East Bay Municipal Utility District customers have been hit with water rate increases every year since 1995, pushing up the price at four times the pace of Bay Area inflation.

On Tuesday, district directors will consider more, and even larger, annual increases for residents of much of Alameda and Contra Costa counties: 9.75 percent for the fiscal year starting July 1, and 9.5 percent the following year. If approved they would result in tripling of rates from 1995-2015.

For an average single-family district household, the monthly water bill would increase 20 percent over the next two years from $40.45 a month to $48.60. Similar wastewater fee increases are planned for the parts of the district receiving that service.

Reasonable water rate increases make sense to encourage conservation of a precious resource. Paradoxically, as district officials note, reduced consumption can necessitate more rate hikes to cover fixed costs. District officials also say they need more money to replace aging infrastructure.

However, they gloss over a third cost driver: The price of employee benefits, now at 70 cents for every dollar of payroll. That includes some of the best pensions in California among workers who aren't police or firefighters.

Officials don't mention in their rate analysis or budget that employees make only a small contribution to retirement benefits, or that, while on the job, they and their dependents can receive free Kaiser medical coverage.

So while asking ratepayers to kick in more, will EBMUD officials insist that employees do likewise?

The district, run by a labor-friendly board, is currently in negotiations with employee unions. As a result, officials falsely claim, they cannot specify how much they plan to spend on salaries and benefits.

Those underlying assumptions are key to budget forecasts the district uses to justify the rate hikes. Thus, while the district will hold a public hearing Tuesday, it will withhold information essential for determining if the increases are reasonable. Directors are essentially telling the public to just trust them.

Past practices are not reassuring:

Pensions: The district runs its own retirement plan, offering most workers pensions equal to up to 2.6 percent of top salary for every year on the job. For a 30-year employee, that works out to 78 percent of salary.

EBMUD employees also participate in Social Security. The two benefits combined allow career workers to retire with income nearly equal to their top salaries.

Meanwhile, the district has underfunded the pension plan. As a result, it has only 65 percent of the funds it should, with a shortfall of $535 million.

Moreover, employees bear only a small portion of pension costs. The total contribution to fund the pension plan is officially 45 cents for every dollar of payroll. Of that, the district pays about 38 cents and employees pay about 7 cents.

Retiree health care: The district offers its employees a retiree health care plan. By public sector standards, it's modest, paying a flat $450 a month for single retirees or $550 for those with a spouse.

But the district has badly underfunded it and has required almost no contributions from employees. As a result, the retiree health care plan has only 14 percent of the money it should, with an $89 million shortfall.

Unfunded liability: The shortfalls for the pension and retiree health programs total $624 million. To put that in perspective, it equals about four years of base salaries for all district employees.

That's debt for past labor costs dumped onto future taxpayers and ratepayers. We're already seeing that intergenerational transfer of debt. Installment payments on the unfunded liability are a major contributor to annual pension costs, which have increased 68 percent since 2008.

What's worse, the pension liability is based on the optimistic assumption that the retirement plan will earn 7.75 percent average annual returns on investments far into the future. If that assumption were lowered, as many pension plans have done, the unfunded liability and the annual payments would be even more.

Before the district raises rates, it should give those paying the bill full information and ensure they won't be the only ones bearing the burden.

Daniel Borenstein is a staff columnist and editorial writer. Reach him at 925-943-8248 or dborenstein@bayareanewsgroup.com. Follow him on Twitter.com/BorensteinDan.