Imagine six acres of waterfront property zoned for development but sitting empty for more than 20 years and generating no revenue for the city. That is the reality for a site at Fort Trumbull where RJ Development + Advisors LLC wants to build 500 housing units that will generate millions in revenue for the city in addition to new customers for our business community.

There are strings attached to this opportunity, of course. And those strings will unbind this property from the restrictions that have sent nearly a dozen other potential developers running from this land for the past 20 years.

The property in question, known as parcels 1A and 3C on Fort Trumbull, totals 6.5 acres. This city-owned land, along with other sites in Fort Trumbull, has remained undeveloped following the debacle of the infamous Pink House eminent domain case that landed with the U.S. Supreme Court in 2005.

Those strings are partial tax deferrals for 20 years intended to offset the extraordinary expenses associated with developing this land based on site conditions that have chased at least eight other developers away from these waterfront sites, specifically:

* These two parcels along the Thames River sit in the 100-year to 500-year flood plain and therefore are limited in use.

* Some areas of the property remain contaminated though other areas were cleaned. Remediation standards have increased in the past five years, adding even more to the cost than previous developers faced – on the order of $500,000 versus $4 million.

* When the site was cleared of houses, basements were simply collapsed and filled with building rubble, leaving a substrate unsuitable for building.

RJ Development + Advisors has shown that they – and any other developer – will incur significant costs, estimated at $12.7 million more than at a site without these issues, specifically:

* The state Department of Energy and Environmental Protection (DEEP) requires housing on these properties to be built above the 500-year flood plain. This level of elevation will add significantly to design, engineering, materials and labor costs.

* Cleaning areas of contaminated soil that were not cleaned by the now-defunct New London Development Corporation will add costs.

* Addressing the substandard soil conditions will require expensive engineering controls or significant soil replacement, adding to costs.

It is vital for residents to understand that any developer will face these extraordinary expenses. RJ Development + Advisors, which has already provided the city with additional housing and tax revenue with its Beam property on Howard Street, chose to work with New London and DEEP to bring these parcels back to life.

The proposed tax deferral, which I wholeheartedly endorse, needs the support of the New London City Council and I urge the council to approve this proposal.

The city will collect taxes once a certificate of occupancy is approved – the first tax collection on this property in more than two decades. In the first year after completion, we will collect 20 percent of the assessed value. In the second year we will collect 40 percent, and in years three through 20 we will collect 60 percent of the assessed value for an estimated total of more than $18 million over that span. After 20 years, we will collect the full taxable amount annually.

We will be giving up $6.5 million over that time frame to partially offset the nearly $13 million in extra site expenses – expenses that have derailed other projects and resulted in no revenue for more than 20 years. In essence, RJ Development + Advisors is asking us to split the extra development costs. Other developers, eyeing the nearby Electric Boat workforce as a prime customer and the waterfront as a prime amenity, still walked away based on these additional expenses.

It would be irresponsible for us to walk away from millions in tax revenue, additional housing badly needed and more customers for our business community.

Michael Passero is the mayor of New London.