The United States Environmental Protection Agency modified proposed rules regarding the replacement of engines in water well drilling rigs to allow for rigs up to 40 years old.

"The revised rule is a major improvement over EPA's previous proposal," said Denis Crayon, the National Ground Water Association's DOT-OSHA subcommittee chairman.

Initially, the proposed rules required Tier-4 compliance for engine replacements in rigs older than 25 years. NGWA says about 30 percent of rigs working in the field would have issues meeting those requirements. Pushing the requirement back to 40 years significantly reduces the number of rigs affected by the final rule.

"Through photos and other communication, NGWA was able to explain the inability, in some cases, to switch out old engines with new Tier-4 engines, and maintain transportation and drilling capability," said Fred McAninch, who's professionally known as the "Rig Doctor." McAninch also sits on the group's DOT-OSHA subcommittee.

As many drillers know, and the NGWA reiterated to the EPA, it's not unusual to see equipment older than 25 years still in use in the field.

"We are very pleased that the agency worked with NGWA to revise its final rule so as to advance our mutual goals of improving air quality and meeting the nation's water supply needs," Crayon added. The group says the revised rules will allow the water well drilling industry the flexibility to improve air quality while maintaining business operations.

NGWA applauded the federal rules change, but encouraged drillers to consult rules for individual states, such as California, for any additional regulations. See a copy of the federal rules here.

NGWA is a nonprofit that supports responsible development, management and use of water resources. It’s comprised of groundwater professionals ranging from contractors to equipment manufacturers to scientists and engineers. For more information, visit