Basin Information 

Rich McLaughlin 

to: 

Jesse Pritts 

03/17/2011 05:03 PM 

Cc: 

ryan brown 

Show Details 

History: This message has been replied to. 

Jesse - 

I've attached a summary of info that Ryan Brown has on the site. We are not always sure if 

they put out PAM so the dosing is somewhat unknown, but we didn't put more out if we could 

actually see it. Our interest here has been more on the erosion and modeling side of things, 

but since we were there anyway we have made some effort to get some turbidity control 

treatment as well. The upper basin (#3) drainage area wasn't of interest to the erosion side so 

we have requested that information and I'll forward. We are hoping to add another basin on 

this site soon. 

Rich 

Note: I didn't double check the table of data against what I sent earlier - I had left out some 

storm events w/ only 1 or 2 samples taken. 

-- 

Richard A. McLaughlin, Ph.D. 

Professor and Extension Specialist 

Department of Soil Science 

Box 7619 

100 Derieux Street 

North Carolina State University 

Raleigh, NC 27695 

919-515-7306 office 

919-215-5090 cell 

http://go.ncsu.edu/richmclaughlin web 

http://go.ncsu.edu/estcworkshops training 

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file://C:\Documents and Settings\jpritts\Local Settings\Temp\notesFCBCEE\~web4891.htm 3/30/2011
Wake County I-540 Turnpike Basin Monitoring

Note: Because of the scope of the project I mostly looked at the lower basin. Even though we 

have sampling data for each of the basins, I looked at the upper basin’s mass flow out as that 

would be an addition of sediments that wouldn’t be seen/accounted for by RUSLE2. Therefore I 

don’t have drainage area, soil analysis, etc. for the upper basin. The following information is for 

the lower basin on the site, 11.4 B according to the plans from NCDOT.

Site Size/Drainage Size: Period 9.14.10-12.14.10: 2.54 Acres

 Period 12.14.10-02.03.11: 2.92 Acres

 Period 02.03.11-03.03.11: 2.70 Acres

Predominant Soil Types: 

From Web Soil Survey: 

(MfB2) Mayodan Sandy Loam, 2 to 6 percent slopes, moderately eroded

(MgC2) Mayodan gravelly sandy loam, 6 to 10 percent slopes, moderately eroded

(WyA) Worsham Sandy Loam, 0 to 3 percent slopes

From Soil Texture Analysis of samples from Site:

Sand: 66-74%

Silt: 11-15%

Clay: 15-20%

Site Name

Date 

Collected

Date of Rain 

Event

Average 

Turbidity per 

Storm (NTU)

Average TSS 

per Storm 

(mg/L)

Number 

of 

Bottles

Rain 

(in)

Sediment 

Load (kg)

11.3 C In 11/23/2010 11/16/2010 17020.86777 18323 1 0.33 344.16

11.3 C Exit 11/23/2010 11/16/2010 72.5450668 94.3 4 0.33 1.27

11.4 B In 11/23/2010 11/16/2010 21622.74922 51273 16 0.33 2634.63

11.4 B Exit 11/23/2010 11/16/2010 124.4094669 234 18 0.33 30.93

11.3 C In 12/6/2010 12/1/2010 1276.839918 840.59 1 0.2 3.29

11.3 C Exit 12/6/2010 12/1/2010 70.8348753 68.8 2 0.2 1.27

11.4 B In 12/6/2010 12/1/2010 1716.801822 4985 2 0.2 34.75

11.3 C In 12/14/2010 12/12/2010 331.999872 549 4 0.5 8.24

11.4 B In 12/14/2010 12/12/2010 1011.938172 2467 9 0.5 116.57

11.3 C In 1/4/2011 12/16-17/2010 94.409624 217.34 13 0.58 7.798

11.3 C Exit 1/4/2011 18.8330096 15.7 1 Grab 0.17 0.7456

11.4 B In 1/4/2011 12/16-17/2010 490.9607517 1227.38 17 0.58 78.39

11.4 B Exit 1/4/2011 215.971274 128.2033898 1 Grab 0.17 12

11.3 C Exit 1/13/2011

1/6/2011 -

1/12/2011 72.8893688 168.6

1 0.09, 

0.13 0.638

11.4 B In 1/27/2011 1/26/2011 35.97018253 83.23500238 3 0.39 0.919198232

11.4 B In 3/3/2011 2/4-2/5-2/28/11 739.0911547 1494.929304

24 0.53, 

0.31, 

0.63 125.9761385
More PAM was put out by us on 11.23.10 and 1.4.11 when we collected the samples on those 

days. That isn’t to indicate that PAM was not put out by anyone else at other times.

Rain data: The data for the rain event, 12.16-17.11, is for a storm that occurred overnight 

during that time. The other rows with multiple rain event dates are for multiple events that were 

collected at one time (i.e. every row represents a time that we went to collect samples where 

there was sometime more than one rain event). These rain events are split up in the same order 

as the dates are listed.

Basin 11.3 C Inlet: After samples were taken for the 12.12.10 event the flow data shows 

variable levels between 0.5 gpm to 13 gpm for about 24 hours. I would assume that this would 

be due to water freezing in the bubbling tube or the bubbling tube getting clogged. This could 

also be due to water freezing in the purging tube and the sampler not being able to collect 

samples. Although, with all of these cases being possible, looking at this size storm and 

catchment 4 samples wouldn’t seem atypical.

With regard to the same basin, during the next storm, 12.17.10, a similar instance occurred with 

flows between 14 gpm and 0.05 gpm recorded by the sampler for about 24 hours after the last 

sample was taken. Similar instances could have occurred. Again the catchment area for this 

basin was small.

Basin 11.3C Exit: For the storm on 12.1.10, only two of the bottles were taken during 

that event. The others were taken on 12.4.10 and 12.5.10, a time with insignificant if any rain. 

For the 12.16-17.10 event the reason it is a grab sampler is because there were no samples in the 

sampler for this storm, and the inlet had so many it seemed inconsistent. It isn’t clear why no 

samples were taken but based on the flow and time data it was found the approximate volume 

that passed during this time was 12558 gallons.

On 1.1-2.11 high flows were taken by the sampler. Even though it isn’t known for sure, this 

could easily be from snow melt. It isn’t clear why samples weren’t taken during these flows. 

The half of the sample that was taken is from the first event (01.6.11) and the other half from the 

second event (01.12.11).

Note: Basin 11.3 C was removed according to the plans at the beginning Februrary.

Basin 11.4 B Inlet: Flows for the 11.16.10 storm were as great as 800 gpm. Very large 

flows like this were seen for about 28 minutes and for 14 samples and are unlikely. Normal 

flows were seen for the other two samples taken. There were also significant flows after samples 

were taken between 12 and 1 gpm for about 3 days. 

For the 12.1.10 storm, after samples were taken, flows between 6 and 1 gpm were also seen for 

about 3 days.

After the 12.16-17.10 storm, flows between 1 and 10 gpm were seen for about a week.

11.4 B Exit 3/3/2011 2/4-2/5-2/28/11 170.0351674 319.6384267

21 0.53, 

0.31, 

0.63 48.25529329
From 12.26.10 to 01.04.11 flows between 3 and 12 gpm were seen. This could be due to snow 

melt, but doesn’t explain the lack of samples from this period.

During the 2.4.11 storm flows between 100 and 200 gpm were seen during a majority of the time 

that samples were taken. Based on the flow data, it seems that all the samples were full by the 

middle of the rain on 2.4.11 since flows between 200 and 300 gpm were seen for about an hour 

and a half after which the flow decreased normally for four hours to 20 gpm then increased to 

750 gpm during the next storm and finally decreasing over the course of a couple of days. 

During the last storm on 2.28.11 similarly the flows increased to 700 gpm at the beginning of the 

event and gradually decreasing to minimal over the course of a couple of days.

Basin 11.4 B Exit: 

For the 12.1.10 storm, flows starting at 20 gpm and decreasing to minimal levels were seen over 

the course of 4 to 5 days.

Similarly, for the 12.16.10 storm, flows began at 10 gpm and decreased to minimal levels over 

the course of 2 days.

And again for the 1.2.11 storm, flows began at 13 gpm and decreased to minimal levels over the 

course of 3 days. The estimated volume that passed for this (1.2.11) period was 24659 gallons.

It was at this last collection time discovered that the tubing to take samples was torn apart within 

the housing of the pump.

Flow data is missing from 2.10.11 to 3.3.11. This could be because of a power loss and the solar 

panel recharged the battery so that it would turn on again on 3.3.11.