Early 4th of July Water Test is very good!

20 June 2018

Cris Henage and I collected our mid-summer water samples Monday June 18, 2018 between 8:50 and 9:20 am.  The results have returned to a very low level in what has been our normal range for the past several years:

#1                        Dock                        5  cfu
#2                        Cedar Fork Creek    6  cfu
#3                        Booker Creek          10 cfu

Caution level is individual reading above 400 cfu, or per-site average above 200 cfu. CFU  = colony forming units per 100ml.

Lake water temperature was 89F/31.5C, at all sites.  The lake water level was up slightly, at the next to the highest step at the spillway.  I had no rain in my rain gauge for 5-6 days preceding this test, the Eastwood Lake weather station reported 0.52 inches for the week ending June 16, 2018

This is our “Independence Day” water sample.  We took it a few days early for the reasons described in the posting with the previous results.  Since there were two of us, we were able to take some additional tests. I try to do this at least once each year.

Our sample sites are somewhat variable, except for the “dock” site which is beyond the swimming beach area.  Two years ago, the docks themselves moved about 15-20 yds. southwest (left) as you face them from the beach.  The “dock” sample site was between the two original dock locations.  For consistency, I have tried to keep that sample site close to the original location.  The old near dock location was close to deepest point in the lake, about 14’ to 14’6” when the lake is at its present full level.  The Cedar Fork Creek site is in the in-lake forebay where Cedar Fork Creek enters the lake, and the Booker Creek site is in the long arm of the lake, about halfway from the beach to the wooded shallows between the lake and the Booker Creek forebay, about even with a flagpole on the shore, 2/3 of the distance from the north shore to the south shore.  This aligns  with the original course of Booker Creek before there was a dam or lake.  There are several springs in the bottom of the lake at the west (left) side of the main bay. These springs contribute cool water that helps maintain the thermocline (layer of cool water) that is noticeable beginning 2-3 feet below the surface.

SECCI clarity readings have improved significantly since the last water sampling.  For the current test, SECCI readings  were

42” at the #1 DOCK site (total depth 10’6”)

36” at the #2 CEDAR FORK CREEK site (total depth 7’5”)

32” at the #3 BOOKER CREEK site (total depth not measured)

The routine SECCI report is taken from the dam, with results that track the #1 DOCK site.

The lake water is very warm.  It is important to remember to shower after swimming or wading because pores tend to be more open when the water is warm, and anything  on the surface (suntan oil, grass clippings, down) can become more of an irritant if it is not rinsed off.

While  we were sampling the lake water, OWASA was at the park, conducting “smoke tests” on the sanitary sewers.  This test is used to determine if stormwater can get into the sanitary sewer. If that happens, there is a chance of sewer overflows.  The storm drain system is supposed to be completely separate from the wastewater (sanitary sewer).  In this case, we are at no particular risk, because everything on the south side of the lake, beyond the first ridge, drains away from the lake, in the direction of EastGate shopping center.

Before about 2004, we had regular problems with the drainage upstream of the lake, but most of that was corrected by the time the Countryside “lift station” on Kenmore Road went on-line to pump wastewater from the northern part of our watershed over the ridge. We have had very infrequent sewage spills in our watershed.  We were notified promptly whenever that happened.. This has not occurred near enough to our watershed to have caused measurable contamination (other than one gasoline spill) in over a decade.  When it did, it cleared quickly, in 1-3 days, mostly outside of the swimming season.  There are two wastewater mains that go under the lake that serve a very localized area near the lake.  They were “sleeved” (lined) as a permanent fix in the 1980s.

Hurricane Fran produced a tremendous amount of rainfall in September 1996, making the lake look like a whitewater rapids.  This was well before any of our modern improvements.  At that time we were concerned about the safety of the water, and had no access to our water test facility (then in Burlington).  OWASA made their lab available to us for the duration of that event.  Our water quality remained consistently safe (bacteriologically),  even when there was no power and most roads were impassable.

Chuck Henage


06.20.18 by Chuck Henage @ 12:23 pm
Filed under: Website| Water Quality Comments: None

Memorial Day Water Test

25 May 2018

I collected our first regular season water samples beginning at 9:19 am on Thursday, May 24 2018.  The following results indicate moderate levels of normal bacterial contamination.

#1                        Dock                       150  cfu
#2                        Cedar Fork Creek    80  cfu
#3                        Booker Creek          90 cfu

Caution level is individual reading above 400 cfu, or per-site average above 200 cfu. CFU  = colony forming units per 100ml.

Lake water temperature was 81-82F/27.0-27.5C, with the lower temperature at the Dock near the swimming beach.  The SECCI clarity reading was 24 inches, up from 23 inches on May 23.  The increase in clarity indicates that runoff from rainwater may be passing through the lake and we are not accumulating silt or concentrating algae at this time.

We had a similar elevated reading one year ago at this time. There was significant rainfall in the week preceding this sampling, as was the case last year. There was only about 0.2 inches of rain in the 72 hours before the samples were taken, and that was better than last year; the test protocol recommends samples not be taken following a rainfall. The weather station at the park: KNCCHAPE91 reported a total rainfall of up to 6.8 inches for the preceding week, although the website that accumulates this information was not reporting either the total rainfall or the elevation of the site above sea level correctly.  The lake dam is at 296 ft. above sea level, and the weather station is about 8 ft. above the water level (304 ft.).  It is reporting its elevation at 500 ft. I had about 4.9 inches of rain in my yard for the same period, and my rain gauge is at 488 ft., and the location is near the North boundary of the watershed.

We sample three sites in the lake:  near the docks, and close enough to the two tributary streams that we can determine if we are getting any significant differential from either source.   The bacteria we monitor lives in the gut of warm blooded animals and is dispersing and dying in the water.  So getting a higher reading downstream is a bit unusual, but it indicates that the event that caused that higher reading has passed.  The bacteria came into the lake from both sources in enough water to move on through fairly quickly.  It is likely that it has cleared our lake system completely by the time you read this report.

I am not planning on doing a retest at this time because we are well below the caution threshold and we have more rain forecast for the next several days. Coordinating getting the samples to the lab in Reidsville is very time sensitive, and often must be done on short notice.  If the rest of June has normal or below normal rainfall, we may take our next regularly scheduled test (week before Independence Day) a few days early.

Chuck Henage


05.25.18 by Chuck Henage @ 4:47 pm
Filed under: Website| Water Quality| Lake & Land Mgmt Comments: None

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