QUALITY ASSURANCE/QUALITY CONTROL
Maryland Department of Natural Resources followed specific procedures to ensure that the Tributary component of the Chesapeake Bay Water Quality Monitoring Program design was properly implemented and managed with sufficient accuracy, precision, and detection limits. Accuracy (closeness to the true value) of collected data was controlled and assured by proper use, calibration and maintenance of both field and laboratory equipment for the measurement of physical and chemical parameters.
The procedures used to control and assure the accuracy of field measurements involved the calibration of field instruments, verification of calibrations, and equipment maintenance. Most of the details of how data acquired with YSI sondes and Hydrolab sondes were quality assured and quality controlled are described in the process description elements in the Lineage portion of this metadata record.
Daily quality control checks which included the running of blanks and standards were used to control and assure laboratory accuracy.
Accuracy of Chesapeake Biological Laboratory, Nutrient Analytical Services Laboratory (CBL NASL) and Maryland Department of Health (MDH) results was also assessed through DNR's participation in the Chesapeake Bay Coordinated Split Sample Program (CSSP) a split sampling program in which five laboratories involved in Chesapeake Bay monitoring analyze the coordinated split samples. CSSP was established in June 1989 to establish a measure of comparability between sampling and analytical operations for water quality monitoring throughout the Chesapeake Bay and its tributaries. The Chesapeake Bay Program Data Integrity Workgroup oversees the CSSP. DNR followed the protocols in the Chesapeake Bay Coordinated Split Sample Program Implementation Guidelines (EPA 1991) and its revisions. Split samples were collected quarterly. Results were analyzed by appropriate statistical methods to determine if results differed significantly among labs. If a difference occurred, discussions began regarding techniques and potential methods changes to resolve discrepancies.
ADDITIONAL COMMENTS
January 2024: There was significant snowfall on Monday and Tuesday prior to sampling ANT0203, ANT0366, CON0180, and POT2386; with snow still reported to be on the ground at these stations during sampling. Similarly, heavy snow fell the Friday and Saturday before sampling the remainder of the Core stations, and snow melt was evident at these stations. The water at BDK0000 was described as being dark orange, however CCR0001 was reported to be less tannic in appearance than usual.
February 2024: A sewage smell was detected at station CB1.0. United States Geological Survey (USGS) was on site at station GUN0258. Very cloudy water was reported at station GWN0115, and hair was seen in the water at ANT0366. Bridge construction and water pumping was in progress at CJB0005 while sampling. It rained Monday night, followed by overnight snow on Tuesday prior to sampling stations LYO0004, NBP0461, NBP0534, NBP0689, SAV0000, YOU1139, POT2766, and TOW0030. Thin and wispy clouds were recorded for stations ANT0203, ANT0366, CON0005, CON0180, POT2386, BDK0000, NBP0023, NBP0103, and POT2766. Hazy conditions were noted at WIL0013 and CCR0001.
March 2024: Noisy geese were on the riverbank upstream from station ANT0203. Rain fell prior to sampling all Core stations this month, with high river water due to the rain recorded for stations CAC0031, MON0155, POT1471, POT1595, and POT1596. Foggy conditions were also reported at those stations, and also at PXT0809, PXT0972, and SEN0008. The water was murky at POT2386 and NBP0326, and described as being ‘high and dirty’ at NBP0103 and LYO0004.
April 2024: It rained earlier in the day prior to sampling stations ANT0203, ANT0366, CON0005, CON0180, CAS0479, YOU0925, LYO0004, SAV0000, and YOU1139; and heavy rain fell all week prior to sampling stations ANA0082, ANT0044, BPC0035, CAC0031, CAC0148, CJB0005, MON0155, MON0269, MON0528, POT1184, POT1471, POT1595, POT1596, POT1830, RCM0111, SEN0008, DER0015, ET5.0, GUN0125, GUN0258, GUN0476, GWN0115, JON0184, NPA0165, PAT0176, PAT0285, PXT0809, and PXT0972, with high flow was reported at those stations. Thin clouds and hazy conditions were noted at stations BDK0000, CCR0001, NBP0023, NBP0103, POT2766, TOW0030, and WIL0013. The area upstream directly above station SAV0000 was reported to be clearcut, with the water at this station being murky.
May 2024: Very foggy conditions were noted at stations CB1.0 and DER0015; while hazy conditions were reported at stations ANT0366, CON0005, POT2386 and YOU1139. Rain was reported earlier in the day before sampling CAS0479, YOU0925, and CCR0001, and rain fell overnight prior to sampling stations LYO0004 and YOU1139. Clouds were thin and wispy at stations BDK0000, TOW0030, and POT2766. The water was described as being tannic at station CCR0001, murky at YOU0925, and dirty at NBP0103. Pollen was visible in the air at TOW0925.
June 2024: USGS was noted as being on-station while sampling PXT0809. An egg mass was seen on rocks at station POT2386, with small fish visible in the water. Severe storms with heavy rainfall occurred the evening before sampling stations CB1.0, DER0015, GUN0258, GUN0476, GWN0115, JON0184, NPA0165, PAT0176, and PAT0285; high flow was reported at most of these stations. Station BDK0000 was sampled five days later and here the water was reported as shallow, with the water collection bucket hitting the bottom during sample collection.
July 2024: Specific conductivity post-calibrated outside of Quality Assurance/Quality Control range for stations ANT0044, BPC0035, CAC0148, MON0269, MON0528, and POT1830, but the recorded values were deemed reasonable and acceptable. Elodea sp. was seen on both sides of the boat ramp at station NBP01013, filamentous algae was evident at BDK0000, algae was seen in the water at POT2766, and the river was reported to have a green tinge at POT1184. Thin and wispy clouds were noted at stations WIL0013, YOU0925, and POT2766. A sprinkle of rain fell for 20 seconds immediately before the sample was taken at NBP0326. The water level at GUN0125 was very low.
August 2024: The instrument employed for sampling stations RCM0111, ANA0082, CJB0005, PXT0809, and PXT0972 failed prior to post-calibration, however all readings appear normal and acceptable. Hazy conditions were noted at stations NBP0023, XGG8251, and NBP0534. It began to rain while collecting the sample at station POT2386, and at station CON0005 plant matter was reported in the water, presumed to be due to a downpour upstream. The water level was low at BDK0000, CAS0479, and CCR0001, with clearer water conditions being noted at BDK0000 and CCR0001.
September 2024: Low water conditions were reported at stations CAC0031, MON0155, SEN0008, GUN0125, GWN0115, JON0184, NPA0165, CCR0001, YOU0925, LYO0925, and YOU1139. Very clear water conditions were noted at NBP0689 and YOU0925. Algae, snails, and submerged aquatic vegetation (SAV) were observed at POT2766; a large bed of hydrilla was reported at the sampling site at POT2386; and Elodea sp. was visible on both sides of the boat ramp at NBP0103.
October 2024: At station CON0005, half of the bridge was blocked with debris, with an additional foamy build-up of algae and submerged aquatic vegetation (SAV). The remnants of Tropical Depression Helene hit the Potomac watershed over the previous weekend, and water levels were reported to be high at MON0155 and SEN0008, and at minor flood stage at POT1184, POT1471, POT1596, POT1830, and POT1595. A swift water rescue was in progress during sampling POT1595, with many watercraft on-site.
November 2024: Clouds were noted to be hazy at stations GEO0009, NBP0326, NBP0461, and SAV0000. The water was reported to be crystal clear at NBP0689. At station CON0005, all but 10ft of the bridge was blocked by debris. The filter pads from station SAV0000 were noted to be dark green in color.
December 2024: The sampling pads at station BDK0000 were noted to be bright orange. Algae was visible growing on the rocks at station BDK0000, and algae covered the bottom in slow-moving areas at station CON0180 with ice along the edges. Notes report rain while the sample was collected at station POT2766. The bridge at station CON0005 had debris and a foamy build-up blocking three-quarters of the bridge. The water at station YOU0925 was noted to be murky, a plume was seen along the shoreline at POT1471, and at WIL0013 a pipe located on the right shoreline downstream was overflowing into the creek.