Last Sunday I stood on the porch of our office on East Bay and was enveloped in exhaust from Carnival Fantasy. Leaving work the next day, I was diverted from Concord Street to a gridlocked intersection at Hasell and East Bay, courtesy of the Carnival Glory. Both events were not-so-subtle reminders that the cruise ship discussion in Charleston remains unresolved.

This debate began in earnest last January at the Historic Charleston Foundation's forum called "A Delicate Balance." We and others have raised legitimate concerns about air and water pollution, about damage to Charleston's reputation as a high quality visitor destination and about a decline in the city's quality of life.

To date, the S.C. State Ports Authority has failed to respond substantively to any of these issues. As a public agency, the SPA has an obligation to address these concerns honestly and comprehensively. It is also essential that the city act to protect its hard-won national reputation and the quality of life that make Charleston unique.

First, unless we are willing to accept three, four or five ships a week, Charleston must adopt a cap on the number of annual visits. There are 3,346 hotel rooms on the Charleston peninsula. The Fantasy has more than 1,000 cabins for passengers and crew. This represents almost one third of all land-based rooms. Our city vigorously debates the addition of even a 50-room hotel. It is almost inconceivable that we would fail to control the number of additional rooms from cruise ship visits.

The cruise ship industry has a poor record of environmental compliance and the two lines calling on Charleston, Celebrity and Carnival, are among the worst performers. For this reason, voluntary environmental standards will not work. It is up to the city to impose adequate and reasonable pollution safeguards.

Anyone who lives on the East Side is familiar with the soot that coats porches and windows. The primary sources of these toxic compounds are the cargo and cruise ships at Union Pier and container ships at Columbus Street. We should make every effort to reduce all emissions by requiring cleaner fuel and providing shoreside power.

The SPA has presented information that is, at best, confusing, suggesting that international regulations prohibit sewage discharges closer than 12 miles. But these regulations, called Marpol Annex IV, have not been ratified by the United States and are not in effect in this country. The regulations that do control cruise ship discharges in U.S. waters allow treated sewage to be dumped within three miles of shore, including in the harbor. Untreated sewage can legally be discharged beyond three miles. This leaves only the cruise lines' voluntary commitment to protect our harbor and near-shore waters.

The SPA commissioned two College of Charleston economists to study the economic impacts from cruise visits. The study projects a total impact of $37 million in 2010.

The most important deficiency of the study is that it looks only at revenues and ignores the costs to the city. These include traffic congestion and delays for residents, traffic management costs, air and water pollution, and the damage large-scale cruise operations can do the Charleston's "brand" and our overall tourism economy.

This is a real cost, as National Geographic Traveler's destination ranking demonstrates. Unlike Charleston, which currently ranks in the top category for the quality of a visitor's experience, National Geographic Traveler assigns Key West and St. Thomas the lowest rating specifically because they are overrun with cruise ships.

Another problem with the SPA's study is that it attributes a large proportion of the economic impact to ships restocking in Charleston. Yet the companies providing this service are virtually all out-of-state.

The study reveals that more than one third of all spending in 2009 went straight to the SPA in the form of fees. These fees are not likely to flow back into the local economy. Further, as a state agency, the SPA does not pay local property taxes or state income taxes, depriving the city and county of millions of dollars annually that would otherwise be contributed by a private company.

Finally, unlike most cities with a large cruise business, the City of Charleston receives no fees from the ship visits. So we believe the positive economic impacts of cruise ships are less than the report claims, and we are certain that costs, even those that are difficult to quantify, should be included in any objective analysis.

In January we met with SPA president Jim Newsome and other agency officials to discuss these issues. We offered to work with the SPA to establish reasonable environmental standards for cruise ships and presented a list of recommendations to consider. At that meeting, Jim told us that they would oppose all of the recommendations. When we asked for their rationale for rejecting the suggestions, he agreed to provide it in writing. Four months later we've received nothing.

We subsequently asked for information on a variety of issues, such as garbage collection facilities at the dock and financial projections for the proposed Union Pier project.

In every case, SPA employees either promised to provide the information and then failed to deliver it or refused our request outright. We have, consequently, been compelled to invoke the Freedom of Information Act for things that should have been made freely available.

Charleston is justifiably proud of the high bar we have set for architecture and design. We have a golden opportunity to set a comparable standard for cruise ships, where air and water will be protected to the greatest extent possible and the quality of life of this 300-year old settlement will be sustained.

It is unfortunate that the SPA has adopted a hard-line attitude of non-cooperation and defensiveness. It would be a grave mistake if we allow Charleston to be damaged and degraded because of their intransigence.

Dana Beach is executive director of the Coastal Conservation League.