Great Bay Regulatory Improvement Act of 2015

This bill directs the Environmental Protection Agency (EPA) to postpone for five years establishing water quality standards or effluent limitations under the Federal Water Pollution Control Act (commonly known as the Clean Water Act) if those standards or limitations reduce nitrogen discharges into the Great Bay Estuary. That estuary extends from the mouth of Portsmouth Harbor, in the vicinity of Portsmouth, New Hampshire, to the head-of-tide for the eight rivers (including the tributaries of those rivers) that flow into Great Bay, Little Bay, and the Piscataqua River.

During that five-year period, the EPA may not require a publicly owned treatment works (POTW) to commence construction on any upgrade of a facility for the purpose of enforcing those standards or limitations if the POTW contributes nitrogen loadings in that estuary.

The EPA must study eelgrass levels and the causes of any loss of eelgrass habitat in the Great Bay Estuary, and allow public participation in the development of the study.