Once Rain hits the ground/water bodies, it is no longer Rain, it isRising Flood Waters. 

And Jay Hinrichs the main reason I would see in scoping a new sewer line like that is it is very common to get what they call a belly in a sewer line which is where the ground underneath sinks in one area causing essentially a low spot and can be very common due the so much change in the ground on a new construction and only wound take one rain or some ground water.

I can’t wait until that stuff seeps into the groundwater.  

For commercial properties, former dry cleaners can be very problematic. has property always been connected to public sewer or did it use septic system that can discharge pollutants into groundwater. 

The environmental company stated that there were nosoil vapor issues present on the subject property but there werelow levels of contamination in the ground water.

If you are in coal country this makes the possibility a bit higher , sometimes a new shaft will change the ground water flow effecting a well .A friend of mine is in Confluence Pa , his well is 1300 feet deep , and it produces 2 gallons per minute , he has 4 Large pressure tanks to have reserve water .

Also their population has grown by almost 50% since 2000http://www.city-data.com/city/Bakersfield-Californ...I know that some areas in the central valley have experienced literal sinking due to pulling too much groundwater out of the ground though.

I know in Florida landfill space is limited due to high ground water which makes disposal costs expensive.

Is it ground water , rain water , is it a pin hole in the water main ?  

All of the south metro area is using groundwater.