HOUSTON (AP) — The Texas Parks and Wildlife Department has embarked on an environmental study to monitor the effects of oil and gas drilling on the springs that feed a famous pool at Balmorhea State Park in West Texas.

Brent Leisure, the state parks director, tells the Houston Chronicle (http://bit.ly/2rku52o ) that he could not remember ever launching a similar effort in another of the state's 95 parks, historic sites or natural areas. Parks biologists, hydrologists, geologists and administrators have mounted an in-depth, multiyear effort to monitor plants, fish, insects and water.

"We have a...