Ever since her former husband stopped paying child support, Sandra Salyers has held two jobs to support her teen-aged daughters, Karen and Shelly. She orders materials for a Fairfax County electronics firm and works part-time evenings and Sundays at Hechinger's.

It was particularly galling to her, then, when her former husband recently sold his Falls Church house and relocated to Canada, still nearly $2,000 in arrears on support payments and apparently unscathed by any enforcement efforts by Virginia officials.

"They {state officials} could have done something when he got behind," including putting a lien on his house or trying to garnishee his wages as a carpenter, said Salyers, who worries that collection may be impossible now that her former husband lives across the border.

Attempts by a reporter to contact her former husband were unsuccessful.

Salyers' case is one of more than 245,000 currently being handled by Virginia's troubled Child Support Enforcement Division. The custodial parents are owed more than $270 million, a figure that officials say would be far higher if the state could establish paternity in more than 60,000 of those cases.

The Virginia General Assembly this session is considering legislation proposed by Gov. Gerald L. Baliles' administration that would address the crisis on two major fronts: helping establish paternity and increasing the state's ability to collect payments.

Still, for Salyers and others like her, the proposed improvements appear to be too little too late. A number of custodial parents and their attorneys say that the only way to get payment from some delinquent noncustodial parents, more than 99 percent of them fathers, is by putting them in jail or in a work-release program.

"Fathers disobeying court orders is the most prevalent unprosecuted crime in the country," said George DePolo, a Prince William attorney who represented Salyers before her case was turned over to the child support division. "If people knew that when they fail to make child support payments they are going to find their butts in jail, they will start paying."

Others disagree, saying this would not take into account circumstances that may prevent a noncustodial parent from paying and could make matters worse by getting the delinquent parent in trouble at work.

About half of the female-headed households in the country get all the support they have been awarded, while a quarter get less than ordered and another quarter get nothing, according to the U.S. Census Bureau. This contributes to a growing number of women and children living in poverty, national children's advocates say.

The state and federal governments together pay $166 million annually in Aid to Dependent Children for the 55,000 public assistance cases the child support division handles, and Virginia is under federal orders to improve collections to reduce these welfare costs. Absent parents have been identified and ordered to pay support in less than a quarter of these cases, according to state figures.

Virginia has done such a poor job of collecting child support for welfare recipients, it faces $10 million in federal penalties for fiscal 1984 through 1988, state officials said.

The child support division, created in 1985, got off to a rocky start, in part because of a defective computer system that failed to direct payments properly. In 1986, Virginia ranked 53rd among 54 states and territories, collecting an average of only $75 per case, according to the U.S. Family Support Administration.

The District ranked 51st with $98 per case, and Maryland ranked 14th at $490 per case. Virginia officials say they made great improvement last year, when they collected $300 per case.

Also, Virginia officials say they are testing a replacement for the computer system and that with additional staff they have cut the amount of unidentified payments stuck in the state bureaucracy from $348,000 at the beginning of last year to $51,880 at the end.

Still, each of the division's 155 investigators handles an average of about 1,500 problem cases, and about a third of the absent parents involved live in other states. The caseload is so high that officials acknowledge difficulty in going after delinquent parents right under their noses.

Frieda Elliot, who lives in a two-bedroom apartment in Manassas with her three children, says the division's Fairfax office knows exactly where to find her husband, who she claims owes her $10,000 in court-ordered support for the past four years.

"He lives right down the street from child support enforcement," she said. "They {the division} never do anything. They said they were going to garnish his wages, but they never even contacted his work" at a Centreville construction company.

John Elliot Jr., her estranged husband, declined to discuss the situation.

Frieda Elliot said her only income is the $6.85 an hour she makes as a stockroom clerk, a wage too high for her to qualify for public assistance. She adds that her income is too low to afford baby sitters for her children in the afternoons, leaving her 12-year-old son to care for his 6- and 7-year-old siblings.

One of the most basic problems the state has in getting appropriate child support payments made is establishing paternity. Although federal law requires that paternity be established in 75 percent of all public assistance cases, Virginia says it has done so in only 42 percent of the cases.

One of the most effective ways men now have of getting out of paying child support is simply not to show up in court for their paternity hearings, state officials say.

Both chambers of the General Assembly have passed bills that would grant courts specific authority to take evidence, establish paternity and determine child support payments if the named father fails to appear. Officials estimate that they could establish paternity in 3,000 more cases a year with this change.

Once support is ordered, the next step for enforcement officials is forcing payment.

"We deal with a very elusive group of people," said Harry W. Wiggins, director of the child support enforcement division.

One of the main new tools the division would get from pending legislation is the automatic withholding of child support payments from the noncustodial parent's paycheck, unless both sides agree to an alternative or the noncustodial parent convinces the court that he or she will pay on time. Also, the division would gain subpoena powers over an array of financial records, avoiding the delay of going through courts and making it easier for enforcement officials to find assets of the noncustodial parent.

The state Senate approved that legislation, though some senators voiced reservations about needlessly harassing well-intentioned parents.

Opponents argue that immediate withholding would make it more difficult for the noncustodial parents to get and keep jobs because employers will not want to process the withholding. Others say that the $5 per withholding the employer receives, also taken out of the employee's paycheck, more than compensates for the extra work.

Wiggins estimates that these enforcement tools would enable the state to increase collections by $10 million to $20 million in the first year.

Patricia Coupe, who lives in a two-bedroom apartment in Reston with two of her three children, ages 11 to 18, says the proposals being considered would not help her situation. According to Coupe, her former husband lives in New York and changes jobs whenever she attempts to have his wages garnished for the $37.50 a week he has been ordered to pay.

"Put him in jail, and then he'll know the girl means business," she concluded.

Reached in New York, Edward Jenulewicz declined to comment.

Stephen Balazs of Loudoun County has seen the child custody issue from both sides, first as noncustodial parent and now as custodial parent of a 15-year-old son and 12-year-old daughter. Balazs, a computer repairman for AT&T, said he paid his child support regularly to his former wife but could not even get his children's report cards or class pictures.

Now, he says, his wife has moved to California and owes more than $3,000 in support, though she has a full-time job as an insurance adjuster.

"Females are just as much deadbeats as fathers," Balazs said.

Balazs' former wife, contacted in San Jose, said she would not respond.

Whether male or female, custodial parents say their kids are the ones on the losing end of the support battle, not only financially but also emotionally as former spouses use nonpayment of support as a weapon in often spiteful divorce wars.

Karen Houston, Sandra Salyers' 15-year-old daughter, recounts how her father called her last fall and arranged to pick her up for a visit. "He never came and got me," she said. When she and her mother tried to find him, they discovered through a forwarding address at the post office that he had left for Canada.

Karen wrote to him there: "At least when you called or were paying child support, I felt a little supported, but now I feel nothing . . . . Your problem is you know my mom would never let us do without, so you left it all up to her."

Karen wrote that she never wanted to see him again and signed the letter "your ex-daughter." But in a postscript, underlined, she added, "Write back very soon."