Hey, the scene in question actually led to a lawsuit. Turns out that the hose was actually attached to a gas release valve (that are typical in off grid water pumps).
This news article does a good job reporting on it.
http://www.washingtonexaminer.com/gasland-scandal-ignited-at-epa/article/2532966
HBO viewers thought they saw Steve Lipsky, a Parker County, Texas, home-owner, holding his garden hose belching fire from his methane-contaminated water well. The flaming water was terrifying and "Gasland Part II" blamed it on fracking done by Range Resources, a Fort Worth-based shale gas driller.
What viewers actually witnessed was Lipsky holding a hose secretly connected to a gas vent, not a water line. This fraud came out in a lawsuit filed by Steven and Shyla Lipsky against Range for $6.5 million in the 43rd State District Court of Texas. The Lipskys claimed two Range natural gas wells contaminated their water well with methane.
Here's court documents (longer read).
Rich and the Lipskys Enter Into a Conspiracy to Defame Range.
While the TRRC investigation was underway, Mr. Lipsky had conversations with Rich in which he discussed wanting to contact the news media “to get Range to do something.” [5 CR 1443]. Rich is an environmental “consultant” who has a history of dishonesty and using false or misleading information to support her bias against oil and gas drilling, including manipulating “evidence” and publicly misrepresenting her credentials.12 [2 SCR 646, Tab C, Slide 13; 7 CR 2150-51; 5 CR 1221, 1224-25, 1382-84]. In an August 12, 2010 email to Mr. Lipsky, rich outlined a “strategy” in which she proposed staging a deceptive air test designed to create a non-existent imminent danger of explosion. *[5 CR 1243; App. E]. The strategy also involved making and disseminating misleading videos purporting to show flaming water from a green water hose attached to the Lipskys’ water well.13 The green hose actually was attached to the gas vent on the water well as shown below.14