Activist Tina Motley-Pearson and other environmentalists have been watching the lake, and worrying about it, for years.
"Most of the pollutants are coming out of Durham," she told ABC11 Eyewitness News. "At some point, somebody has to be accountable - at some point. And, it's a shame that the water users are the ones that suffer."
Motley-Pearson says the issue goes back decades. Each time it comes up, she says Durham fights for its right to keep developing, but more development means more erosion, more runoff, and more problems, she says, for Falls Lake and for everyone downstream.
"Raleigh is not getting their fair shake in this," she told ABC11.
To help define Durham's role in cleaning-up the lake, it hired Raleigh lawyer Steve Levitas as a lobbyist. He is an expert in state environmental law. A few years back, he was second in command at the NC Department of Environment and Natural Resources.
Durham Deputy City Manager Ted Voorhees says hiring Levitas makes sense for the city.
"We're using his skills and knowledge to develop the most balanced approach to deliver value to our taxpayers," he explained.
But some environmentalists say 'balanced' means weaker environmental rules that will cost Durham taxpayers less money. They question the hiring of a former state official as a lobbyist.
"They're excellent resources for polluters to hire to fight rules because they understand all the loopholes," said Motley-Pearson. "I find it very, really, quite horrible that Steve Levitas, who considers himself an environmentalist, to work so hard to gut these rules."
But Durham leaders that's not the case.
"There are aspects of the rules that have been drafted that we take issue with and that don't appear to deliver any real results and Steve's expert knowledge of how to craft rules and regulations is essential to figuring out a balanced approach," said Voorhees.
Voorhees' name is at the top of a city memo recommending that $120,000 be set aside to pay Levitas. The money comes from storm water fees.
But critics say those funds are meant for storm water services such as those laid out on the city's website - things like drainage maintenance, stream monitoring, and pollution prevention.
Environmentalists, including Wakeup Wake County director Karen Ringe, see a direct contradiction.
"Storm water fees are public funds that are supposed to be used to improve water quality. If they're using those funds to hire attorneys to in fact weaken water quality, that's a problem. It's a problem for the public and it's a problem for those of us that are drinking the water.
But Voorhees is resolute.
"If it's within the letter of the law, is it within the spirit of the law to use storm water fees to pay for Mr. Levitas's services?" asked ABC11 I-Team reporter Jon Camp.
"Absolutely," Voorhees responded.
"How can you say that when there is a fairly apparent contradiction here?" Camp asked.
"I see no contradiction whatsoever in trying to develop a balanced and appropriate package of rules and regulations," said Voorhees.
And unless the state takes issue with Durham's use of taxpayer money, Levitas will likely stay on the payroll working toward a balanced solution. Balance, perhaps, depending on your perspective.
ABC11 talked at length with Levitas about his role in the clean-up of Falls Lake. He said he's helping craft "responsible environmental policy" that also makes sense financially. He said any suggestion that he's not concerned about the environment is a "mischaracterization."
Ultimately, the rules that will be put into place will have to be approved by the Department of Natural Resources - Levitas's former employer - before they can begin to be implemented.