Wastewater Treatment Works Security Act of 2005

Wastewater Treatment Works Security Act of 2005 - Amends the Federal Water Pollution Control Act to authorize the Administrator of the Environmental Protection Agency (EPA) to provide grants to a wastewater treatment works, state, municipality, or intermunicipal or interstate agency to: (1) conduct vulnerability assessments of wastewater treatment works; (2) prepare and implement site security plans; (3) prepare emergency response plans; (4) implement certain security enhancements and alternative approaches to wastewater treatment to reduce security threats; and (5) obtain technical assistance.

Requires the Administrator to: (1) issue regulations to require owners or operators of wastewater treatment works to conduct vulnerability assessments and to implement and submit to the EPA site security and emergency response plans for treatment works; and (2) establish confidentiality protocols to protect information submitted by such owners or operators.

Authorizes the Administrator to: (1) provide technical guidance to small wastewater treatment works (serving a population of fewer than 10,000 people) on conducting vulnerability assessments, preparing emergency response and site security plans, and implementing security enhancements; (2) make grants to nonprofit organizations to improve vulnerability assessment methodologies and tools for publicly-owned treatment works, including those that are part of a combined wastewater treatment and water supply system; and (3) designate substances of concern based upon the threat from an unauthorized release from a treatment works.

Requires the Administrator to research and review terrorist threats to wastewater treatment plants and alternative means for providing wastewater treatment in the event of attacks on such treatment plants.