The biggest environmental concern in the Pine Barrens is not so much the land but what is under it - a huge, giant aquifer, built from thousands of years of rainfall passing through the near totally sandy soil. The “threat” to that from a natural gas pipeline is minimal and easily mitigated.
Water from the aquifer is some of the cleanest, purest in the nation (if not the world). As you stated, the sandy soil has filtered it to an amazing degree. Those on well water have some of the purest and best tasting drinking water available.
The pipeline won't pose any hazard to that, as you stated.