The same treatment for all.

That’s the basics of a legal argument that potential waterfront developers Nancy Josephson and Steve Day have presented to Langley officials in recent weeks.

Langley has been considering changes to its rules on shoreline development amid complaints from property owners that development rules are too restrictive for properties near the Wharf Street bluff.

In a letter sent to the city in January, Josephson and Day warned city officials that Langley may face a legal challenge if the city continues to treat commercial property owners in the marina area differently than the way the city has dealt with property owners on First Street.

Mayor Paul Samuelson said the city believes it is on solid ground with the way the waterfront is treated, however.

“The city feels real clear that there are two different situations. One area is quite different from the other,” Samuelson said.

City officials have not asked Langley’s legal staff to review the issue.

Currently, property owners along First Street are exempt from “critical areas” regulations that prohibit development along steep slopes. Property owners who own land on nearby Wharf Street, however, have repeatedly asked for the same outright exemption so their properties near the marina can be developed or sold.

While none of the landowners near the marina, or the developers who have started work on development plans there, have publicly threatened a lawsuit, some have continued to insist that First Street property owners are getting preferential treatment.

Commercial properties on the north side of First Street were exempt from the city’s critical areas ordinance years ago. That has made it easier for landowners to remodel or build on the bluff within the 50-foot buffer that would otherwise be a no-build area.

But what’s needed, property owners near the marina have said, is an extension of the critical areas exemption from First Street properties to Wharf Street properties. While a volunteer board recently reviewed potential changes to the development rules, the group stopped short of recommending that the city council extend the same exemption enjoyed by First Street property owners to lands a bit further up the coast.

Landowners have made repeated requests for the city to resolve the issue.

Josephson and Day, the two developers who want to build a terraced mixed-use complex on the bluff between the shore and Cascade Avenue, have sent Samuelson two separate letters on the topic that detail their concerns.

The first letter — 20 pages long with another 12 pages of attachments — was sent Jan. 8.

In it, Josephson and Day wrote that giving property owners along First Street an exemption but leaving Wharf Street-area properties out “constitutes an unequal and arbitrary application of the law.”

“As a general legal principal, owners of commercially-zoned slope parcels in this area should not be forced to navigate greater permitting obstacles (or be otherwise disadvantaged under the law) in comparison to First Street property owners,” they wrote.

In a letter to council members sent before he left office, former Mayor Neil Colburn said that treating the two areas of the shoreline differently was unintended.

The original committee that helped write Langley’s growth plan had not intentionally omitted the marina area from the First Street exemption when it was created, he wrote in the Nov. 8 memo to the council.

“The omission (of the marina area) was simply a failure of imagination that existing structures based at the base of the bluff below Cascade Avenue would someday be replaced or these properties improved,” Colburn wrote.

Colburn said in the memo the commercial properties on the north side of First Street were exempted from the critical areas ordinance so existing structures could be improved or replaced as circumstances warranted. That meant structures could be built on the bluff within the 50-foot buffer otherwise required by steep slopes.

Developers with plans near the Langley marina have repeatedly floated the idea off building into the bluff, or within the 50-foot no-build buffer at the top and the bottom of the slope.

Colburn said in the memo that the code should be changed so the properties below Cascade Avenue and First Street are treated equally.

Josephson and Day, in one of their letters, suggested extending the exemption to the properties in the marina area, as well, or removing the exemption from First Street properties.

Steve Day, who is also a lawyer in addition to being an architect and developer, said the city did not have a scientific basis for putting different regulations on similar properties.

The city would expose itself to legal claims if it arbitrarily imposes greater regulatory burdens on one group of commercial property owners versus another group of similarly-situated commercial properties, Josephson/Day wrote.

The pair said the existing exemption should remain in place on First Street so property owners can continue to maintain their properties. They also pointed to a petition signed by 135 Langleyites who supported seaside development that would help the local economy.

Langley’s Planning Advisory Board reviewed potential changes to the rules earlier, and suggested a minor change to allow Wharf Street property owners the chance to improve their existing structures and build within the historic setbacks on their properties.

On the First Street side, they suggested revising the existing exemption to further restrict development based on community feedback.

The board did not suggest a blanket exemption for the entire waterfront.

The city council will likely review the Planning Advisory Board’s recommendations sometime this month, said Councilman Robert Gilman.