I just wished Michael took more opportunities to spend time with Billy. Too often he bypassed his son’s room and Billy had to seek him out. Look how much love there was between them. Why weren’t they together more often? Why did Michael have to go off weekends and do other things?”

Why, indeed?

“I knew Billy missed him and felt excluded from his father’s recreational activities. It pained me that there was so much feeling but no strong connection between them. It was like heating a bedroom in the winter and never sleeping in it.”

It’s also very much like describing problems clinically (they loved each other but, you know, they couldn’t connect). Bit by bit, this sort of abandonment destroys the spirit. (“They melt from you, your sons. Your arms grow full of rain,” goes the lines from Derek Walcott which the author has used for an epigram.)

Not even boredom, which we know can be deadly in the suburbs, can account for Susan Kaplan’s worries. She suffers, we know, but from . . . what? She is jobless and yet employs a Guatemalan maid, Mercedes, who hovers in the background, and whom she treats as an automated device.

What about these problems in the Kaplan family--an ignored Billy, Michael’s infidelity, Susan’s passivity? “If there was to be a confrontation about infidelity,” reasons Susan quite lethargically early on, “it needed to occur in a different arena.” That arena, however, is hardly entered. The combatants simply walk away from each other and hollow out their marriage.

Fleetingly, more empathy emerges in the sections where we hear the boy describe his unhappiness and in passages dealing with Susan’s younger sister, Tina.

Tina--married, a mother, and temporarily confined to a mental hospital nearby--is agoraphobic. That is to say, she has an extreme fear of crossing distances or being in open space, a fear which also will affect Billy by the time he reaches college.

Tina’s craziness is touchingly real, and so is Billy’s concern with it being his own fate. With Tina, as with Billy later on in the story when he tries to take stock of himself and flirts with suicide, we feel the toughness of life and the sorrow of things gone all wrong. The author, Joseph Olshan, makes us feel much more for these wounded outsiders than we ever do for Susan or Michael.

Cheever knew the pull of tragedy. He knew you could have rather lousy values, be stuck in worlds of denial and dishonesty, cheat on your wife, lust after the wrong things, err time and time again in a bumbling, helpless way, be afraid of innumerable things and know it and yet know at the same time that it was the amount of effort you could make at being honest that finally counted and--not coincidentally--mattered to the beauty and stature of a story. What “The Waterline” wants for is more of that kind of reckoning from its characters.