PA Environment Digest Blog: Penn State Extension Watersheds: How Land Use Impacts Groundwater

By Peter Wulfhorst, AICP

Groundwater is an essential water source for many users in Pennsylvania, especially in rural areas of the state. More than one million private wells exist, and about 20,000 new wells are drilled annually in Pennsylvania.

Human activity and how we develop our land are large factors in the contamination of our groundwater.

Agricultural activities can contaminate our groundwater due to the over application of pesticides, herbicides, and fertilizers. These fertilizers can contribute nitrogen to our groundwater, which has a health contaminant level of 10 mg/l.

Suburban sprawl development threatens our groundwater quality by contributing runoff from roads and parking lots which carry pollutants like oils and greases, nutrients from fertilizers, salts from winter road treatments, nutrients like nitrates from failing on-lot septic systems, and illegal roadside dumps. Industrial activity contributes volatile organics, petroleum products, and organic pollutants such as PCBs.

Mining and gas drilling can impact groundwater quality by increasing levels of salt (sodium and chloride), metals (iron, manganese, barium, strontium, arsenic, lead, and other trace metals), and various organic materials (oil, grease, surfactants, benzene, etc.).

Increased land development also reduces the supply of our groundwater. As impervious surfaces that characterize development -- roads, parking lots, driveways, and roofs -- replace meadows and forests, rain can no longer seep into the ground to replenish our aquifers. Instead, it is swept away by gutters and sewer systems.

The sprawling of America has translated into a significant loss of valuable natural resources.

Undeveloped land is valuable not just for recreation and wildlife, but also because of its natural filtering function. Wetlands, for example, act like sponges, absorbing precipitation and runoff and slowly releasing it into the ground.

To ensure that your drinking water is healthy, have your water tested every year. Many tests can be done on your water; however, having all of them done is usually not necessary and can be expensive.

It is a good idea to have your water tested annually for Coliform bacteria and every three years for pH and total dissolved solids.

However, if you can determine what potential contaminants are threats to your water supply, you can more carefully select the type of tests and analysis that you will need to be done to ensure the safety of your water.

Have your water tested by a Pennsylvania Department of Environmental Protection (PADEP) certified drinking water laboratory. The PA DEP certifies water testing laboratories to ensure they are using analytical procedures designed to provide accurate test results.

You can obtain a list of PA DEP certified labs online.

(Reprinted from Penn State Extension Watershed Winds newsletter. Click Here to sign up for your own copy (bottom of page).)

Upcoming Events:

-- April 26: Water Webinar Series: Hard Water Causes & Treatments

-- April 28: Uses And Benefits Of Rain Barrels

-- May 20: Water Webinar Series: Household Water System Maintenance

-- May 24: Water Webinar Series: Ask The Drinking Water Experts Panel

-- Private Water Supply Education & Testing - Multiple Dates, Times

-- Online Water Courses

-- Volunteer Riparian Buffer Planting Events

-- Master Watershed Steward Jim Walter Inspires Environmental Action

-- Celebrate May 18 PA Native Species Day With Master Watershed Stewards