Etna Borough is a COMBINED SEWER COMMUNITY (CSO), which means our stormwater is mixed with our sanitary sewage in our sewer piping system.  During rain events, this can cause a surcharging of our sewer system which in turn can activate PERMITTED overflows into our creek and river.  During these rain events, our catch basins can be inundated with debris, including cigarette butts, trash, oil and other debris which take up capacity in the system resulting in overflow to our streams, affecting the water quality.  In order to keep our combined system clean, Etna annually hires a contractor to flush out the lines of this debris.  This is a costly expense, but once debris is in the sewer system it is difficult to remove without the aid of a sewer vactor truck. 

Since 2014, the Borough has been installing “filter basins” at high flow areas in our community.  These filter basins are designed to capture and retain storm water pollutants including: sediment, trash, vegetation, nutrients, coliform bacteria, oil/grease and dissolved materials.  The filters basins have cartridges within them that capture these materials.  Our Public Works Department is then able to remove the cartridges and the debris materials which have been trapped, preventing from entering the system and overflowing into our streams.  These have been installed at 18 locations so far, with several more coming this year.  After removing the debris, our Public Works Department weighs the materials so that we can track what we are removing from the system and from overflows.  In one six month period, fifteen of these basins had a total weight of 1,374 pounds of sediment removal.  While the cost of a cartridge is roughly $100.00, the cost of hiring an outside vendor far exceeds that cost, and that work happens after large rain events.  These filter basins aid in easing the impact that large rain events have on sewer system capacity as well as reduce sediment overflow into our precious stream and river. 

In the Borough’s efforts to address combined sewer overflows and storm water run-off problems, the Borough adopted Ordinance No. 1341, the Residential Downspout Disconnect Ordinance. This ordinance encourages and requires a permit for downspout (roof drains/gutters) disconnection from the combined sanitary and storm water system in Etna. By removing roof drains where appropriate through approved methods you can help yourself, your neighbors and the environment. Etna is a permitted, combined sewer community which means the storm water and sanitary sewage are collected and carried in one system of piping. During heavy rain events, the capacity of the sewer system to carry away sewage can be exceeded. When that occurs, it is called surcharging and overflows occur into the creeks and streams. This same thing can occur in your basement when your roof runoff enters the same pipe that removes your sanitary sewage. During an intense rainfall, your connecting pipe can be overloaded, causing a backup into your basement through the floor drain. Removing the storm water connection to your service lateral can remedy basement flooding problems in many cases.

When storm water makes its way to the sewage treatment plant (Allegheny County Sanitary Authority ALCOSAN), it is treated like sewage, which increases the cost of sewage for all of us. Correctly removing roof drains from the sewer system by approved and permitted methods can potentially reduce the amount of rainwater that enters the sewer system.