FOSC Physical and Chemical Data

Map of FOSC Monitoring Sites

FOSC Chem/Bio WQ Monitoring: Summaries
(to see Coliform results, visit the FOSC Coliform Data page)

 

Wheaton Lane
Flow extremely slow; almost like a pond now, with green surface algae covering about half the channel. Leaf litter and silt on substrate, and an organic-looking film layer near left bank.  Chemical/physical measures were seasonally appropriate, except for chlorine, which was much higher than usual at 0.95ppm for total chlorine.  Three or four fish seen, though probably many more hiding beneath surface and substrate leaves. Woodpecker and squirrels heard. Path well-used by walkers and bikers. Air quality was excellent, noise about average at 47dB.

Dennis Avenue
Flow fairly high. Plunge pool deep and covered with sycamore leaf litter. Most chem/phys measures seasonally standard, except chlorine was quite high. Surfactants were lower than usual at 1.7 ppm.  Saw about a dozen fish, heard squirrel and a jay. About 10 people using the park, some joggers and walkers on path. Air quality excellent, noise about 10 dB lower than last reading, when construction crew was busy nearby.

Flora Lane
Flow a moderate plus, clear and about 2C warmer than the main channel. Flow somewhat salty (salinity/TDS/conductivity). Chlorine was high here as well (0.82ppm total chlorine), surfactants remain around 3.3 ppm. About 30 fish – slightly less than late September. No algae on the outfall pipe, which is unusual here. Channel bottom is usual mica, sand mix with light leaf litter. Heard crickets and a chipmunk. Air quality excellent, noise at 52.8 dB.

Dallas Avenue
Flow moderate, clear. Moderate leaf litter, with sand and cobble channel bottom. Pool now about 18″ deep. All chem/phys readings per seasonal standard, surfactants better than last reading – down to 3.4 ppm. Crickets and blue jays heard. Air quality readings excellent, noise about 3 dB quieter than last time out.

Bennington Drive
Flow moderate plus and clear. Temperature about 2C warmer than main channel. Salinity/ TDS/ Conductivity readings the highest of all our sites this time (TDS at 854 ppm, conductivity at 1221 microsiemens), and surfactants were high as well at 5.1 ppm (slightly better than last session). Chlorine also read very hot at 0.99ppm for total chlorine. About 30 snails around outfall (a big rebound from prior reading). Small willow oak (?) leaf dams on the apron, light brown silt beyond, ending in a clear, full receiving pool. Air quality was excellent, but area was a bit noisier than usual at 57.3 dB.

Wayne Avenue
Flow was moderate, main channel still quite shallow, filled with sand and light leaf litter. Distinct sewage and fainter chlorine smell from outfall (confirmed by subsequent coliform results). Thick orange and some brown algae on outfall pipe. Chem/phys indicators here about the same as Flora Lane, but surfactants higher at 4.2 ppm. Chlorine was hot at 1.04ppm for TC. About 20 fish, school starting to thin out as winter approaches. Yellow jackets still active at tree base nest, saw blue jays. Lots of bikers and walkers. AQ was excellent, noise about standard here at 55.3 dB.

Fleetwood Terrace
Volume was low to moderate, water clear and cold. Very little rock algae. pH a bit high at 8.38. Surfactants were high again at 5.9 ppm. Salinity, TDS and conductivity levels were moderate, chlorine was high (0.96ppm total chlorine), and ammonia-N bumped up a bit to 0.15 mg/L. No fish seen, other than 5 or 6 upstream in the large pool above the riffles. Two minor log dams at the head of the riffles which will go with the next big storm. The slough water levels were quite low, but stream was still running. AQ was very good, not great (17.2ppm PM2.5, 27.4ppm PM10), noise at 51.9 dB.

This is a brief summary of results of chemical and bacterial monitoring at various locations along Sligo Creek.

Wheaton Lane

Flow extremely slow; almost like a pond, covering half the channel and shallow. Light algae/sediment layer on substrate. An organic-looking layer of film and bubbles on left bank. Nothing chemically or physically out of the ordinary here except surfactant were a bit high at 2.7 ppm. About two dozen blacknose dace, 4 or 5 adult water striders, 1 crayfish about 2.5″ long hiding beneath a sycamore leaf. Lots of crickets, and path heavily used by joggers, walker and bikers. Air quality was excellent, noise a bit high at 51.1 dB.

Dennis Avenue

Flow low, extremely clear. Plunge pool deeper now. Bottom only cobble or sand, water quite clear. No leaf litter yet. Most measures pretty standard, except chlorine, which was .28ppm total/.26ppm free. About a dozen small blacknose, dozens of baby waterstriders. Construction nearby added to noise level (59 dB). Air quality excellent, no people using the park, some joggers and walkers on path.

Dallas Avenue

Flow moderate, clear. Some 1/2″ algae and silt on channel bottom. Center channel and upstream plunge pool deeper than previously. All chem/physical readings per seasonal standard except surfactants, quite high at 5.4 ppm. Water about 0.4 pH more basic here than Wheaton and Dennis. Crickets common, cardinal, pileated heard, tree canopy still green. Air quality readings slightly higher than upstream, but still excellent. Noise at 52.7 dB.

Flora Lane

Flow back up to moderate plus, clear water. As usual here, flow is a bit saltier than would be expected of treed tributary, but Georgia Avenue and neighborhood feed this stream. Chlorine low, surfactants moderate at 3.1 ppm. Tremendous school of fish – most we’ve seen here – along whole monitoring reach; perhaps 50 in total. One at least 5 or 6 inches long. Channel bottom is mica, sand, light leaf litter in center, with clay at edges. Air quality outstanding, noise at 53.5 dB.

Bennington Drive

Flow moderate and clear – no suds or odors this time. pH low at 7.42, temperature about 3C warmer than main channel at 19C. Salinity/TDS/Conductivity higher than most, which is the norm here. Surfactants quite high at 5.8 ppm. Ammonia-N extremely low. About 10 snails around outfall (less than prior month), robins and crows heard. Air quality outstanding, noise at 53 dB.

Wayne Avenue

Flow moderate plus, main channel quite shallow now – old 4ft deep plunge pool is perhaps 1 foot deep. Slight detergent smell from outfall. Physical indicators here about the same as Bennington, with surfactants also high at 4.4 ppm. About 60 fish, 80% BnD, 20% white suckers. Mostly fry, few adults. Lots of sand in channel, no algae visible on rocks. SW valve flipped on outfall, likely due to recent storms. AQ outstanding, noise at 55.1 dB.

Fleetwood Terrace

Volume was low, water clear. New cobble, no rock algae – rare for this site (scoured clean by recent storms?). No fish seen – also unusual at this site at this time. The slough water levels were low but steady. Surfactants were quite high at 6.8 ppm. Salinity, TDS and conductivity levels were moderate, chlorine was in line with seasonal readings here, and ammonia-N was fairly low at .09 mg/L. AQ outstanding, noise at 49.8 dB.

August 2020

Bennington Drive
Volume was moderate and clear. A tan algae and silt combination on the apron, with receiving pool clear. The snails are back in a big way, along with swarms of mosquitoes. Most chemistry indicators were normal summer levels, except surfactants, which were very high at 5.8ppm. Salinity/TDS/conductivity levels were all middling this time – not winter levels, but about double what we typically see in the main channel readings.

 

Wayne Avenue
Outfall volume was moderate, but completely turbid – looked like chocolate milk. Posted pictures via Water WatchDog. Light layer of brown algae on apron. Could not see if fish school was present due to turbidity. Ammonia-N quite high at 0.57 ppm, and total chlorine came in at 1.41 ppm – getting close to residential swimming pool recommended levels. Salinity, TDS, and conductivity levels were about 50% higher than the usual summer levels here. Crows heard nearby.

 

Fleetwood Terrace
Volume was moderate, water clear. Rock algae about 1″ to 2″ long. The seep/slough water level was low, but flow was steady. Surfactant levels were over range, meaning they were more than 8 ppm, a dramatic contrast to the 0 ppm reading in June. Salinity, TDS and conductivity levels were low to moderate. About 25 small fish seen at site. Heard blue jays, catbird, robins and a wren.

While air quality was good at Wayne and Bennington, and a bit better at Fleetwood Terrace, the PM levels were two to four times higher than our best results. Noise levels were a bit higher than usual at each site.

July 2020

Wheaton Lane
Low flow, sand/silt substrate with some black algae. At least two dozen walkers/joggers, and two people at the nearby playground. Ammonia-N (0.22 mg/L) was high this time, part of the pattern at this site (generally, it’s either 0 or it’s approx. 0.22). Water temperature a bit sultry at 25C.  Most pollutants at the low to middle range this time out. Dragonflies, about a dozen blacknose daces, lots of birds nearby. Noise levels low and air quality quite good.

 

Dennis Avenue
Volume low, substrate clean – sand and light silt. Five people at the playground, about a dozen walkers and three children wading and playing extensively in the stream. No fish, macros or insects seen.  Ammonia-N half the level of Wheaton Lane. Surfactant and salinity/TDS/conductivity levels all slightly higher than the upstream site. Slightly noisier, AQ quite good.

 

Flora Lane
Flow medium, substrate sand with white silt on left side.  About 50 smaller fish here, crowding together in scrums at times. Also, a couple adults (about 4″-5″). Water about 2C cooler here, but almost three times as “salty” as Wheaton and Dennis readings. Surfactant levels more than doubled from July’s reading up to 4.4 ppm.  Lots of walkers, joggers and bikers. Water quality very good here, noise levels about 11 dBA higher than Dennis and Wheaton.

 

Dallas Avenue
Volume was moderate but steady. Substrate mostly sand with some silt. Sparrows, house finches, chickadees, about 40 fry and juvies, likely all blacknose dace (some flashes of red – likely male fins?). Ammonia-N low at 0.08, salinity et al. were about twice Wheaton and Dennis; fairly standard here.  About two dozen walkers, joggers, bikers, four teens wading and playing in the restored Clement Street tributary. Air quality and noise levels very good.

June 2020

This is a brief summary of results of chemical and bacterial monitoring at various locations along Sligo Creek.

Dennis Avenue

Volume was on the low side of moderate. Substrate was relatively clear, with some isolated suds floating on surface. More people at this site than we’ve ever seen before, including about 15 children and adults wading and playing in the stream. About 20 fry and juvenile fish (blacknose?) present.  Surfactant and chlorine levels were near all-time lows, but ammonia-N was somewhat elevated.

Flora Lane

Changes since February here. Flow was bigger and clearer, and the substrate was back to its usual sand/gravel clarity. The sediment and mulch of February are gone. About 15 juvenile fish here, as per summer usual.  Surfactant level was less than half of February’s reading, but salinity/TDS/conductivity readings were all about triple those at Dennis Ave. Path was heavily used by walkers, joggers and bikers.

Dallas Avenue 

Volume was moderate and slow. Water striders and blue dragonflies in abundance. A former riffle that is now firmly established as a languid run. Substrate mostly sand with some silt. About 20 juvenile and fry fish, and birds galore – catbirds, grackles, cardinals, crows, about six mallards, a vulture, a phoebe and a robin.  Many data measurements (e.g., salinity, chlorine, surfactants) were about 65% below their February readings.

Bennington Drive

Volume was moderate and clear. The apron had light brown silt and algae combo, but the receiving pool was particularly clear. Maroon algae on the outfall, and no snails – a summer first here. Catbirds, cardinals and about a dozen mosquitoes. Most chemistry indicators were normal summer levels, except salinity/TDS/conductivity, all near elevated winter levels.

Wayne Avenue

Outfall volume was moderate. Channel volume was lower than usual and/or sediment from nearby Purple Line construction has raised the substrate so that the channel appears shallower. The fish are back – about sixty, forty juveniles, fifteen fry, and five larger fish, probably white suckers. No algae on the outfall, which is unusual here. Saw or heard blue jays, red-tailed hawk, and a cardinal. As almost always, this site presented the greatest number of problematic data points, with ammonia-N up at 0.35 ppm, total chlorine at 0.13 ppm, and surfactants coming in above the detection range of the colorimeter – so at least 8 ppm. While monitoring, a grease/oil discharge began, with a cloudy gray plume that the fish all gathered to feed on. As noted below, coliform levels were also extremely high here. Salinity, TDS and conductivity levels were a bit as well, though not as high as Bennington’s numbers.

Fleetwood Terrace

Volume was moderate, water clear. No rock algae apparent yet. The seep/slough water levels were moderate, small isthmus and an island appear to be forming. Blue dragonflies seen there. In the creek, there’s a beaver dam underway (second time in two years). Surfactants were at 0, a dramatic contrast to their 4.7 ppm reading in February. pH was again higher than all other sites, around 8.63. Free and total chlorine levels were a bit high (.07/.15 ppm), especially for one of our main channel sites.  Salinity, TDS and conductivity levels were low.

Air quality was outstanding at every site. Noise levels were as expected at each site except Dennis Avenue, where the number of families enjoying the area bumped sound levels about 10 dBa over their usual range.

February 2020

This is a brief summary of results of chemical and bacterial monitoring at various locations along Sligo Creek.

Wheaton Lane

Volume was moderate, slow and cold. Bottom again covered with thick layer of brown silt and algae. Lots of folks out walking and jogging, along with robins, a downy woodpecker and six whitetail deer. Not all in one group. Detergent level was highest ever here, but chlorine was about half last month’s levels, and other chemical indicators were near standard winter lows. Air quality was quite good and noise levels were slightly higher than usual.

Dennis Avenue

Volume was stronger than usual. Bottom a combo of sand and leaf litter. Chickadee, downy woodpecker and possibly a kingfisher spotted. No tracks seen. Side channel still slowly forming along eastern bank. A few joggers and walkers. All readings were low, except for surfactants, which remain higher than normal. Air quality and noise were very good here.

Flora Lane

Changes here – flow was fuller and slower, with dust or sediment sitting on surface. Also, lots of organic/mulch debris on substrate, which had been probably the cleanest stream bottom that we see. No fish, no birds. Salinity, TDS and conductivity were all about double Dennis Ave readings. Total dropped way down from last month, but detergents continue to increase – up to 5.1 ppm this month. Air quality was excellent, noise levels were slightly lower than usual.

Dallas Avenue

Volume was moderate and slow. Substrate a mix of sand and silt, pool a consistent 2 feet deep now. About a half dozen joggers and walkers. No fish, but mallard pair, robins, and snowdrops starting to bud nearby. pH was high at 8.68, detergents were also high near 5 ppm, and chlorine was particularly hot for this site; .26/.32 ppm, free and total, respectively. Noise and AQ were excellent.

Bennington Drive

Volume was moderate and clear, sharp contrast to last month’s massive sediment discharge. Leaf out beginning, and lots of avian friends heard or sighted, including redtail hawk, turkey vulture, crows and cardinals. Most chemistry indicators were normal winter levels, except detergents – high at 4.4 ppm – and total chlorine, also elevated at .58 ppm. Noise levels were average, and air quality very good.

Wayne Avenue

Volume was moderate. Channel shallower with sand and some rock debris. No fish. Surfactants almost double from last month to 5.5 ppm. Salinity, TDS and conductivity levels were about average for this site. Total chlorine levels were high (.26 ppm). Noise levels nudged up a bit to 58.4 dB. Air quality was very good.

Fleetwood Terrace

Volume was moderate, water clear. No fish seen, algae 2-4″ long. Robins seen, blue jay and pileated woodpecker heard. Bud break underway. The seep/slough water levels were moderate and semi-frozen. Surfactants were elevated for this site at 4.7 ppm. pH was unusually high again, this time at 8.78 (compared to last month’s 8.99). Salinity, TDS and conductivity levels were low for winter. Noise and AQ were both average for this site.

January 2020

This is a brief summary of results of chemical and bacterial monitoring at various locations along Sligo Creek.

Wheaton Lane

Volume was low and cold. Heavy brown silt across bottom, algae about 2″ long. Heard red-tail hawk call, saw deer tracks. A woman who often walks the trail says the water turns “black” during rainfalls, saying she thought it was from car oil or some other fluid. Man and his dog forded the stream and asked about the health of the stream. Readings were fairly low hear, except for chlorine, which was very high compared to the Creek’s mean, especially in winter. Surfactants were low, air quality and noise were very good.

Dennis Avenue

Volume was moderate, light silt and algae. No wildlife seen or heard. Plunge pool is deeper now, with side trib forming along bank. No families or kids in park this time, but a few joggers and walkers. All readings were quite low, except for chlorine and surfactants, which were middle of the range. Air quality and noise were very good here as well.

Flora Lane

Clear, deep, moderate flow here. No fish, no birds. Temperature, salinity, TDS and conductivity were all about double Dennis Ave readings. Total chlorine was high as well. Ammonia barely registered here, as opposed to the zeros at Wheaton and Dennis. Air quality very good, noise slightly higher here than other upstream sites because of Beltway proximity.

Dallas Avenue

Volume was moderate to low; slow current. Substrate clear with some leaf litter. Trib being restored, so pump removing water and shunting around sandbags and curtain, downstream to main channel. No wildlife, no fish, a few pedestrians walked by. Ammonia-N levels at 0, surfactants, salinity, TDS and conductivity levels all fairly low for winter. Perhaps lack of snow and subsequent lack of road salting? AQ was excellent.

Bennington Drive

Volume was heavy and completely turbid with tan-colored silt. Entire spillway, apron and pool opaque. A Water WatchDog event that we are following up on with WSSC and DEP. Ammonia-N levels up to 0.08, surfactants at 0 ppm, which is probably a first. Salinity, TDS and conductivity levels all quite high, and would probably have been higher if we’d taken our sample five minutes earlier. Chlorine levels moderate. Noise levels were moderate, air quality excellent.

Wayne Avenue

Purple Line construction has hit this site. Sandbags and box boulders right up to the outfall. Volume was low to moderate. Channel was shallow with sand and small asphalt pieces in pool and on apron. No fish. Small but steady line of suds from outfall. Ammonia-N levels were high for winter at 0.18 ppm, surfactants at 2.9 ppm. Salinity, TDS and conductivity levels were all seasonally appropriate, i.e., higher than average. Chlorine levels were very high (.14/.26). Noise levels were about 56 dB (a little low here), and air quality was very good.

Fleetwood Terrace

Volume was low to moderate, water clear. No fish seen, algae 2-4″ long. Kingfisher and red-bellied woodpecker seen, blue jay heard. Deer tracks present. The seep water levels were low but steady, surprising given the lack of rain lately. Ammonia-N levels at 0.02, surfactants were up at 3.9 ppm. pH was unusually high at 8.99. Salinity, TDS and conductivity levels were low for winter. Noise levels nudged up a bit to 55 dB. Air quality good here, though slightly poorer than most other sites this day.

December 2019

Dallas Avenue
Volume was moderate; slow current here now, but deep pool (almost 3 ft at our site, which used to be 2 inches in depth). Substrate clear with leaf litter, some plastic trash along edges. Less fine silt than in prior visits. No animals or tracks seen. Ammonia-N levels at 0, surfactants were quite high (5.3ppm). Salinity, TDS and conductivity levels were low for winter. Chlorine levels low, noise as well at 51 dB, quieter than usual.  AQ was excellent. Many walkers out.

 

Bennington Drive
Volume was just above a trickle. Leaf litter heavy, some gray algae, maroon on the outfall. English ivy taken over banks. No snails this time, shrubs and branches blocking much of apron now. Ammonia-N levels at 0.01, Surfactants fairly steady at 2.6 ppm. Salinity, TDS and conductivity levels all near winter highs. Chlorine levels moderate (.07/.09). Noise levels were lowest every (42 dB), air quality excellent.

 

Wayne Avenue
Volume was very low. Channel was shallow with heavy leaf litter in pool. No fish, a few bird calls. Small but steady line of suds along far bank, light plastic trash along banks. Ammonia-N levels were high (especially for winter) at 0.39 ppm, surfactants at 3.1 ppm. Salinity, TDS and conductivity levels were all seasonally appropriate, i.e., higher than average. Chlorine levels were moderate (.08/.08). Noise levels were about 56 dB (a little low here), and air quality was very good, though a smidge higher than the other sites.

Fleetwood Terrace
Volume was moderate, water clear. No fish seen, algae 2-4″ long. Hawk hanging out in overhead tree. The seep water levels were strong, and we’re now seeing through flow to the main channel in most visits. Ammonia-N levels at 0.05 surfactants at 2.6 ppm. Salinity, TDS and conductivity levels were low for winter. Chlorine levels were higher than usual (.15/.07), and noise levels were about 53 dB. Air quality good, about same as Wayne Avenue.

October 2019

Wheaton Lane
Flow volume was moderate. Many joggers, walkers and families at nearby playground. Tons of tracks (raccoon, bird, dog, mouse) and one yellowjacket. About five small fish. Substrate lightly covered in brown algae. Ammonia-N level at 0, while salinity/TDS/conductivity were all quite low. Free chlorine snuck up a bit to 0.04 ppm and surfactants were steady at 1.4 ppm. Noise level was really low (43 dBA), air quality was very good but up substantially from last month’s rock bottom levels.

Dennis Avenue
Volume was moderate. Many kids playing nearby, lots of bikers and runners. Good leaf litter, no algae. Suds present, but likely from leaf breakdown. Ammonia-N level down to 0 mg/L, surfactants down again (2.2 mg/L). Chlorine pretty low, while salinity/TDS/conductivity about 30% higher than upstream Wheaton site.  About 40 small fry, no tracks but many crows and dogs heard. Noise levels around 52 dBA and AQ was good, but higher than Wheaton.

 

Flora Lane
Moderate water flow this time, and no algae, more sand/dirt. About 15 fish, jays, crows and one highly-annoyed squirrel. Ammonia-N way down to 0.04, surfactants down by 30% to 2.3 ppm. Chlorine relatively high (.05/.08 ppm). Conductivity, TDS and salinity were fairly high. Lots of joggers and dog walkers. Noise around 50.5 dBA, AQ very good; same as Wheaton.

 

Dallas Avenue
Moderate flow. Site is now a pool due to Parks’ cross vaning. Substrate has less silt, more sand than last time. Trib coming from Clement Road/Midwood Place area was choked with tan sediment. Sent pic via Water WatchDog. Three or four water striders seen, no fish. Ammonia-N levels at 0 mg/L, surfactants steady at 2 ppm. Salinity, TDS and conductivity about double Dennis Ave site. Chlorine levels back down to .02/.07 ppm. Noise levels were quite low (49 dBA). AQ was very good, about same as Wheaton.

 

Bennington Drive
Flow back in SA11. Volume in SA 10 (measured outfall) was low to moderate. Leaf dam built up across the apron. Apron and pool had no algae, but moderate amount of brown silt on bottom. Ammonia-N levels down to 0.04, and surfactants down to 1.1 from last month’s 6 ppm. Salinity, TDS and conductivity levels were all quite high, close to winter territory again (769/1079/1540, respectively). Chlorine levels were moderate. About 20 snails, some leaf litter. Noise levels down around 48 dBA) and AQ was very good.

 

Wayne Avenue
Volume was low, channel outfall pool very deep. Ammonia-N levels down to .12, after being off the chart last month. Surfactants were down but still high at 4.3 ppm. Salinity, TDS and conductivity levels were all moderately high, as were chlorine levels (.12/.12). About 40 fish, including many large white sucker adults that appear to be almost a foot long. And one titmouse stopped by. Lots of foot traffic and cyclists out. Noise levels at 53.2 dBA (below normal here) and AQ was very good.

Fleetwood Terrace
Volume was moderate. About 7 small fry, fox or skunk smell again. Flow back to main channel from slough, grass showed where Creek had flooded over into the slough recently. Ammonia-N levels down to 0 from 0.26 ppm, surfactants way down as well (0.9 ppm). Salinity, TDS and conductivity levels were midrange and chorine levels were low. AQ was very good but climbing, and noise was lower than usual at 53 dBA.

Wheaton Lane
Flow volume was quite low, almost stagnant. Two dozen small fish, one 5″ crayfish and many water striders. Substrate is lightly covered in algae and gray silt. Ammonia-N level up at 0.25 mg/L. Salinity/TDS/conductivity rising again into fall, free chlorine was relatively low at 0.03 ppm and surfactants were down at 1.4 ppm. Noise level was back to normal around 51 dBA. Air quality was fantastic around 0.1 for PM2.5 and PM10.

 

Dennis Avenue
Volume was lower than normal. Lots of leaf litter and local kids playing nearby.  Ammonia-N level high at .19 mg/L, surfactants as well (2.9 mg/L). Chlorine was more than twice Wheaton’s levels, while salinity/TDS/conductivity were about 20% lower.  About 15 fry, heard several crows. Substrate fairly clean, with little algae or silt. Noise levels around 56 dBA and AQ was outstanding as above.

 

Flora Lane
Moderate water flow this time, and substrate has gray algae, which is new.  Ammonia-N was 0.16, surfactants were 3.8 ppm – very high for this site. Chlorine quite low. Conductivity, TDS and salinity were about 30% higher than Wheaton and Dennis readings.  One small frog jumped in as I arrived. About 20 fish spotted. Heard nuthatch, squirrels, saw a chipmunk. Lots of joggers and dog walkers. Noise around 54 dBA, AQ almost as good as Wheaton and Dennis.

 

Dallas Avenue
Extreme low flow. Riffles are gone. Site is now a pool due to Parks bridge and cross vaning up stream. Substrate covered in tan silt. Water striders in abundance, two fry seen. pH and temperature higher here than up stream.  Ammonia-N levels at .24 mg/L, surfactants also at 2 ppm. Salinity, TDS and conductivity about same as Flora Lane. Chlorine levels high — 0.21 ppm total chlorine. Noise levels were about 54 dBA (a little low here). Construction crew (Sligo pathway and foot bridges) nearby, with lots of walkers and bikers in the area. AQ was perfect (0 PM2.5 and PM10).

 

Bennington Drive
No flow in SA11, which is rare. Volume low to moderate.  Apron and pool had no gray algae, but lots of tan-colored silt on bottom and surface of water.  Ammonia-N levels at 0.12, which is low here but surfactants way up at 6 ppm. Salinity, TDS and conductivity levels were all quite high, close to winter territory. Chlorine levels were relatively low, pH was quite high (8.44). About 20 snails, fair amount of leaf litter, lots of plastic trash – cups, work gloves, bags, a bike helmet and a lacrosse ball. Noise levels were about 51 and AQ was solidly good.

 

Wayne Avenue
Volume was moderate, channel outfall pool very deep. Gray oils/fats obvious in cloudy outflow, ammonia-N levels so high they could not be read by colorimeter. Surfactants were also extremely high at 8 ppm. Salinity, TDS and conductivity levels were all moderately high, as were chlorine levels. Outfall was a complete mess this time around (also see off-the-chart coliform levels below). About 75 fish, including several adults that appear to be a foot long. Lots of foot traffic and cyclists out, as well as two fishers, one quite exercised. Heard blue jays and a pileated woodpecker. Noise levels were about 54 dBA (below normal here) and AQ was very good.

Fleetwood Terrace
Volume was a bit below normal, water clear. New terraces in the channel with lower water level and/or summer blowout rains. About 10 small fish, fox or skunk smell. Heard crickets and many birds.  No fish seen, very little algae. No flow through to main channel from slough, which had dried into 3 small pools. Coliform levels were the highest we’ve ever seen here, in line with Wayne Avenue’s “normal” zone. Wayne’s own levels probably contributed to #s here. Ammonia-N levels high at 0.26 ppm, surfactants slightly elevated (2.6 ppm). Salinity, TDS and conductivity levels were midrange and chorine levels were low. AQ was very good and noise at 56 dBA.

 

Maple Avenue
Volume was light, apron spillway covered in putrid leaves and mud. Sporadic sewage/putrefaction smell mixed with detergent/soap odor. More of apron has collapsed into pool and safe access is now an issue. No flow in 01C. Receiving pool was green/brown opaque. Usual orange floc in 01B, gray algae in 01A. Ammonia-N level in 01A was 0.23 (ran out of reagent for 01).  Surfactants were 1.8 there. Salinity, TDS and conductivity levels were moderate and almost identical. Temperatures were warm for October. Chlorine level in 01A was a bit high at .05/.10 free/total. Mosquitoes and gnats in droves, concentrated near the grills and the rotting leaves on apron. Noise levels were about 58 dBA and AQ was very good.

May 2019

This is a brief summary of results of chemical and bacterial monitoring at various locations along Sligo Creek.

Wheaton Lane
Flow volume was low. Two small fish seen, few birds heard. Substrate is lightly covered in algae. Ammonia-N level moderate at 0.15 mg/L. pH was more basic than usual – almost 9 – but temp was seasonally appropriate. Salinity/TDS/conductivity were low, and chlorine was at 0. Surfactants at 2.8 ppm, about their usual range here. Noise level above normal at 63 dB, but this was because it was mowing day at Parks, apparently.

Dennis Avenue
Volume was moderate to low here. Ammonia-N level at 0.08. Surfactants were about 1.8 mg/L. Chlorine levels lower were .03/.09/.06. Salinity/TDS/conductivity were about 10% higher than Wheaton. We saw about 15 juvenile fish. Substrate fairly clean, with little algae or silt. Noise levels around 61.5 dB, which is high, again because of mowing decks in the area.

Flora Lane
Moderate water flow this time, and substrate was cleaner than usual (no algae, mostly sand). Ammonia-N was 0.11, surfactants were 1.8 ppm. Free and total chlorine were .03 and .10, respectively. Conductivity, TDS and salinity were about double Wheaton and Dennis readings. About 15 juvenile fish spotted. Lots of bird and mosquito activity. Noise around 56 dB.

Dallas Avenue
Volume was low. Substrate clear. No tracks seen, but gnats and juvenile water striders in abundance, and a couple released a box turtle near the bridge (it had crawled up near their swimming pool). Ammonia-N levels at 0.9, surfactants were up at 2.8 ppm. Salinity, TDS and conductivity levels between Wheaton and Dennis readings. Chlorine levels low this time around. Noise levels were about 56 dB. Construction crew (Sligo pathway and foot bridges) nearby, with lots of walkers and bikers in the area.

Bennington Drive
Volume was moderate. Apron and pool relatively clean, though pool column somewhat cloudy. Ammonia-N levels at 0.42, which is pretty high. Surfactants at 1.9 ppm. Salinity, TDS and conductivity levels were all quite high, close to winter territory. Chlorine levels were a bit high (0.14 ppm for total chlorine). No snails, unusual for this late in the spring, but raccoon tracks seen in the apron’s silt. Noise levels were about 51.5 dB.

Wayne Avenue
Volume was high, channel outfall pool was deep. Lots of orange iron floc on the outfall pipe. About 30 fish, mostly juveniles and fry, as well as lots of birds. Ammonia-N levels at 0.16, surfactants at 2.1 ppm. Salinity, TDS and conductivity levels were all high, similar to Bennington Drive’s numbers. Chlorine levels were all fairly low. Noise levels were about 59 dB (normal here).

Fleetwood Terrace
Volume was moderate, water clear. No fish seen, very little algae. Several dragonfly pairs near the seep/slough, where water levels were high and consistent flow through to the main channel appears now to be well-established. Ammonia-N levels at 0.09 ppm, surfactants steady here at 1.8 ppm. Salinity, TDS and conductivity levels were midrange, along the lines of Dallas Avenue. Chlorine levels were quite low, and noise levels were at 55.5 dB.

Maple Avenue
Volume was heavy, covering the entire remaining outfall spillway. Steady flow of sandy sediment from 01A and, to a lesser extent, 01B, through monitoring. 01B has very heavy iron floc throughout, and 01C also has steady flow (which appears to be the new normal for this pipe). Receiving pool was completely opaque with suspended sediment – could not see the bottom. Ammonia-N levels were 0.13 and 0.38, 01A/01B respectively. Surfactants were 2.7 and 0.6 ppm in 01A and 01B. Salinity, TDS and conductivity levels were moderately high and quite similar to one another. Chlorine levels were low in both pipes. Raccoon tracks in apron sediment/algae layer. Noise levels were about 57.3 dB.

Wheaton Lane
Flow volume was low. I disturbed one juvenile fish or tadpole when I arrived. Dog and raccoon tracks along the bank, with birds quite vocal today. Substrate is covered in dark gray silt and heavy algae layer. Ammonia-N level low at 0.06 mg/L. pH and temp were seasonally appropriate. Salinity/TDS/conductivity were high, as would be expected with winter’s road salt application. Chlorine levels were surprisingly high, as were surfactants at 2.6 ppm. Noise level slightly above usual at 51 dBA, air quality in the very good range. Dennis Avenue Volume was moderate to high here, which is interesting since it’s only about half a mile downstream from the Wheaton Lane site. Ammonia-N level at 0.02. Surfactants were about 1.6 mg/L. Chlorine levels lower were about half of those at the Wheaton site. Salinity/TDS/conductivity were about 20% lower than Wheaton and near the standard winter averages. Saw three fish fry, one parent and child playing nearby. Noise levels around 53 dBA – normal here – and air quality excellent (about half Wheaton Lane’s PM2.5 and PM10 numbers).

Flora Lane
The water in this outfall/trib was had full but moderate flow. Substrate appeared to have more algae and fine sand then previously. Ammonia-N was 0.02, surfactants jumped to 3.4 ppm – high for this site, as well as most others. Free and total chlorine were lower than recently at .07 and .11, respectively. Water temp here was about 2 degrees warmer than nearby tribs or the main channel, which appears to be a consistent pattern. Conductivity, TDS and salinity were about a third lower than Wheaton Lane – the opposite of what we saw in November. About 12 juvenile fish spotted. Noise around 53 dBA and air quality excellent (interesting since this site is about 150 m from the Beltway).

Dallas Avenue

Volume was low and slow. Cobbles covered with algae, pebbles and sand clear. No animals or tracks seen. Ammonia-N levels at 0, surfactants halved back down to 1.2 ppm. Salinity, TDS and conductivity levels between Wheaton and Dennis readings. Chlorine levels very low this time around. Noise levels were about 54 dBA, which is quieter than usual. AQ was excellent. Lots of bikers out.

Bennington Drive

Volume was moderate. Apron and pool covered with gray silt/sand + algae still. Ammonia-N levels at 0.18, a substantial jump from last readings. Surfactants fairly steady at 2.5 ppm. Salinity, TDS and conductivity levels were all relatively low for this time of year – about same as Flora Lane. Chlorine levels were lower than most other sites (.02/.03). Few birds heard, snails gone. Noise levels were about 54 dBA, air quality excellent.

Wayne Avenue

Volume was high with a distinct sewage-meets-mildew smell. Channel was shallow, with new sediment appearing to have filled the outfall pool. Lots of orange iron floc on the
outfall pipe. No fish, no birds. Ammonia-N levels at 0, surfactants at 2.6 ppm. Salinity, TDS and conductivity levels were all seasonally a bit low, similar to Flora Lane’s readings. Chlorine levels were split (.03/.21, free and total, respectivley). E.coli was 6,300 and total coliform came in at 8,400 cfu – not as high as usual, but still hot. Noise levels were about 60 dBA (normal here), and air quality was the lowest tested this month – on the line very good and good (23.7 PM2.5 / 40.1 PM10).

Fleetwood Terrace

Volume was moderate, water clear. No fish seen, algae quiet. Lots of crows. Three new beech trees planted by Parks. The seep water levels were lower, but consistent flow through to the main channel appears to have been established. Ammonia-N levels at 0, surfactants steady here at 1.8 ppm. Salinity, TDS and conductivity levels were high – in fact, the highest of all sites. Chlorine levels were lower than usual, and E.coli and total coliform came in about average at 1,000 cfu/1,500 cfu, respectively. Noise levels were about 52 dBA, air quality was on the edge, with roughly the same levels as Wayne Avenue.

Maple Avenue

Volume was very heavy, covering the entire outfall apron spillway. Monitoring here is now more time consuming due to the collapse of most of the apron. Occasional detergent or shampoo smell present. Steady, moderate slug of sand and silt began at precisely 1 PM. Receiving pool was opaque and bottom covered with silt and sand. Ammonia-N levels were 0 at both outfalls. Steady stream of surface bubbles visible in both pipes, though no visible accumulation in receiving pool. Surfactants were 2.2 and 1.1 ppm in 01A and 01B, respectively. Salinity, TDS and conductivity levels were a bit lower than would be expected here in winter. Free/total chlorine levels were quite high in 01A (.29/.60), more moderate in 01B (.10/.16). This appears to be a consistent pattern here. E.coli and Total coliform were much lower than usual 300/400 cfu in 01A, and 200/300 cfu/mL at 01B. Two ducks in distance of Brashears, no animal tracks in apron sediment/algae layer. Heavy peach and iron algae in 01A and 01B, respectively. Noise levels were about 60 dBA, which is higher than usual here. Air quality here also sketchy – very similar to numbers at Wayne and Fleetwood. These last three sites were monitored on a separate day, so these numbers could be simply the result of a change in air masses, or they may reflect geographic patterns. More data will help sort this out over time.

Wheaton Lane
Volume was low and slow. Ammonia-N level at 0, pH and temp were seasonally appropriate (slightly more alkaline and definitely colder, respectively). Salinity/TDS/ conductivity again all extremely low. Chlorine levels were essentially zero. Surfactants still quite high though, at 3.7 ppm. A steady stream of small suds went by. Substrate covered with brown sediment/algae mix. No animals seen. Noise level higher than average at 58 dBA, and air quality very good (PM2.5 at 12.3, PM10 at 21.7).

Dennis Avenue

Volume was low to medium, substrate was surprisingly clean of algae. Lots of suds floating by. No birds hear, one small fish fry seen. Lots of leaf blowers and joggers today. Ammonia-N level at 0. Surfactants around 1 mg/L. Salinity/TDS/conductivity quite low, though slightly higher than Wheaton Lane. Noise levels around 58 dB – again about 5 dBA louder than the prior month. Air quality just slightly worse than at Wheaton Lane.

Flora Lane
Very clear water as always, with a moderate, steady flow and clean sand/silt mixed bottom. Ammonia-N was 0, surfactants crept up to 1.7 ppm. Water temp was a couple of degrees warmer here than nearby tribs or the main channel. Conductivity, TDS and salinity were much higher than readings at Wheaton Lane and Dennis Avenue – more than double. About 12 juvenile fish spotted. Air quality and noise almost identical to Dennis Ave. Rain began and had to end monitoring.

Wheaton Lane
Volume was low and slow. Ammonia-N level way down at 0.01 mg/L. pH and temp were seasonally appropriate (slightly more alkaline and definitely colder, respectively). Salinity/TDS/conductivity again all quite low. Chlorine levels were surprisingly high (free chlorine at .20 ppm). Surfactants still around 2 ppm. Coliform readings were again relatively low here (100cfu EC, 500cfu TC). 1/2″ brown algae covers most rocks on substrate. Water striders common, some small fry fish present. Noise level about average at 48 dB.

Dennis Avenue

Volume was low and slow. Ammonia-N level at 0. Surfactants around 2 mg/L. Chlorine levels lower than Wheaton but still elevated (.10 to .14 range). Salinity/TDS/conductivity quite low though slightly higher than Wheaton Lane a mile upstream. Substrate a mix of brown algae and clean cobble (80/20). No fish seen, lots of parents and children playing nearby, though not in the stream. Noise levels around 53 dB.

Flora Lane
Very clear water as always, with a moderate, steady flow and clean sand/silt mixed bottom. Ammonia-N was 0, surfactants had fallen back to around 1 ppm. Free and total chlorine were quite high at .18 and .26, respectively. Water temp was a couple of degrees warmer here than nearby tribs or the main channel, which is interesting because this trib is shaded for its entire course. Conductivity, TDS and salinity were, again, about twice the readings at Wheaton Lane and Dennis Avenue. Coliform levels were only in the 100 – 300cfu range, so a huge improvement there. About 20 juvenile fish spotted. Noise around 53 dB.

Dallas Avenue

Volume was low and slow. Substrate relatively clear of algae. A handful of small fish seen. Ammonia-N levels at 0.03, surfactants doubled back up to 2.6 ppm. Salinity, TDS and conductivity levels all about 15% higher than Dennis Avenue’s readings. Chlorine levels jumped up (.15/.16). Total Coliform was 900cfu, E. Coli was 300cfu. Few birds. Noise levels were about 60 dB.

Bennington Drive

Volume was heavy, smell of dust or dirt and occasionally soap was present. Apron and pool covered with gray silt/sand. Ammonia-N levels at 0.02, surfactants up to 2.9 ppm. Salinity, TDS and conductivity levels were all elevated for this time of year – 50% higher than Flora Lane’s readings. Chlorine levels were lower than most other sites (.02/.06). E.coli was 0 but Total Coliform was 28,000 cfu – the highest we’ve ever seen here, comparable to Wayne Avenue’s usual readings. Few birds. Snails gone. Noise levels were about 50 dB. Wayne Avenue Volume was steady, water clear but occasionally musty smell appeared. Channel was moderately deep and fairly clear, with lots of leaf litter and about 30 juvenile and adult fish in the pool. Ammonia-N levels at 0, surfactants at 2.3 ppm. Salinity, TDS and conductivity levels were all elevated for this time of year, similar to Flora Lane’s readings. Chlorine levels were lower than most other sites (.03/.05). E.coli was 24,000 and Total Coliform came in at 24,600 cfu – very hot, as usual. Noise levels were about 61 dB.

Fleetwood Terrace

Volume was moderate, water clear. Only 4 small fry fish seen, no evidence of beaver or birds nearby. Ammonia-N levels at 0, surfactants down to 1.6 ppm. Salinity, TDS and conductivity levels were seasonally appropriate similar to Dallas Avenue. Chlorine levels were higher than usual (.12/.11), and E.coli and Total Coliform came in much higher than usual at about 12,000 cfu/100mL. This is a first for this site and there is likely a new source since Wayne Avenue’s high levels are essentially a constant. Noise levels were about 51 dB.

Maple Avenue

Volume was heavy, occasional detergent or shampoo smell present. Sand and silt sediment was all over the apron and coated the bottom of the receiving pool. Ammonia-N levels were 0 at 01A, 0.9 at 01B. Surfactants were 2.4 and 1.6 ppm, respectively. Salinity, TDS and conductivity levels were seasonally appropriate. Chlorine levels were quite high in 01A (.20/.29), more moderate in 01B (.04/.15). E.coli and Total coliform were much lower than readings, ranging from a low of 0 to a high of 1,900 cfu/100mL. Raccoon tracks in apron sediment/algae layer. Someone was getting stoned up one of the tunnels. Noise levels were about 56 dB.

Wheaton Lane
Volume was low and slow, water clear. Lots of water striders here as well as about a dozen tiny fish among the rocks. Short, chocolate brown algae covers most of the substrate. Ammonia-N level at 0, versus .24 mg/L last time around. pH and temp pretty standard, while salinity/TDS/conductivity were quite low again. Chlorine levels slid up to the .02/.04 ppm range, so this is a pollutant that appears to see some variability here. Surfactants were lower at 0.9 ppm. Air quality readings were (4.6 ppm for PM2.5, 4.9 ppm for PM10). Noise level ticked up to around 52 dB. Few birds. Lots of joggers, bikers and walkers, but no one at nearby playground this day.

Dennis Avenue

Flow steady but a bit low, water clear. Short, brownish algae on most substrate rocks. Baby crayfish spotted this time around, along with a handful juvenile fish. Also what appeared to be a northern water snake swam past the site on its way upstream. Grandparents with child splashing through the Creek, many children playing on nearby playground. Ammonia-N was steady near 0.23 mg/L. Water temp slightly lower than Wheaton Lane site, while salinity etc. readings were all about 20% higher. Surfactants were low (less than 1 ppm), while chlorine levels were higher than last month’s reading at .02/.04 ppm. Surfactants came in at 0.9 ppm. AQ levels were poorer than last time around (21.2 and 30.0 ppm PM2.5 and PM10, respectively). Noise levels were up a bit to 57.9 dB.

Flora Lane
Water clear, flow steady, no algae on trib substrate. Ammonia-N was 0, pH was closer to 8 here again, temp was about 3 degrees cooler than the main channel. Conductivity, TDS and salinity were, again, about twice the readings at Wheaton Lane (405, 595 and 850). Surfactants were high again at 3 ppm. Free and total chlorine were at .02 and .03, respectively – holding steady. AQ levels were excellent (4.3 and 10.2, PM2.5 and PM10 respectively), and noise leverls were up about 3 dB to 55.6 dB. About 15 juvenile to adult fish near sampling site, about 20 feet upstream from small waterfall upstream from bridge.

Dallas Avenue

Flow steady but a bit low, water clear. Short, brownish algae on some substrate rocks. About a dozen small fry and juvenile fish. Jay and crow heard. Grandmother with grandson “the scientist” was at site again. Lots of bikers passing by on bridges, a few joggers as well. Ammonia-N levels at 0 – great! – and salinity, TDS and conductivity levels almost the same as Dennis Avenue again. pH slightly closer to neutral than other sites, temperature about the same as the main channel sites upstream. Chlorine levels swapped places with last month (.03/.05). Surfactants remained steady at last month’s reading near 1.3 ppm. AQ levels were 16.2 for PM2.5, 20.0 for PM10 – slightly lower than last month’s numbers. Noise levels were a bit quieter at 56 dB.

Bennington Drive
Water flow strong in SA10, light in SA 11. Light layer of gray algae and/or silt on apron. Less than earlier in summer. Snails back at SA10 – about 50. Water snake living in cracked stones of spillway slope. Lots of trash – cigarettes, plastic bottles, peach Gummi bear wrappers, etc. Receiving pool unusually clear at first, but then flow of suspended sediment and decayed paper or fibers began. Ammonia-N levels at 0.55, so about twice the usual. pH and temp about seasonal standard, while salinity, TDS and conductivity were all higher than normal summer levels (553, 810 and 1147 – getting toward winter levels for dissolved salts, etc.). Free chlorine was very high – .30 ppm – and surfactants were also elevated at 4.0 ppm. Air quality not as good as usual (19.2/26.7 for PM2.5/PM10), and somewhat noisier than normal (58.5 dBA).

Wayne Avenue
Flow moderate, Creek level high (or outfall pipe is sagging). Distinct smell of cedar from outfall, and a small but steady flow of suds. Huge school of fish; about 20 adults (one almost 1 foot long) and almost 100 juveniles and fry. Approx. 85% blacknose dace, 15% white sucker. Ammonia-N at 0.37, pH, temp and the salts about 10% lower than at Bennington Drive. Chlorine quite low, but surfactants moderate at 3.0 ppm. Air quality not as good as usual (20/25.3 for PM2.5/PM10), and sound levels about normal (56.1 dBA).

Fleetwood Terrace
Flow low, water clear, temperature higher than usual, as well as pH. Gray/brown rock algae prominent, 2 to 8 inches long. About 30 fry and juvenile fish. Cicadas quite active. Salinity/TDS/Conductivity all seasonally appropriate. Chlorine levels at .03 ppm, surfactants relatively low at 1.3 ppm. Air quality was poorer here at 22.7/29.3 (PM2.5/PM10) and noise levels were about average for this site (55 dB). Nearby wetland looking strong with dragonflies and extensive vegetation all around. Intermittent flow out of the wetland into Sligo may have been established, at least with average rainfall rates.

Maple Avenue
Flow was moderate here, pool quality was as well. The big news is that the concrete outfall apron or swale has seen its downstream half collapse into the stream. TKPK is apparently looking into temporarily shoring it up before a full rebuild down the road. Raccoon tracks in apron algae, focused on 1C and 1A outfalls. Lots of trash on banks, in forest and downstream. Wood chips/mulch caught in grate of 01B. Tan silt throughout the apron algae mat. Blue jays, robins and crows seen/heard. Water striders in receiving pool, which is unusual here. No mosquitoes, cicadas all around. Ammonia-N was 0.28 mg/L in 01A, 0.48 mg/L in 01B, so higher than usual in 01B. pH, temperature and salts/dissolved salts all comparable to one another and similar to Fleetwood Terrace’s numbers this month. Chlorine a bit high in 01B (0.05/0.07 ppm, free chlorine/total chlorine). Surfactants lower than normal, though higher in 01B. Air quality readings were 19.8/31.1 (PM2.5/PM10), and noise levels were also higher than usual at 61.1 dB.

Except for Wheaton Lane and Flora Lane, PM 2.5 air quality readings this month at these sites pushed the air quality out of EPA’s Good range and into its Moderate area.

Wheaton Lane
This site is in the Sligo Creek main channel about 50 meters south of the headwaters outlet that runs beneath University Ave. Volume was low again, water clear. Ammonia-N level at 0.24 mg/L, approximately background level for many of our sites. pH and temp seasonally appropriate. Salinity/TDS/conductivity again all quite low. Chlorine levels were zeroes this time around, compared to .06 and .08 last time – good sign. Surfactants were still substantial at 2 ppm. Air quality readings were a bit higher than the average for the watershed, but still well within what is generally deemed healthy (14 ppm for PM2.5, 17 ppm for PM10). Noise level about average at 48 dB. Coliform readings were again relatively low here (200cfu EC, 900cfu TC). 1/2″ brown algae covers most rocks on substrate. About 10 fish fry seen. Water striders common, mosquitoes moderate, no tracks along bank mud. Few birds. Lots of joggers, bikers and walkers, but no one at nearby playground this day.

Dennis Avenue
This site is in the Sligo Creek main channel near the Dennis Avenue playground and park building. Flow steady but fairly low. Ammonia-N was up to 0.23 mg/L here. Coliform numbers were about triple the readings at Wheaton Lane. pH and temp slightly lower than Wheaton, while salinity/TDS readings were all slightly higher. Surfactants were low – 1.1 ppm – while chlorine was present this time around, albeit at very low levels (.02/.01). AQ levels were poorer than last time around; comparable to Wheaton Lane’s numbers. Noise levels at 54.3 dB. Substrate a mix of brown algae and clean cobble (80/20). About 10 fry sighted. Mosquitoes very heavy, occasional catbird heard. Large crayfish (9″ body) as well. Parents with children walking along the Creek, dogs cooling themselves and drinking from the stream. Noise lever around 52 dBA.

Flora Lane
This site is near the Sligo Creek bike trail as this trib enters the Sligo Creek floodplain, just west of the footbridge. Very clear water, moderate, steady flow. Ammonia-N was 0.26, surfactants were high (3,1 ppm) again, though lower than last month. Free and total chlorine were at .0 and .03, respectively, so some improvement. pH was closer to 8 here again, temp is a couple of degrees cooler than the main channel. Conductivity, TDS and salinity were, again, about twice the readings at Wheaton Lane. Total Coliform levels were 1600 cfu, and E.Coli was only 200cfu, so better than last time around. AQ levels were poorer here than Dennis Avenue, though still within the “Good” range for AQI. Strong water flow in trib, a fair amount of well-sorted silt, sand and clay on bottom. Mosquito City here. Dragonfiles mating. Vibrant – and fearless – population of juvenile fish (approx 40) who apparently find wading boot fascinating. Noise at 52 dBA.

Dallas Avenue

This site is near the Sligo Creek trail, down the hill from the MNC-PPC headquarters on Dallas Ave, near the footbridges that cross the confluence of the main channel and the Woodside Park trib. Ammonia-N levels at 0.19, surfactants half last month’s reading at 1.2 ppm. Salinity, TDS and conductivity levels almost the same as Dennis Avenues. Chlorine levels jumped up (.05/.03). Total Coliform was again 1100cfu, E. Coli was again 400cfu. Water level low, but clear with good flow. Substrate relatively clear of algae. A handful of small fish seen. Few birds, lots of walkers, including a very young grandson who “is a scientist too.” AQ levels were poorest here (16.7 for PM2.5, 29.6 for PM10) of the four sites. Noise levels were highest at 61 dBA.

April 2018

This is a brief summary of results of chemical and bacterial monitoring at various locations along Sligo Creek.

Bennington Drive
Volume was heavier than usual in SA10. Some dead terrestrial worms on the apron and in the pool, which was very cloudy with suspended sediment. No snails. Lots of convenience store trash (plastic coffee cups, ketchup packets, etc.) this time. Musty, detergent scent occasionally came down the pipe. Apron has a gray algae carpet, outfall now has orange and bright green algae. Birds everywhere. Ammonia-N level low — 0.11 mg/L. pH and temp seasonally appropriate, salinity/TDS/conductivity all near winter highs again. Chlorine levels were low, but surfactants went back up to 4.0 ppm – pretty high. Air quality readings and noise level both very good. Coliform readings dropped moderately from last readings.

Wayne Avenue
Ammonia-N down to a low (for here) 0.29 mg/L, or 1/4 February’s reading. Coliform numbers, however, were much hotter at TNTC. No positive correlation here. pH was a bit lower than usual, and salinity/TDS readings were on the downward spring slope, though still a bit high. Surfactants were down – 2.7 ppm. Steady light suds from outfall pipe and in main channel. Receiving pool was clear with a sandy bottom this time. Birds loud and common, including a pileated woodpecker(?). The fish posse is back – about 20 adults and approx. 100 fry and juveniles.

Fleetwood Terrace
Surfactants were down from February to 1.5 ppm – much improved from winter’s reading of 5.7ppm. Free and total chlorine eased down a bit, ammonia-N held steady at 0.13 mg/L. pH came in at 8 this time, much higher than the sub-4 we saw here last time. Conductivity, TDS and salinity were all low, as was chlorine. Total Coliform levels almost doubled, but E.Coli was almost 50% lower. Gray rock algae 2 to 6 inches long, about 15 fry swimming near sample site. Strong flow in channel. Heard and saw redtail hawks. PM readings snuck up a bit though still excellent, same for dB, now at 55. The Hartford seep is filling with sediment, but also appears to be establishing at least an intermittent flow connection with the Creek now.

Maple Avenue
Flow volume strong in 01A and 01B, as well as 01C, which is apparently no longer unusual. Occasional soap/detergent smell across apron. Ammonia-N levels headed were mixed, both around .15 mg/L. Salinity, TDS and conductivity levels were about average, though 01B is higher on all parameters, including pH (almost 8). Water level in pool was high, quite cloudy from suspended sediment. Delta is only about 2 inches below surface now because of sediment accumulation. Apron now features a highback office chair and more plastic trash than usual. Chlorine levels were lower (0.02 to 0.04 range). Birds common, including robins, blue jays, crows and sparrows. A LOT of trash in stream and along banks. PM AQ levels were excellent, noise levels crept up a bit to 58 dBA.

February 2018

This is a brief summary of results of chemical and bacterial monitoring at various locations along Sligo Creek.

Bennington Drive
Volume was a bit heavier than usual in SA10. Lots of dead terrestrial worms on the apron and in the pool, as well as a fine layer of gray silt. Iron algae was stronger than usual in SA11. Ammonia-N around usual level here — 0.29 mg/L. Temperature and pH were seasonally appropriate, while salinity/TDS/conductivity all near winter highs. Total chlorine was back up to .26 ppm from 0 last month and surfactants continue to drop, though still high. Air quality and noise levels were both good, though a little louder than usual. Coliform was a mixed bag, with E.coli slight lower, but Total coliform rose somewhat, both at levels higher than we’d like to see. AQ excellent, noise at 44 dB.

Wayne Avenue

Ammonia-N shot way up here this time — 1.04 mg/L, or 4 times last month’s reading. This tracks with Coliform numbers which, as usual, are very hot. Surfactants were way down – about 60% drop – which is good news, despite a steady, moderate flow of surface suds during our visit. Receiving pool has more silt than during our last visit, shallowing it up. Lots of crows and cardinals nearby, as well as raccoon tracks, and the outfall fish are back – about 15, mostly adults, including several almost a foot long. Where they go during the winter remains a mystery. AQ excellent, noise at 58 dBA.

Fleetwood Terrace
Surfactants were high (4 ppm), though down from last reading of 5.7ppm. Free and total chlorine were elevated from norms (.10 and .07 ppm, respectively). Ammonia-N was at 0.13 mg/L, which is a bit high for the open channel. pH appeared quite low at 3.52, so we’ll need to follow up next week to see if this accurate. Coliform levels held steady at higher-than-we’d-like range. The beaver dam has been removed. Snowdrops were in full bloom with some crocus mixed in. Suds seen downstream of monitoring site; there were likely from riffles as upstream run section did not have them. AQ excellent, noise at 50 dB.

Maple Avenue

Flow volume strong in 01A and 01B, as well as 01C, which is unusual. Ammonia-N levels headed up to 0.08 and 0.24 mg/L, respectively. Water level in pool was high, somewhat cloudy, though there was no evidence of recent surfactant discharge. Chlorine levels were back to fairly standard levels (0.03 to 0.11 range), well down from December’s astronomical 3.61 free chorine/5.01 total chlorine in KE01B. Surfactants levels were substantially lower as well. Two duck pairs present when we arrived – mallard and wood duck. A LOT of trash in stream and along banks. AQ excellent, noise at 54 dB.

December 2017

This is a brief summary of results of chemical and bacterial monitoring at various locations along Sligo Creek.

Bennington Drive

Salinity/TDS/conductivity all remain near their standard winter highs. Chlorine levels and ammonia-N were zero, which is unusual and welcome. Detergent levels, however, were high (4.7 ppm LAS), though down from last month’s 6.1. Sound levels were low (40 dB) and air readings were good, but Coliform levels more than tripled from November’s readings. No snails, but many birds present. Gray silt in receiving pool now; last month was clean and sandy.

Wayne Avenue

Ammonia-N here was half of last month’s high reading. Salinity, pH and TDS were all slightly below winter averages. Chlorine was low, but detergent level was quite high again (5.6 ppm LAS). Ice surrounded the outfall’s surface waters, including a patch of brownish yellow foam frozen into it. Coliform levels were again extremely high. No fish or birds.

Fleetwood Terrace (main channel)

Water temperature (0.1 C) was noticeably lower than at outfalls. Brrr. Detergents were high at 5.7ppm. Free and total chlorine were elevated (.10 and .07 ppm, respectively). Coliform levels ticked back up to the 1000/2000 ECU level. No aquatic life visible, but a beaver dam is well under way and water level upstream is rising.

Maple Avenue

Flow volume moderately strong in 01A and 01B, no flow in 01C. Ammonia-N levels way down to 0.04 and 0.01 mg/L, respectively. Salinity, TDS and conductivity levels were low, but pH was high (+8). Chlorine levels in KE01A were high, but nothing compared to KE01B (3.61 free chorine, 5.01 total chlorine). These levels are higher than commonly found in swimming pools and hot tubs. Surfactants levels were high in both outfalls as well.

Summary

On the chemical readings, surfactants (soaps/detergents) everywhere appear to remain persistently high. Sediment was not the pressing issue this time around that it has been for much of the fall. On the biological side, as always, Wayne Avenue produces the highest Coliform readings, and we generally saw some increases in Coliform readings, except at Maple Avenue (the chlorine blast being a part of that).

November 2017

This is a brief summary of results of chemical and bacterial monitoring at various locations along Sligo Creek.

Bennington Drive

Volume was moderate at SA 10 with few suds. Salinity/TDS/conductivity were all slightly higher than usual for this time of year. Occasional small suds in current. Chlorine levels were back up, as was ammonia-N (0.26 mg/L). Surfactants level was very high (6.1 ppm), sound levels were down from prior readings (to 43 dB) and air readings were quite clean as usual. Coliform levels were down substantially from October’s reading, but E. Coli tripled. Our snails appear to be gone for the season. Outfall had maroon algae, which i common here. Bird activity was high. Almost no silt or dirt in receiving pool – unusually clean, sandy bottom.

Wayne Avenue

Ammonia-N edged up to the 0.50 mg/L mark. Salinity, pH and TDS were all slightly below fall averages. Chlorine quite elevated (.08 ppm total chlorine), surfactants also extraordinarily high (6.3 ppm LAS). Steady stream of suds down main channel was clearly visible. Light tan algae on outfall’s final 2 feet. Coliform levels extremely high – TNTC (too numerous to count) About 20 fish, all 4 to 8 inches long above leaf litter of receiving pool. Moderate flow in channel. AQ readings slightly higher (worse) than at Bennington, but still within the safe/excellent range. Noise level averaged about 57 dB. No birds seen.

Fleetwood Terrace (main channel)

Temperature was noticeably lower than at outfalls. Surfactants were much higher than usual here as well (3.9 ppm). Free and total chlorine were lower than recent readings (.01 and .02 ppm, respectively). Ammonia-N ticked down to 0.14 mg/L and conductivity, TDS and salinity all remain fairly low. Coliform levels have dropped substantially from mid-summer readings (now 600EC/1500TC). No aquatic life visible, but a great blue heron appears to have made the newly-built seep one of its hunting grounds. Algae covering the rocky substrate, still about 3 to 9 inches long. Moderate flow in channel, currently impeded by a branch and leaf dam that has raised the water level behind it by about 4 inches. PM readings excellent, dB again at 52.5.

Maple Avenue

Pool appeared to have received small detergent discharge just before arrival. Then a 30-minute slug of sediment from 01A outfall began during monitoring. Steady stream of suspended, light tan sediment that clouded the pool brown and filled half the receiving apron. This same light tan colored sediment is clearly visible all across the apron, suggesting this is not an isolated incident. Flow volume moderately strong in 01A and 01B, no flow in 01C. Ammonia-N levels were about double October’s (0.14 and 0.34 mg/L, respectively). Salinity, TDS and conductivity levels were low. Water level in pool was moderate, outfall apron cracks have grown and it continues to tip into the receiving pool. Chlorine levels in KE01A were quite low, but sky high in KE01B (.07 free chorine, .30 total chlorine). Surfactants were high in both outfalls as well, particularly KE01A (3.7ppm). Raccoon tracks in iron algae of KE01A only. A fair amount of plastic trash, leaf dam in 01B. PM AQ levels were excellent, noise levels at about 57 dB, which is normal here.

Park Ritchie

No report made.

Summary

On the chemical readings, surfactants (soaps/detergents) everywhere and sediment at Maple Avenue are the big surprises. On the biological side, as always, Wayne Avenue produces the highest Coliform readings, and we also saw a big spike in the KE01A numbers at Maple Ave in TKPK. Bennington was a mixed bag and Fleetwood’s numbers were a step in the right direction. Please let me know if you have any questions about this month’s chemical or Coliform readings. As always, I will share this with Steve Martin at DEP as well.

September 2017

This is a brief summary of results of chemical and bacterial monitoring at various locations along Sligo Creek.

Bennington Drive

Ammonia-N level was normal for this location. Volume was high from SA 10 with very few suds. pH and temperature as well as salinity/TDS/conductivity were all slightly higher than usual for this time of year. Chlorine levels were quite low, as was ammonia-N (0.11 mg/L). Surfactants were almost half of what they were last time out, sound levels were normal (50 dB) and air readings were extraordinarily clean. Coliform levels down substantially from late June’s reading but are still elevated. May have startled a frog into the receiving pool but can’t be sure. There were about a hundred snails clustered around the SA10 outfall and bird activity was high. An apparently thick layer of silt or dirt or dead algae covered the bottom of the receiving pool. Maroon color on outfall pipe stone.

Wayne Avenue

Ammonia-N remains near the 0.40 mg/L mark. Salinity, pH and TDS all slightly below fall averages. Chlorine slightly elevated, surfactants on the rather high side (3.4ppm LAS). Light brown algae on outfall’s final 2 feet. Coliform levels quite high as usual, but 30% to 50% lower than the summer readings. About 100 fish gathered in radial lines centered on the outfall, everything from fingerlings to adults. Approx. 80% blacknose dace, 20% white suckers. Deep, wide flow in channel. PM readings excellent, dB at about 57, per usual.

Fleetwood Terrace (main channel)

Surfactants were lower (1.1 ppm) than usual. Free and total chlorine are still noticeable (.02 and .04 ppm, respectively). Ammonia-N ticked up slightly to 0.22 mg/L but conductivity, TDS and salinity all remain near the summer lows. Coliform levels high (around 2K), but much less than mid-summer readings. About 2 dozen fish fry present, as well as snails on sandy bottom, tucked just downstream of trailing rock edges. Algae covering the rocky substrate, but it is shorter now, e.g., 3 to 12 inches, than at the height of summer. Deep, wide flow in channel. PM readings excellent again, dB at 52.5.

Maple Avenue

Pool received small detergent discharge just before arrived, then 20-minute slug while we monitored. Trickle of suds came first from 01B, then a move obvious stream came from 01A. Shampoo or detergent scent in the air several times. Flow moderate to strong, including 01C. Ammonia-N levels were low (0.7 and 0.20 mg/L). Salinity, TDS and conductivity levels were low. Water level in pool was high, delta about 12 inches beneath water surface, outfall apron has cracked and begun to slide into receiving pool. Chlorine levels were high (.05 and .04 ppm) in KE01A, while surfactants were high in KE01B at 3.5ppm LAS. Copious raccoon tracks in iron algae of KE01A only. Some plastic trash on apron and stream banks. PM2.5 and PM10 AQ levels were 50% to 100% higher than at other sites, but noise levels were at about 53 dB, which is lower than usual.

Park Ritchie

No report made.

Summary

Our September chemical and Coliform data generally indicate that the Creek’s situation is neither noticeably worsening nor improving compared to previous Septembers. We still see the chronic detergent discharges directly into the Creek from storm water drains along Maple Avenue in Takoma Park, as well as remarkably high levels of Coliform bacteria being discharged from the Wayne Avenue storm water pipe near SSIMS. For at least the past year, we have also seen elevated levels of sediment entering the Sligo Creek system via the Bennington Road tributary, and we continue to see surprisingly high Coliform and chlorine numbers in the main channel. On the positive side, ammonia-N readings are generally flat or down slightly from last year, air quality readings have been excellent, we see somewhat less trash near the pipes and tributary outfalls, and the number of fish and snails present appears to be increasing slightly.

June 2017

This is a brief summary of results of chemical and bacterial monitoring at various locations along Sligo Creek.

Bennington Drive

Last time out (end of April) we had the huge volume with suds and extraordinarily high chlorine readings. This time around, the outfalls were far less dramatic. Ammonia-N levels were average (0.11 and 0.12 mg/L), but salinity, temperature and TDS were all somewhat elevated in SA10. Chlorine levels were back down to their usual range. Surfactant levels were lower than last month, but still in the 3 ppm LAS range. As detailed below, Coliform levels were very high coming from SA10. Receiving pool was somewhat turbid, sediment lessened and water level high, so pool effectively as deep as we’ve seen here. Layer of silt over layer of algae on apron. Flow medium/low respectively (SA10/SA11). PM air quality was excellent, noise level at 49 dB. The snails are back, lots of birds heard, plus mosquitoes. Iron algae absent from SA11; unusual for this time of year.

Wayne Avenue

Ammonia-N remains near the 0.40 mg/L mark. Salinity, pH and TDS all slightly above summer averages. Chlorine at zero, but surfactants were elevated (2.9ppm LAS). Light brown algae on outfall’s final 2 feet. Coliform levels quite high as per usual. About 60 fingerling and juvenile fish, 80% blacknose dace, 20% white suckers. Fewer suds than usual in pipe and main channel, but more trash along banks. Deep, wide flow in channel. Birds everywhere. PM readings excellent, dB at 57.

Fleetwood Terrace (main channel)

Numbers here were pretty standard for the main channel, except surfactants were lower (1.9 ppm) than usual. Free and total chlorine are still noticeable (.03 and .05 ppm). Ammonia-N came in at 0.17 mg/L and conductivity, TDS and salinity all near the summer lows. Coliform levels high (3K to 7K), especially given expected dilution in main channel. About a dozen small fish fry present. Algae covering the rocky substrate, some 2 to 3 feet long. Deep, wide flow in channel so that tree root collars are wet on both sides. PM readings excellent, dB at 53.

Maple Avenue

Pool received small detergent discharge just after we arrived. Laundry detergent scent from 01A easily detected. Flow strong, including 01C. Ammonia-N levels were about half of last month’s, lower than average as well. Salinity, TDS and conductivity levels were low. Water level in pool was high, delta about 6 inches beneath water surface. Chlorine levels, however, were quite high (.09 to .34 ppm) and surfactants were between 1.0 and 2.1ppm. Copious raccoon tracks in iron algae of 01B. Some birds downstream. PM AQ levels excellent, noise levels at about 57 dB.

Park Ritchie

The pool here was as small as we’ve encountered, surrounded by mud filled with deer tracks. Mulch odor was apparent. All levels were extremely high, due to the concentration of pollutants into smaller volume of water. In particular, ammonia-N came in at 1.82 mg/L, chlorine was in the .75 ppm range, and surfactants registered a 6.1 ppm LAS. AQ excellent and noise dB at about 50.

April 2017

This is a brief summary of results of chemical and bacterial monitoring at various locations along Sligo Creek.

In Silver Spring at Bennington Drive Dramatic change to outfall during my monitoring visit. Flow went from moderate volume and clear, to the fastest flow rate I’ve seen here, filled with detergent suds and smelling of chlorine. This large discharge lasted at least 40 minutes. Reported 3 times via WWDogs. Ammonia-N levels were average (0.12 and 0.17 mg/L) but these samples were taken before the slug began (same for salinity, temperature and TDS). Total and available chlorine levels were huge – 20 to 50 times average readings here. Surfactant level was also high (4 ppm LAS), though we’ve seen greater values at other outfalls in the past. Receiving pool clear but shallow because of sediment filling up the bottom. Layer of silt over layer of algae on apron. PM air quality was good. Robins and cardinals everywhere, raccoon tracks, but no snails, frogs, etc.

Ammonia-N levels at Wayne Avenue is back to its normal – around 0.40 mg/L. Salinity, pH and TDS all holding steady at typical spring levels. Chlorine quite low, but surfactants were elevated (2.3ppm LAS). Gray algae on outfall’s final 2 feet. About 70 fingerling and juvenile fish, 80% blacknose dace, 20% white suckers. Birds galore.

Downstream, the Fleetwood Terrace numbers were pretty standard for the main channel, except surfactants were higher (2.7ppm) than usual. This could have been a result of this site being about 200 meters downstream from Bennington Tributary. Free and total chlorine were a bit high, especially given the volume and dilution we’d expect to see in the main channel. Ammonia-N came in at 0.15 mg/L and conductivity, TDS and salinity all near the summer lows. No fish present, but lots of birds heard.

In Takoma Park, the Maple Avenue pool appeared to have just received a detergent discharge – cloudy green color, old suds floating on top. Detergent/hair care scent from 01A easily detected, with hint of cigar/cigarette smoke as well. 01B was mostly cigar/cigarette scent. Flow strong this time in all outfalls, including 01C strongest trickle I’ve seen there. Ammonia-N levels were 01A at 0.20 and 01B at 0.27 mg/L, which is about average here. Salinity, TDS and conductivity levels holding steady around average, chlorine levels and surfactants were highest at 01B – around 2.1ppm. Little algae, no fish, mammal tracks, some birds downstream. PM air qual levels good here as with other sites today. Noise levels average at around 53dB.

No report for Park Ritchie this month, Pat ran out of time.

February 2017

This is a brief summary of results of chemical and bacterial monitoring at various locations along Sligo Creek.

In Silver Spring at Bennington Drive storm water outfalls, salinity and conductivity levels all declined slightly, while the chlorine levels nudged up a bit. The water from both pipes contained more ammonia-N (which is often an indicator of biological matter or waste in the water) than December’s reading. Coliform levels more than tripled at the left pipe (facing up stream), and also rose slightly in the right pipe. and detergent levels both pipes remain high, though slightly lower than our last readings.

Ammonia-N levels at Wayne Avenue’s fell by almost 85% from December’s remarkably high levels (1.14 mg/L). Conductivity, TDS and salinity all held steady, surfactants declined somewhat but remain very high, and chlorine edged up slightly. Coliform levels declined to “only” 30,000 cfus/100mL from the usual “too numerous too count” level. Wayne Avenue’s outfall pipe is consistently quite high for E. Coli and Total Coliform ¬ – far above recommended skin contact levels.

Downstream, the Fleetwood Terrace location – in the middle of the Sligo Creek channel near the parking lot on Sligo Creek Parkway between Wayne Avenue and Piney Branch Road – also saw high levels of Coliform in the water (three to six times December’s readings). Chlorine levels quadrupled and surfactants (essentially, detergents, cleaners, soap) remained stable but high. Most of the rocks on the bottom of the stream in this stretch are now covered with a long, dark gray algae.

In Takoma Park, the Maple Avenue storm water outfalls continue to see visible pollutant discharges of detergents. Ammonia-N levels were low in the left pipe, but almost tripled in the right pipe to 0.29 mg/L. The right pipe also saw a ten-fold increase in its Coliform levels as compared to December’s readings. Conductivity, TDS and salinity readings essentially held steady near recent lows.

The CSO overflow pools behind the Park Ritchie apartments had their lowest water levels that we have seen. All pollutants rose when compared to December’s readings, in some cases by five to ten times. In particular, the southwest pool had a chlorine reading of 0.5 ppm, more than ten times its prior level. These high levels are not unexpected because of the lack of rain and concentration of pollutants in a small bodies of standing water. Coliform levels were lower than normal. Because of the Coliform levels we are finding at our flowing monitoring sites, we would not recommend that you or your pets enter the Creek near these outfalls or the main channel near Fleetwood Terrace at this time or, if you do, we recommend that you wash thoroughly with soap and water after any contact.

Monitoring water quality with the new colorimeter

Above: Water quality team monitoring near Wayne Avenue outfall

Above: Gathering Creek water quality samples near Dallas Avenue

FOSC Chem/Bio WQ Monitoring: Data Sheets

(more data sheets to be added)

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Wheaton Lane testing site

Wheaton Lane testing site

Dallas Ave testing site

Dallas Ave testing site

Bennington Drive testing site

Bennington Drive testing site

Fleetwood Terrace testing site

Fleetwood Terrace testing site

Dennis Ave testing site

Dennis Ave testing site

Flora Lane Testing Site

Flora Lane testing site

Wayne Avenue testing site

Wayne Avenue testing site

Maple Avenue testing site

Maple Avenue testing site

Park Ritchie testing site

Park Ritchie testing site