The mission of Stream Watch is to increase citizen community engagement in water resource protection and improve our knowledge of stream conditions based on measured stream data. Year-round volunteers assist in collecting data, and we offer seasonal internships to students looking to gain field experience through our partnerships with Stroud Water Research Center, Delaware Nature Society, and University of Delaware Water Research Center. Volunteers collect grab samples for lab analysis, conduct visual and in-stream water quality and habitat analyses, and help to manage the growing stream sensor network. Please contact Shane Morgan directly at mpc@whiteclay.org if you are interested in volunteering for this program and learn more about our volunteers here.
Watch this video to learn more about what University of Delaware interns are doing to assist with water quality monitoring in the Whtie Clay.
FECAL INDICATOR BACTERIA
People frequently ask if it is safe to swim in White Clay Creek. The answer is complicated. Bacterial samples are collected at multiple sites 5-10 times during the recreational season during base flow (48 hours or more of less than .25” of rain preceding the sample grab). This is the time of year when most people use the creek and are likely to be in direct contact with the water. There are 30+ monitoring sites throughout the watershed (DE/PA) where the White Clay Wild and Scenic Program takes samples. This provides a snapshot of the water quality during the recreational season and results often show that the creek does not meet state or federal standards set by the Clean Water Act. However, that does not mean people should not get out and enjoy the creek. They must take the proper precautions, like staying out of the creek during a rain event (up to 72 hours after). Rain washes fecal material from pets, wildlife, agriculture, and failing septic systems into the Creek, elevating the levels of harmful bacteria or fecal indicator bacteria (FIB).
Fecal indicator bacteria (FIB) tend to attach themselves to soil particles, so high suspended solids after a rain event lead to increased harmful pathogens. Below are graphs displaying the geometric means of recreational season bacteria levels at 30 sites throughout the watershed 2013-2020 taken at base flow. It should be noted that Delaware and Pennsylvania use different standards to measure bacteria that are harmful to human health. The state of Delaware uses Enterococcus, while the state of Pennsylvania uses Escherichia coli (E. coli). We tested Enterococcus in the entire watershed (PA/DE) to make comparisons, but we only tested E. coli in Pennsylvania. The graphs below show the geometric mean for each site during each 30-day sampling period during the recreational season when most people are in the water. The red lines represent the state standards for each bacteria. It should be noted that the larger tributaries like the main stem and main branches generally have lower bacteria counts due to dilution then smaller headwater streams. While levels are generally above the state water quality standards, swimmers and waders can take the following precautions to recreate to protect themselves from harmful bacteria:
Avoid getting in the water during heavy rainfall and for approximately three days afterward.
Avoid getting in the water if you are sick or have open cuts, scrapes, or wounds.
Shower with soap and warm water after swimming.
Look for signs of poor water quality, such as dead fish, trash, and oil slicks or scum on or near the water, and do not enter water if you see any of the above.
Bring hand sanitizer or soap and clean water for washing your hands after enjoying the creek.
year-round monitoring
A few sites have stream sensors installed to collect continuous in-stream temperature measurements. At these sites, water samples are also collected monthly year-round and analyzed for nitrate (NO3N), orthophosphate (OP), and chlorides (CL). Hand-held water temperature and conductivity measurements are also recorded at each site visit. Additionally, USGS is doing an intensive study on White Clay Creek using next-generation water observation systems (NGWOS) at several locations in the watershed. The study began in 2019 and includes new or enhanced streamflow stations, self-supplied domestic well monitoring, paired air/water temperature study, sediment study, and chloride sampling. The USGS White Clay Creek subbasin intensive data can be found online using the USGS Map Viewer.
chlorides
The year-round stations improve our understanding of the issue of salt pollution in streams and rivers (see Freshwater Sources Less “Fresh” from Greater Salt Use, Scientists Say). Salt and brine spread on roads during winter coats roads and parking lots throughout the region. During thaws and rain events, this salt is carried into streams where it can have chronic and sometimes acute effects on biological communities. According to the U.S. Environmental Protection Agency (USEPA), freshwater aquatic organisms should not be affected unacceptably if:
1. Chronic exposure—Four-day average concentration of dissolved chloride, when associated with sodium, does not exceed 230 mg/L more than once every three years.
2. Acute exposure—One-hour average concentration does not exceed 860 mg/L more than once every three years on average.
During snow melts preliminary data from our sensors and grab samples show Conductivity levels in the thousands for prolonged periods. Conductivity is a measure of the ability of water to conduct an electrical current and is directly related to the amount of material (ions) dissolved in the water, meaning that conductivity rises as salt enters the water. Wintertime increases in conductivity in streams throughout the Delaware River Basin have been recorded by the sensor stations and, as expected, have been most pronounced in urban areas with prevalent paved surfaces that are treated with road salt. Below is an example of what we are seeing at Mill Creek during periods of snowmelt.
nutrients
The majority of stream miles in the White Clay are listed as impaired for nutrients (nitrates and phosphates) which can enhance algal blooms, deplete oxygen available in the water, and create more expensive treatment costs to water purveyors who depend on the White Clay for drinking water. We are working with our partners to support agricultural and stormwater best management practices (BMPs) on agricultural, municipal, and residential properties throughout the watershed to prevent nutrient and sediment pollution. Agricultural and stormwater BMPs, like manure management, cattle fencing, stream-side tree plantings, vegetated swales, and rain gardens help collect stormwater at the source, slow it down, and allow it to infiltrate and be filtered by plants and soil before it enters the waterway.
Stream Biology
Fecal bacteria are a potential issue in White Clay streams. To understand the extent of this contaminant the Wild and Scenic Program conducts stream monitoring at several locations during the recreational swim period (June-September). Monitoring began in 2012 in partnership with the Pennsylvania DEP and continues today in partnership with Stroud Water Research Center, Delaware Nature Society, and University of Delaware. The data collected indicates high levels of fecal bacteria and correlates with preliminary results from USGS sampling in the White Clay Creek Preserve. Sixty seven stream miles were added to the Pennsylvania Department of Environmental Protection list of impaired streams for exceeding water quality standards for bacteria. Land use maps were created for the areas draining to each of our sampling sites to help determine potential sources of contamination. Starting in 2016, we began conducting additional testing using genetic markers to determine the presence or absence of suspected bacterial sources. Determining which bacterial sources are present in the water can lead to more cost effective restoration efforts targeted at those areas that will be most beneficial in terms of reducing pollutants.
Macroinvertebrates (small aquatic organisms) are excellent indicators of water quality. During 1991-2008, The White Clay Watershed Association gathered baseline data on stream health, and in 2004 partnered with Stroud Water Research Center to conduct a more robust macroinvertebrate study of all 19 Stream Watch sites. The results indicated that only one out of nineteen sites was considered good, ten were fair, and the remaining eight were considered poor based on what was found living there.
Click here to download a brochure of the 1991-2008 Stream Watch project.