Homebuilder D.R. Horton plans to notify hundreds of North Carolina home buyers next week that they have until Sept. 28 to get back the mineral rights the company took from their properties.

The Texas company will require that North Carolina home buyers submit a written request by the fast-approaching deadline if they want their mineral rights back. The timing will give customers about one month to respond or waive their mineral rights through inaction.

D.R. Horton's latest step to defuse a simmering controversy continues to trouble state regulators. One issue: Inconspicuous envelopes could be misplaced by the customer or mistaken for junk mail and thrown out. The N.C. Attorney General would like that at the very least, the envelope to be clearly marked as urgent and requiring a prompt reply.

D.R. Horton is under investigation by state AG and N.C. Real Estate Commission after the company kept for itself mineral rights from 850 homes it sold in the state in the past several years.

The two agencies plan to discuss problems with D.R. Horton's draft letter with the company, but state officials have said they don't have the legal authority to force the company to restore the mineral rights to customers.

State officials have told D.R. Horton they would prefer for the company to return the mineral rights, rather than placing the burden on customers.

"We can't order them to do anything," said AG spokeswoman Noelle Talley. "One of the options, we've said, is they can just give the mineral rights back."

The state Attorney General's office estimates that around 400 to 500 homes have been sold in North Carolina in recent years stripped of legal rights to drill and frack for natural gas under the properties.

The homebuilder, D.R. Horton, this week notified state officials it would return those rights to any homeowner who requests it. The company did an about-face amid a public outcry and twin state reviews of its practice. Many of the affected homes were sold throughout the Triangle.

D.R. Horton's policies of systematically stripping drilling rights is under review by the state AG's Consumer Protection Division and by the N.C. Real Estate Commission. Both agencies are now tracking the builder's offer to return mineral rights to customers who make the request.

At this point it remains unclear how long the offer to return mineral rights will be available and how many D.R. Horton customers are aware of it.

Experts on mineral rights and other aspects of energy exploration will discuss the ins and outs of negotiating land leases tonight at a workshop in Durham.

The fracking event will be held at 6 p.m. at the Durham County Extension Office at 721 Foster Street. It's free to the public.

Fracking refers to hydraulic fracturing, a technology used in conjunction with horizontal drilling to tap into underground natural gas deposits trapped in shale rock formations. North Carolina is believed to have about 40 years of shale gas around Lee, Chatham, Moore and other central counties.

Such drilling practices are not currently legal in this state but they are likely to be debated by the state legislature.

Speakers will discuss legal considerations and other factors to consider when negotiating a lease, among other related topics.

State officials and property-owner advocates will conduct an informational session tonight to help landowners negotiate lease offers with energy exploration companies.

Previous sessions on this topic in the past year had packed attendance as farmers and other landowners seek guidance on signing mineral rights contracts with companies that want to drill for natural gas on their land.

Drilling companies have contacted hundreds of residents in Lee and Chatham counties, where underground natural gas reserves are believed to be concentrated. State geologists estimate that the shale gas deposits contain enough fuel to supply the state for four decades. 

Some are concerned that residents are signing away their property rights for a fraction of their value and signing contracts that hold landowners financially responsible for spills or other environmental accidents on their properties.