The recent boom in unconventional natural gas (UNG) production from the Marcellus Shale Formation in Pennsylvania has brought challenges of how to treat the large volumes of wastewater produced during drilling and hydraulic fracturing. In the late 2000s, capacity at permitted wastewater treatment facilities was quickly overwhelmed. Drilling companies began sending their wastewater to Publicly Owned Treatment Works (POTW) that were not designed or permitted to treat wastewater high in Total Dissolved Solids (TDS) and chloride. Recognizing the need for wastewater effluent standards that specifically targeted TDS and chloride, the Pennsylvania Department of Environmental Protection (DEP) added new effluent standards under 25 Pa. Code Section 95 in August 2010. The new effluent limits for TDS and chloride were set at 500 mg/L and 250 mg/L, respectively. Under 25 Pa. Code Section 95, facilities permitted to treat oil and gas wastewater prior to August 2010 were exempt from the new effluent limits. Although much progress has been made in reducing TDS and chloride loads from UNG wastewater through regulation and voluntary agreements, the exemption in 25 Pa. Code Section 95 still exists for conventional oil and gas drilling wastewater, allowing the continued discharge of TDS and chloride at hundreds of times greater than the new limits. An overview of Chapter 95 is provided along with two case studies of wastewater treatment facilities that highlight the regulatory successes and failures in reducing TDS and chloride discharges to Pennsylvania's rivers.