CLEAN WATER
Everyone needs clean drinking water. All living creatures depend on clean water in streams and lakes for health and happiness…not to mention survival. That’s why the Pennsylvania Turnpike thinks a lot about how we handle stormwater runoff that comes from our roadways, service plazas, interchanges and other facilities.
When precipitation falls, it doesn't sit there, it starts moving according to the laws of gravity. Some precipitation seeps into the ground to replenish groundwater. Some of it also flows downhill as runoff. Runoff occurs during storms, and more surface water flows in streams (and as runoff) during storms.
As it flows over land, stormwater can pick up pollutants like sediment (dirt), nutrients (from lawn and farm fertilizers), bacteria (from animal and human waste), pesticides (from lawn and garden chemicals), metals (mining and industrial sources) and petroleum byproducts (from leaking vehicles).
Runoff from agricultural land (and even our yards) can carry excess nutrients like nitrogen and phosphorus into streams, lakes and groundwater supplies. These excess nutrients can also degrade water quality.
The Pennsylvania Turnpike’s initiative to reduce pollutants in stormwater during construction activities is achieved through its Erosion & Sedimentation Control measures, and in a perpetual manner through Post-Construction Stormwater Management for roadway and facility expansion. These initiatives are guided by the National Pollutant Discharge Elimination System (NPDES) program administered by the Pennsylvania Department of Environmental Protection (PADEP) and Environmental Protection Agency (EPA). Additional details on the Turnpike’s stormwater initiatives are outlined below.
Erosion & Sedimentation Control
The Pennsylvania Turnpike Commission is committed to ensuring that sediment in construction site stormwater runoff is controlled by following local, state, and federal NPDES program and permit requirements. Land development and roadway reconstruction activities often remove vegetative cover and expose soil making the site more susceptible to erosion from storm events. To mitigate the impacts of sediment entering waterways, Erosion and Sedimentation (E&S) Best Management Practices (BMPs) are implemented and maintained throughout the course of construction until the vegetative cover is restored, and erosion potentials have diminished. BMPs are temporary structural or vegetative practices that are designed to trap or filter sediment in stormwater runoff prior to leaving the construction site. BMPs require site-specific design, routine inspection, and maintenance to ensure that they are functioning properly throughout the construction process.
The Pennsylvania Turnpike works closely with the responsible county conservation districts and other stakeholders throughout the duration of the construction project until a stable condition is achieved and E&S BMPs can be removed. Example E&S BMPs used on Turnpike construction projects can be found in the PHOTOS section. Additional details on PADEP and EPA’s NPDES programs can be found in the LINKS section.
Post-Construction Stormwater Management
The way that the Pennsylvania Turnpike and other public entities manage stormwater is critical to reduce the risk of increased runoff. In developed or urbanized areas, more water arrives into a stream more quickly, due to more impervious surfaces.
In wooded areas, rainfall is absorbed by native soils (a process called infiltration), stored as groundwater and slowly discharged through springs into streams and other water bodies. Increased runoff is less significant in wooded areas because precipitation is absorbed into the ground and vegetation, reducing the amount of runoff into a stream.
As watersheds become more urbanized, much of the vegetation is replaced by impervious surfaces, such as pavement, reducing the area where infiltration can occur. The NPDES program requires a Post-Construction Stormwater Management (PCSM) plan to demonstrate how increased stormwater runoff from impervious surfaces will be managed to mimic or reduce the pre-construction conditions. Permanent BMPs, such as stormwater basins can be used to not only to capture and control the stormwater, but also allow water to infiltrate into the ground. Infiltration removes pollutants, such as sediment, from the stormwater before leaving the watershed, simulating the natural environment.
A stormwater inlet is a common site on the Pennsylvania Turnpike and most other highways and roads. Stormflows are collected by these inlets, and the water is delivered through pipes to control roadway runoff and reduce roadway flooding.
Drainage pipes and ditches or swales carry runoff to stormwater basins that are built along the Turnpike to retain or reduce runoff and collect sediment and other pollutants Some basins are also constructed to infiltrate stormwater back into the groundwater while others slowly release stormwater overtime.
The next time you’re traveling on the Pennsylvania Turnpike, remember the important job these facilities — storm inlets, ditches and basins — perform to reduce runoff and keep waterways clean for all plants and animals who rely on fresh water.
Municipal Separate Storm Sewer Systems
MS4 is an acronym for “Municipal Separate Storm Sewer System.” An MS4 is usually owned and operated by a municipality or other entities like the Pennsylvania Turnpike Commission. It is made up of storm inlets, pipes, ditches, swales and stormwater basins used to collect and transport stormwater runoff which could be discharged into streams and rivers or infiltrated into the groundwater.
An MS4 is “separate” from a combined sewer system which collects rainwater, sewage and wastewater in the same pipe and carries it to a treatment plant before it’s discharged. MS4s use stormwater control measures, such as basins, to manage the flow of water and reduce pollutants such as sediment.
To prevent pollutants from being discharged into streams and rivers, the Environmental Protection Agency (EPA) and Pennsylvania Department of Environmental Protection (PADEP) required that municipalities and other entities such as the Pennsylvania Turnpike Commission develop a stormwater management program to reduce pollutants from being discharged to Waters of the Commonwealth.
To learn more about Municipal Separate Storm Sewer Systems, please visit this DEP FAQ.
What Does the Pennsylvania Turnpike Do?
For decades, we at the Pennsylvania Turnpike have taken numerous steps to better control stormwater runoff as well as to limit impurities in runoff across our system. In the coming months, we will launch an even larger Clean Water initiative aimed at improved protection of the streams and rivers that pass beneath or near our 552-mile highway system.
What Can I Do?
The Pennsylvania Department of Environmental Protection (DEP) has a mission to protect Pennsylvania’s land, air and water from pollution and provide a cleaner environment for the health and safety of its citizens. The DEP’s Bureau of Clean Water works with the Pennsylvania Turnpike and other entities to help ensure we follow regulations to reduce stormwater runoff as well as the pollutants in that runoff. Urban runoff pollution is a problem that has no boundaries, and neither does the solution! Residents can also do their part to reduce stormwater runoff. Click here to learn how.
Contact Us with questions or concerns.
