Wareham sewer users currently pay a flat rate annual fee regardless of sewer usage. That could change after the full results of a study from a local environmental group.

Michael Schrader, from the Pocasset-based engineering and environmental consulting firm Tighe and Bond, gave a presentation to Selectmen on Jan. 14 reviewing the work his firm has done thus far on the study. Selectmen commissioned Tighe and Bond to conduct the study at a meeting last May

He spoke about the differences between communities paying a flat fee, like Wareham, and usage-based fees that many other municipalities are shifting toward.

Currently, residents pay the same flat fee of $569 per property per year, according to the number of EDUs (equivalent dwelling units) assessed to a property. For example, a single-family home would be charged one EDU, while a two-unit duplex would generally be charged two EDUs.

"The EDU rate has always bothered me it's always been a problem. Right now, the way we go out there and reapportion some of these EDU rates is a catastrophe to some businesses and people," Selectman Patrick Tropeano said. "I think we should have a minimum rate, like they do with the water and then charge by the flow."

Schrader said the pros of using the flat fee EDU system are the convenience and the steady revenue it supplies, but a con is that the way EDUs are assessed may not be fair to everyone in the community. Schrader gave an example of a business that could be classified at one level of sewer usage, then the next year switch to barreling all their waste, or enacting any other number of changes that affects their usage but not their payment.

He then explained the alternative, a flow-based rate structure. This is system is much more fair and accurate because each user would be billed by a measurement of discharged sewage, according to Schrader.

Tighe and Bond collected sewer data from 202 towns out of 351 across the state and Schrader said 11 percent of the towns surveyed use the flat fee system Wareham does.

"Everybody is going away from that system. Eleven percent is a very small number," Tropeano said. "I wanna see more equity in the system. EDUs are not equitable."

Schrader said 59 percent of the town, or about 6,150 customers, is sewered and there is a 55 to 36 percent spilt between Wareham and Onset.

Nine percent have sewer access but use well water, and Schrader said, "That's something you'll have to set policy on to decide what is a fair way to assess their waste water usage."

Schrader also said a possible drawback to the usage-based system is the increased complexity, especially in Wareham where there are two independent water districts. He said gathering compatible data from both organizations could pose a challenge.

Selectman Peter Teitelbaum said the next step for Selectmen will be gathering more data and hosting workshops on the topic.

"This is not something that will be decided over night," Teitelbaum said.

He said the board is see what options are fair, if there is reason to change, what the costs and consequences of those changes would be and what the best approach will be going forward.

He said the board would give notice about workshops on the matter in the near future.