Times Columns

2020 Water Quality Report


Pennsylvania Department of Environmental Protection

Water Quality Report for 2020

Every two years Pennsylvania’s Department of Environmental Protection (DEP) produces a report on the quality of water in our streams and lakes. This is known as the Integrated Water Quality Report, and you can find it on DEP’s website at These reports are fascinating, but best appreciated on desktop, laptop or large tablet or computer screen.

For example, there is a map of “Streams Prioritized for Restoration” by DEP.  Searching on this map for “Adams County, PA” shows that DEP has prioritized restoring the headwaters of Conewago Creek, including Opossum Creek and its headwaters. The prioritization area ends where Opossum Creek flows into the Conewago.

The graphics on this web site are beautiful, but there are also valuable data available behind the scenes. You can download DEP’s data to do your own graphs or maps depending on your interest.

Any website this powerful is likely to be a little daunting to use at first, or even at second or third if you are as slow as I am. The material is presented in two parts – the Integrated Report and a mapping application – and video tutorials for each part. I recommend spending a few minutes watching the tutorials, even if you’re averse to watching web videos—I managed to waste a lot of time getting confused before I finally went back and watched them.

Another piece of background information is that PA Code 93.3 lists “Protected water uses,” defining the categories for development of water quality criteria. There are five main categories: Aquatic Life, Water Supply, Recreation & Fish Consumption, Special Protection, and Other (or Navigation). An “attaining” waterway or stream segment meets the four standards for the four purposes. If a stream segment is not attaining any one of its four uses, it is considered “impaired.”

In the report, Category 1 waters meet all three categories. For instance, in Adams county, a large part of the East Branch Antietam Creek in Michaux Forest falls into Category 1, but nothing else.

A more positive view is provided by a map of “Category 2 Waters”, which are those that meet the criteria for some of the uses, but not all. This seems to apply to most of the waters in Adams County, so all is not lost!

Another thing I found interesting with respect to Adams County was the map of assessments that changed between the 2018 report and the 2020 report.  Sadly, very little changed. On the positive side, four small tributaries to Little Marsh Creek did upgrade from “Impaired” to “Attaining” for Aquatic Life.

The only other change was to Stevens Run, which goes right through Gettysburg Borough. Stevens Run was “Impaired” and is still “Impaired”, for Aquatic Life, but the causes changed. The new causes are listed as “Flow Regime Modification, Nutrients, Siltation.” Sigh.

If you spend enough time with these data you will discover that much more widespread monitoring is needed. We in the Watershed Alliance of Adams County are working to help address this need. WAAC volunteers perform monthly tests on several waterways to determine trends in such factors as nitrates, phosphates and sedimentation to help determine where improvement can be made.

If you would like to help out, we’d love to hear from you! You can reach us at