Mayoral candidate and state Sen. Anthony Hardy Williams' campaign website contains a fairly detailed "Issues" section, with one exception — it lacks any stance on environmental issues.

His wife, Shari Williams, however, has quite a robust stance when it comes to Mother Nature, but one that isn't likely to please many environmentalists.

As a highly paid executive with a preeminent gas-drilling advocacy group, she writes essays for an industry magazine, extolling the virtues of what is commonly referred to as "fracking," and advocates a vision of Philadelphia as a major oil- and gas-processing hub.

"Although southeastern Pennsylvania currently is home to few shale rigs, the region is vital to the continued growth of the safe development of natural gas," she wrote in a 2014 column for MQ (short for Marcellus Quarterly). "To truly reach its potential, the industry needs the support of communities in SEPA that see its significance and will feel the benefits."

A former communications specialist for the Pennsylvania Utilities Commission, a regulatory body that oversees aspects of the state's gas industry, Shari Williams now makes $112,000 a year working as a community outreach manager for a fracking industry organization called the Marcellus Shale Coalition (MSC).

MSC is regarded as an "astroturf" group, built to rebut environmental criticisms of fracking and push positive stories about the gas industries' economic successes, while organizing "grassroots" support for fracking with a pile of industry money.

The oil and gas industry spent some $41 million dollars lobbying Pennsylvania officials since 2007, according to a 2014 report by the Marcellus Money Project. More than $11 million came from MSC.

Her lucrative position at MSC has led Shari Williams to take some other positions on gas extraction in Pennsylvania potentially uncomfortable to her husband. She's criticized a popular plan to impose an excise tax on fracking companies, which has become a cornerstone of Gov. Wolf's educational funding strategy.

Pennsylvania is one of the only states in the nation without such a levy, and various plans for an excise tax have received bipartisan support in Harrisburg. But in November, Williams tweeted, "Additional energy taxes would stifle production and kill good-paying, long-term jobs," followed by "#JobsNotTaxes."

Williams then linked to an industry produced commercial that describes any form of energy taxation as a job killer.

In another tweet, she wrote, "Get the facts[,] taxes are paid, don't let them fool you," linking to an MSC infographic outlining, among other things, the environmental-impact fees that are already paid by fracking companies.

Those fees were imposed by what became known as Act 13 in 2012, in response to the increasing environmental disruption caused by the fracking industry upstate. Her husband was one of just four Senate Democrats to vote for the bill, which drew widespread criticism from environmentalists for its paltry fee structure and threadbare environmental protections. Shari Williams landed her job at MSC six months after that contentious vote.

Shari Williams said Thursday that she and her husband do not talk drilling or tax policy related to Pennsylvania's fracking industry.

"I have not spoken to him about adding a severance tax to an already taxed industry," Shari Williams said. "I'm just a wife and my husband is running for another office. I'm supporting him."

She added that she didn't even know he voted for Act 13.

"He doesn't come home and say, 'I voted for this today,'" she said.

Sen. Williams said through a spokesman Thursday that he was committed to advancing the same vision of Philadelphia as an energy hub often mentioned in his wife's writing, though he did not refer specifically to Marcellus Shale drilling.

"Sen. Williams strongly supports the development of Philadelphia as an energy hub, as the best way to transform the city's economy and add thousands of family-sustaining jobs for Philadelphians from all walks of life," campaign spokesman Al Butler wrote in an e-mail.

But the spokesman skirted questions about Shari Williams' influence on her husband.

"Do he and his wife discuss the issue? Of course, but his support for the hub is entirely his own, largely because of estimates that suggest that 63 percent of all jobs created in the energy space will be blue collar, requiring a high school diploma and some training," he said.

Steve Hvozdovich, Pennsylvania campaigns coordinator for environmental group Clean Water Action, said that the next mayor of Philadelphia will have to deal with the fact that thousands of oil trains passing through Philadelphia have brought fracking's environmental consequences closer to home.

"[Williams] has shown himself to be someone who can be supportive of the environment but there's reason to wonder going forward if his wife could have an influence on some of his positions as they relate to energy production," said Hvozdovich. "He should start talking about these issues publicly. Having something on his 'Issues' page would certainly help him defuse some of the uncertainty on whether his wife's position might have on his positions."