You may question their sanity, but the FTTU testing crew was out with temperatures in the teens at Rock Run taking water samples this past Saturday.
It was a “crisp” but beautiful winter day at Linn Run State Park, Rock Run was flowing moderate and as always, clear.
Air Temp: 19 degrees F
Water Temp: 29.5 degrees F
Linn Run Gauge: 1.91 ft.
Linn Run Discharge: 21.8 ft³/sec.
We also collected some snow from around the area, allowed it to melt, and took readings of those samples as well.
A new year of water quality testing begins on Rock Run. The flow is high with rain and snow runoff, so the stream’s alkalinity content is put to the test.
Air Temperature: 39 degrees F
Water Temperature: 40.5 degrees F
Linn Run discharge: 22.0
Linn Run gauge: 2.88
The testers braved the chill and completed the final water tests at the mouth of Rock Run on December 5.
Air Temperature: 36 Degrees F
Water Temperature: 40 Degrees F
Linn Run Gauge: 2.35
Linn Run Discharge:22
Highs and Lows
Air Temperature: High – 72 in August. Low – 27 in January.
Water Temperature: High – 67 in August. Low – 37.5 in January
pH: High – 7.5 in November. Low – 6.5 in January.
Alkalinity: High – 11.4 in August. Low – 2.2 in May.
Linn Run Gauge: High – 2.38 in January. Low – 1.4 in October.
Linn Run Discharge: High – 48.8 in March. Low – too low for a reading in August.
Averages for 2020
Air Temperature: 51.8
Water Temperature: 50.5
Linn Run Gauge: 1.92
Linn Run Discharge: 17.92
Surprisingly, despite the drought, Linn Run gauge and discharge averages were higher in 2020 than 2019 probably because of high flows early in the year.
pH was up in 2020, but alkalinity was down slightly probably because high flows produced low readings in January, February, March and May.
You can view the whole 2020 report by clicking here Rock Run Tests 2020.
The Citizen Scientists were at it again on Saturday, November 1st.
Readings taken at the mouth of Rock Run are as follows:
Air Temperature: 48 Degrees F
Water Temperature: 47.5 Degrees F
Linn Run Gauge: 2.01
Linn Run Discharge: 9.0
We also hiked in to the headwaters on the East Branch and took readings there.
MAIN STEM 200′ Below Confluence
The effects of the limestone sand dosing are plain to see from the difference in alkalinity. The limestone sand piles are located near the top of the East Branch. The West Branch has not been treated with limestone. The alkalinity test at the mouth shows the influence of the limestone (+7.4) 1.5 miles downstream.
The East Branch is about 3/4 mile long. The readings were taken about 1/2 mile from the limestone. Limestone sand is evident throughout the entire length of the East Branch. The West Branch is smaller and has a lower flow.
Here’s the readings taken at the mouth of Rock Run on October 4, 2020.
Air Temperature – 39 Degrees F
Water Temperature – 50 Degrees F
Alkalinity – 9
pH – 7.2
Linn Run Gauge – 1.4
Linn Run Discharge – 1.8
Samples were taken upstream above the limestone sand piles.
pH – 4.8
Alkalinity – Zero!
Water Temperature – 50 Degrees F
Much needed rain has brought up the flow and a breath of fresh “air” for the trout.
Air Temperature: 68 degrees F
Water Temperature: 65 degrees F
Linn Run Discharge: 2.5
Linn Run Gauge: 2.04
The Linn Run gauge remained around 1.4, well below average, for most of the month of August until the rain of August 28th brought levels above 2.0.
Some rain would be nice.
The gauge reading on Linn Run was the lowest recorded since we started taking these reading in October 2017. The alklinity test was the highest of 2020.
The discharge for Linn Run, measured in cubic feet per second, was unavailable on the USGS website because, it appears, the flow was below the minimum measurement of 2.0. The median flow for this time of year is 2.5 cubic ft/sec.
In the photo at left, Rock Run appears to be dried up, but there is indeed a flow in at least two of three channels.
Air Temperature: 72 degrees F
Water Temperature: 67 degrees F
Linn Run Gauge: 1.36
Flow goes down, alkalinity goes up, here’s the results of water testing for July.
Air Temperature: 70 Degrees F
Water Temperature: 63 Degrees F
Linn Run Gauge: 1.42
Linn Run Discharge: 5.9
Turbidity: Low & Clear
Lowest flow of 2020. Rain Please!
On Saturday, May 30, FTTU volunteers Denny Hess, Monty Murty, Ron Miller and Scott Minster conducted a detailed water quality survey on the lower section of Rock Run, a Linn Run tributary in the state park.
In addition to our normal pH and alkalinity readings, dissolved oxygen and total dissolved solids tests were also done. We also conducted a macroinvertebrate study with leaf packs that had been soaking in the stream since December 2019.
Leaf packs are an alternative method of collecting stream dwelling organisms which is usually done with a kick net. With leaf packs, leaves from the banks of the stream are placed in mesh bags which are then anchored to the stream bed. In time, organisms take up residence among the leaves in the bag. The bags are retrieved, cut open and the contents inspected for macroinvertebrates. The macros are sorted by scientific order, counted and the results are compiled into an EPT Index.
The EPT Index stands for: Ephemeroptera (mayflies); Plecoptera (stoneflies) and Trichoptera (caddis flies). An abundance of these orders of insects is an excellent indicator of good water quality since they are pollution intolerant.
Within the Rock Run leaf packs, we found stoneflies, mayflies, hellgrammites, crayfish, cranefly larva and both cased and net spinning caddis flies. The results are scored on the basis of how pollution tolerant the samples are. An EPT score of 20 or less is ranked as “Poor”; 20-40 as “Fair”; and above 40 as “Good”. Rock Run scored 41.2, just enough to gain a “Good” designation.
Stoneflies are by far the most abundant macroinvertebrate inhabiting Rock Run, with the prehistoric looking roachlike variety making up the majority of the stoneflies. According to McCafferty’s book Aquatic Entomology, “(roachlike stonefly) Larvae are herbivoredetritivores (feeds on dead organic plant matter) and occur primarily in springs and streams of mountains, commonly in leaf packs.” There were also a lot of small thin stoneflies found possibly a variety known as Slender Winter Stoneflies. The next most abundant organism were sowbugs.
Here’s the numbers on the water tests:
Air Temperature: 59 degrees F
Water Temperature: 57.5 degrees F
Linn Run Gauge Height: 1.75
Linn Run Discharge: 9.33
Total dissolved solids was low (good)
Dissolved oxygen was high (also good)
All looks good on Rock Run except we would like to see alkalinity of 10 or more, which we are trying to help by placing limestone sand in the headwaters. Also a little better diversity in the macros would give us a better EPT score. We suspect a kick net survey may turn up more mayflies and caddis since rocks and gravel are the type of habitat they prefer.
The charts for Rock Run water tests for 2020 can be viewed here Rock Run 2020.
Here’s a link to a video shot by member Ron Miller of FTTU Vice President Denny Hess conducting monthly water sampling on Rock Run.
5/01/2020 PH & Alkalinity test, on Rock Run
Water samples are collected at the mouth of Rock Run which has been treated for acidity with limestone sand since 2005. The sampling location at the mouth is furthest from the treatment site which is in the headwaters. The reasoning is, that if pH and alkalinity numbers are good here, then it should only be better further upstream.
• Water samples are collected from the stream in glass jars.
• pH is measured using meters that are calibrated using solutions at home.
• We use three different meters and average the results.
• Alkalinity is measured by titration.
• 100 ml of stream water is added to a beaker.
• A packet of indicator powder is added to the sample and mixed until it dissolves.
• The water sample turns green.
• An acid solution is then dripped into the water sample with a syringe-like instrument.
• The acid solution is added drop by drop by turning a dial on the device.
• The dial has a meter which records how much acid solution is added to the sample.
• Once the sample turns purple, it is then sloshed around in the beaker.
• The sample will turn a grayish green or gray/purple.
• More acid is added until the sample turns purple and stays that way.
• If it goes to bright pink, we’ve gone too far.
• Once the desired color is achieved, the number on the dial is recorded. We usually do the test twice and average the results.
• The more acid solution dripped into the water sample, the higher the number and the higher the number, the more alkaline the sample is.
In this case, the sample almost immediately turns purple, then goes gray when stirred, then back to purple when more acid is added. The meter reading was 2.2 which indicates low alkalinity. We generally get low alkalinity when the flow is up, and higher readings when the flow is low. We think this is due to the stream working hard to buffer out acidity from rain and run off in high flow conditions. Our pH readings are consistently good ranging from low to high 6 readings. A pH of 7 is ideal and we would like to see alkalinity of 10 or more, but readings of zero have been taken before the project began.
Ron’s video also shows some wild brook trout caught in Linn Run, some with gill lice. Gill lice is not fatal to adult trout but can reduce trout numbers when combined with other stressors. This is why the PA Fish and Boat Commission has switched the Trout in the Classroom program to rainbow trout to eliminate the chances of introducing gill lice to a stream.