Water Quality & Monitoring
Because clean water is essential to life, it is important to understand the health of our waterways. Is it safe to drink? What about swimming, kayaking, fishing, or irrigating crops?
Many pollutants in our waterways negatively affect aquatic ecosystems and human health.
Water-quality monitoring can serve many purposes, including gathering baseline data about stream health, identifying pollution “hotspots,” guiding future restoration and management activities, and educating communities about their local streams.
Some parameters of interest include the following:
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High dissolved oxygen - DO for short - is good for the critters in our streams.
Macroinvertebrates like mayflies and stoneflies need high DO levels in the water. DO concentrations in a flowing stream should be above 5.0 mg/L.
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Excess nutrients, particularly nitrogen and phosphorus, can lead to harmful algal blooms which deplete dissolved oxygen and block light in aquatic ecosystems. This process is known as eutrophication.
For nitrate-nitrogen (NO3-N), the drinking water standard is 10 mg/L. Concentrations over 10 mg/L may lead to increased risk of blue baby syndrome in infants.
For aquatic life in streams, nitrogen reference levels range from 0.12 to 2.2 mg/L total N. Environmental reference levels for phosphorus range from 0.01 to 0.075 mg/L total P. Concentrations higher than these ranges may indicate eutrophication and human influence.
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Sediment (think soil running off a field or construction site) can smother bottom-dwelling critters. Nutrients and other compounds can bind to sediment and be transported through a stream.
Turbidity measures how cloudy water is. High turbidity levels are associated with higher levels of disease-causing organisms like viruses, parasites, and bacteria.
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Most aquatic organisms require a specific temperature range. Native brook trout prefer streams that do not get warmer than 65 °F (about 18 °C).
Cold water also holds more dissolved oxygen than warm water.
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Standard range: 6.0 to 9.0 pH units.
Mining activities can result in streams suffering from acid mine drainage, which results in low pH. A pH outside the range above is harmful to most freshwater species.
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Some metals, like lead, pose health threats when present in drinking water in high concentrations. The Environmental Protection Agency's drinking water regulations establish maximum allowable concentrations for these chemicals in drinking water.
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Bacteria such as Escherichia coli pose health risks and come from human and animal waste.
The maximum contaminant level goal (a non-enforceable public health goal) for E. coli in drinking water is 0 mg/L.
For more information about water quality standards, see Pennsylvania’s Code 25, Chapter 93 water quality standards and EPA’s National Primary Drinking Water Regulations.
Agencies like the United States Geological Survey (USGS) and Susquehanna River Basin Commission (SRBC) have continuous in-stream monitoring stations in and near Lebanon County. These streamgages record measurements every 15 minutes. Some only measure streamflow, while others measure water-quality parameters including temperature, nitrogen, and dissolved oxygen.
In the map below, blue dots indicate gages that only measure discharge. Green dots indicate gages that measure nitrogen. Pink dots indicate gages that measure other water quality parameters, but not nitrogen.
For more information about a specific gage, click on the dot and select “More Info” to go to the agency’s webpage for that station.
Streamgages in Lebanon County
What are the differences between the streamgages?
| USGS Supergage | USGS Water-Quality Gage | USGS Discharge Gage | SRBC Water-Quality Streamgage | |
|---|---|---|---|---|
| Continuous in-stream monitoring | ||||
| Discharge | ||||
| Temperature | ||||
| Specific conductance | ||||
| pH | ||||
| Dissolved oxygen | ||||
| Turbidity | ||||
| Nitrate plus nitrite | ||||
| Gages in or near Lebanon County |
How does a USGS Streamgage Work?
The Importance of USGS Water-Quality Super Gages
Thank you to the Lebanon County Commissioners and NRCS for providing funding toward the Swatara Creek Supergage!
Other Data
In addition to the data collected by USGS and SRBC at the streamgages above, many other entities collect data in Lebanon County.
The Quittapahilla Watershed Association has a Tier 3 volunteer monitoring program that includes six regular sites in the Quittapahilla Watershed. Their data is publicly available here.
The Swatara Watershed Association has a monitoring site at Swatara Watershed Park and has historical data available on their website.
In the Conewago Creek Watershed, the Penn State Agriculture & Environment Center conducts quarterly synoptic sampling at 30 locations, about half of which are in Lebanon County.
The Pennsylvania Department of Environmental Protection (DEP) collects data and publishes it to eMapPA.
To learn how you can get involved in water-quality initiatives in Lebanon County, contact LCCD!