Stephen Goldsmith is deputy mayor of operations for the City of New York.

Even a decade later, I still recall a conversation I had as the mayor of Indianapolis with a regional Environmental Protection Agency (EPA) official about the challenges of dealing with combined sewer overflows (CSO). I asked him if the measure of our success would be how clean the river was or how much money we had spent reducing the overflows. He admitted it would be the latter.

While citizens today care about a green, sustainable environment more than ever, too often regulators pursue unthinking enforcement without regard for the level of public health risk and cost. City officials have quite a different perspective. Every day we have to deal with competing risks and public needs with limited tax dollars.

Today, as deputy mayor of New York, it is my job to execute Mayor Michael Bloomberg's commitment to going green. We pay attention to everything that impacts the environment -- how we build, how we make transportation decisions, how we produce clean water and dispose of waste.

Green is not free, however. We have to make public decisions with an eye toward how to accomplish our environmental goals in a way that compliments and does not threaten essential services. If we prematurely commit to expedite expensive school renovations in order to mitigate against "risks" that aren't risky at all, that $1 billion expense would result in layoffs for teachers.

Federal officials don't experience the other side of this equation. They can accomplish their environmental goals at our expense without considering the cost. They have the authority to mandate a project without funding it. They can dictate when and how a project will be built, dictate specific milestones and impose draconian penalties if those milestones are missed. When the feds accomplish their own priorities by making local governments pay for it, it distorts priorities and freezes innovation.

For example New York City's Department of Environmental Protection Commissioner Cas Holloway has proposed a way to address the city's CSO issue. Instead of the expensive underground infrastructure to hold stormwater, Holloway presented a detailed green infrastructure plan that captures runoff through a variety of approaches, from planting tree boxes to creating more permeable surfaces. This approach could save more than $2 billion while improving both water quality and New Yorkers' overall quality of life.

But New York City must wait for approval from its state regulator, just as other municipalities, such as Philadelphia, have waited for years for approval from the EPA to adopt this innovative approach.

The EPA has an important environmental mission. Ironically, the rule-based manner in which it approaches this mission often erodes the environment. It hampers innovation. Instead of thinking of how they can go green for less, local governments are jumping through expensive hoops.

Since 2002, Mayor Bloomberg has committed $19 billion to water and wastewater infrastructure. Of that amount, $14 billion -- nearly 70 percent -- has been for investments mandated, but unfunded by the federal or state government.

When the federal government forces a locality to spend billions of dollars on something that has no public health benefit, it is indirectly forcing the layoff of public employees, or higher taxes and water rates on residents struggling to prevent foreclosures.

That scenario has been unfolding in New York City since the EPA promulgated the notorious Long Term 2 Enhanced Surface Water Treatment Rule (LT2) in 2006. Under the rule, New York must install a cover over the 90-acre Hillview Reservoir in Yonkers, a project that will cost $1.6 billion or more. The stated purpose is to protect Hillview water from contamination by certain pathogens, but the reservoir, which sits on top of a hill, has never been exposed to these pathogens, as thousands of test results show year after year.

It gets worse. Just 15 miles north of Hillview, New York will begin operation of another mandated investment -- a $1.8 billion ultraviolet disinfection plant -- that will treat the city's water for the same types of pathogens that the Hillview cover is intended to prevent.

Environmental spending should produce proportionate environmental and public health results. An executive order from President Obama on regulatory reform may help accomplish this. It directs federal agencies to review their regulations in a way that "must take into account benefits and costs." Applying this order to the EPA would produce a greener environment in a more affordable way.

Last week, EPA administrator Lisa Jackson testified that she is "accountable for ensuring that [EPA] squeeze[s] every drop of public health protection out of every dollar [it is] given." It's a laudable goal. To do it, the EPA must allow local governments to use innovative, cost effective environmental solutions.

Which takes me back to Indianapolis, which has been struggling under a mammoth EPA-imposed $4 billion combined sewer overflow mandate and has been pleading for permission to implement a much more creative and effective solution. The EPA regional office, assuming that expense equaled value, originally objected to this proposal because it was less costly and could save hundreds of millions of dollars for the city's urban residents.

The goal of a clean environment is laudable. But public health benefits and costs have to be part of the equation, as does a regulatory environment conducive to creativity and innovation.