How the Milford Aquifer flows from the sources

By JOE ZENES AND GAIL LAMB-DOTO
Posted 9/20/22

MILFORD, PA — We had an opportunity to observe the surface waters related to a 44-acre commercial parcel during a recent rain event on September 5 through 7. We unofficially had four inches of rain in two gauges, but locally there were heavier amounts over the area.

This item is available in full to subscribers.

Please log in to continue

Log in

How the Milford Aquifer flows from the sources

Posted

MILFORD, PA — We had an opportunity to observe the surface waters related to a 44-acre commercial parcel during a recent rain event on September 5 through 7. We unofficially had four inches of rain in two gauges, but locally there were heavier amounts over the area.

[The parcel lies by the I-84/Route 6 interchange. It is the subject of concern over a proposed warehouse project, and contains the upper springs of the Milford aquifer.]

This was an excellent example of how important the wetlands are to the aquifer and springs. Surface water remained clear, flowing onto the property, and the discharge stream volumes increased greatly without any sediment load below the downslope wetlands of the proposed mega-warehouse site. 

Stormwater runoff observed during three events since July 24 was mainly from highway and road surfaces, running into wetlands on adjacent properties across the highway, or to the east of the existing business’ driveway. 

The 44-acre parcel’s surface water drains directly to the Sawkill Creek, where it is perched above the Milford Springs. (See graphic left.)  

The geographic area encompassed by the conceptual groundwater flow model for the Milford Springs consists of adjacent watersheds of the Sawkill Creek and Vantine Brook. Surface waters and groundwater originate from their sources in the headwater areas and flow downstream to the Milford Springs. 

The conceptual flow model is part of the Milford Water Authority’s Source Water Protection Plan from 2006. 

The glacial outwash aquifer (unconfined aquifer) receives some recharge directly from surface water infiltration. Previous chemical tracer studies documented that the Sawkill Creek loses water through streambed infiltration in the vicinity of the Milford Springs. 

When water in the stream channel and streambed is at a higher elevation than the underlying water table surface, the stream is said to be “perched.” Sawkill Creek and Vantine Brook are both perched streams. The Sawkill is perched for several hundred feet of its course just south of I-84 before it flows over Pinchot Falls. 

Stream water infiltration from the two watersheds provides significant additional recharge to the outwash aquifer, and thereby sustains a higher flow of the springs during droughts. The previous tracer studies demonstrated that some water from Sawkill Creek seeped through the streambed and from the commercial property containing the Upper Springs. The surface water from the subject property eventually discharges into the Sawkill Creek in the vicinity where it is perched above the Milford Springs. The tracers flowed toward and discharged from the springs. 

The four sources of the water that comprise the discharge of the Milford Springs are 1) rainfall and snowmelt that directly infiltrate into the outwash aquifer. 2) Upland tributary stream water that infiltrates into the outwash aquifer before reaching the Sawkill Creek’s stream channel. 3) Groundwater in the underlying bedrock aquifers that discharges under artesian pressure up into the outwash aquifer. 4) Stream water in the channels that seeps into the outwash aquifer. The springs are vulnerable from surface water flowing in the vicinity of the Milford Springs.

The studies found the surface waters (streams) were a measurable component of the total flow of water from the springs. The rates of flow of water in stream channels are commonly more than 1,000 times faster than the rates of flow of groundwater in underlying aquifers. Deep groundwater flow was the prominent source of water discharging from the springs.

[For more coverage of the springs and potential development, visit riverreporter.com/stories/public-weighs-in-on-potential-mega-warehouse,58131 and other stories.]

Joe Zenes and Gail Lamb-Doto live in Pike County, PA. 

milford, lvl, aquifer, milford springs, sawkill creek, environmental protection

Comments

No comments on this item Please log in to comment by clicking here