Protect Drinking Water
with Continuous,
Unattended Monitoring
A WHITE PAPER ON VOLATILE ORGANIC COMPOUNDSAMPLING USING CMS5000 MONITORING SYSTEM

Introduction
In January 2014, an estimated 10,000 gallons of 4-Methylcyclohexanemethanol (MCHM), an
industrial chemical used to process coal, spilled into the Elk River in West Virginia, USA1. The
spill occurred upstream of the Kanawha County municipal water intake system, contaminating
the water supply of nearly 300,000 people. Large scale chemical spills such as this have drawn
attention to the importance of safeguarding water supplies, especially near municipal watersystem intake locations. While the Elk River spill drew headlines due to its size and scope;
many less noteworthy industrial spills occur regularly along rivers and lakes. In 2014, theNational Response Center (NRC) recorded an average of five spills per week in water systems
around the nation. On the Ohio River an average of 20 spills per month were recorded. (SeeFigure 1.) These spills included gasoline, diesel, cyclohexane, and styrene2.
Figure 1: ORSANCO recorded spills

35302520151050

http://www.orsanco.org/images/stories/files/emergencyResponseProgram/cincinnatidatarequest%20jan%202013%20-%20dec%202015.xls

Ohio River Valley Water Sanitation Commission (ORSANCO)ORSANCO was formed in 1948 to monitor and control pollution in the Ohio River Valley3. They
monitor many biological and chemical markers indicative of water quality. After a spill of carbon
tetrachloride in 1977, the Organics Detection System (ODS) was created in 1978 to ensure
future spills would be detected and identified then immediately notify officials to coordinate
emergency response activities4. A system was devised where daily samples were collected byoperators to monitor volatile organic compounds (VOCs) in surface waters. ORSANCO waseventually able to implement an automated system which provided continuous VOC data.

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Problem
ORSANCO integrated VOC monitoring into the water treatment plant infrastructure of the Ohio
River, the main source of drinking water for more than 5 million people5. ORSANCO monitors
the raw water influent at 16 locations along the river for VOCs. They monitor 30 known toxic
VOCs that are representative of spills that may occur based on the industries that operate alongthe river. (See Table 1.) If a spill resulting in significant levels of VOCs occurs in the river,
ORSANCO alerts state and federal agencies and downstream water utilities to effectively
respond to the situation and mitigate the risk.
Table 1: Ohio River monitoring compound list
Peak #
1

CompoundTrichlorofluoromethaneCAS #75-69-4

R.T.
2:35

2
34

Bromomethane
1,1-Dichloroethylene
Methylene Chloride

74-83-975-35-4
75-09-2

3:03
3:03
3:33

567

trans-1,2-Dichloroethylene
Acrylonitrile
1,1-Dichloroethane

156-60-5
107-13-1
75-34-3

3:51
3:51
4:23

8
910

Chloroform
1,1,1-Trichloroethane
Carbon tetrachloride

67-66-3
71-55-6
56-23-5

5:49
6:10
6:30

1112
13

1,2-Dichloroethane
BenzeneTrichloroethylene

107-06-2
71-43-2
79-01-6

6:54
6:54
8:18

14
15
16

1,2-Dichloropropane
Bromodichloromethanecis-1,3-Dichloropropylene

78-87-5
75-27-4
10061-01-5

8:48
9:28
10:39

17
18
19

Toluenetrans-1,3-Dichloropropylene
1,1,2-Trichloroethane

108-88-3
10061-02-6
79-00-5

11:33
12:12
12:43

20
21
22

Tetrachloroethylene
Dibromochloromethane
Chlorobenzene

127-18-4124-48-1
108-90-7

13:06
13:50
15:42

23
24
25
26
27
28

Ethylbenzene
1-Chloro-2-fluorobenzene*
StyreneBromoform
1,1,2,2-Tetrachloroethane
1,3-Dichlorobenzene

100-41-4
348-51-6
100-42-5
75-25-2
79-34-5
541-73-1

16:06
16:35
17:31
17:54
19:09
21:08

29
30

1,4-Dichlorobenzene
1,2-Dichlorobenzene

106-46-7
95-50-1

21:20
22:04

31

Hexachlorobutadiene

87-68-3

26:06* Internal standard

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Early water monitoring efforts by ORSANCO employed manual sample collection techniques
and the transfer of those samples to a benchtop gas chromatograph (GC) for analysis. (SeeFigure 2.) This approach is not only cumbersome and time consuming, but may compromise thesample integrity as well. ORSANCO investigated options for automated sampling systems
designed to collect samples at timed intervals. Automatic sampling offered the advantage ofmore regular and frequent sample collection than that of manual sample collection.
Figure 2: Benchtop gas chromatograph with purge and trap sampling system and4
automatic sample collector

https://archive.epa.gov/emergencies/content/fss/web/pdf/schulte.pdf

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SolutionORSANCO installed the INFICON CMS5000 Monitoring System at select locations on the Ohio
River, for automated, unattended monitoring of VOCs in the Ohio River. (See Figure 3 and 7.)
The CMS5000 Monitoring System is a self-contained system utilizing GC technology forcontinuous, unattended, remote monitoring of air or water. It rapidly analyzes VOCs in waterusing a modified EPA purge and trap concentrator protocol. No sample preparation is required.
The state-of-art SituProbeTM purges VOCs from a continuous water stream, collects them on aTri-Bed carbon concentrator, and then desorbs them to the GC for analysis. The Micro Argon
Ionization Detector (MAID) provides sensitive detection of organic compounds having anionization potential of 11.7 eV or below. CMS5000 has:••••

low consumable loadargon tank lasts approximately 4-6 months
toluene permeation tube has an 6-8 year lifespanMAID detector source has a 96 year half-life

Figure 3: CMS5000 installed at ORSANCO site in Midland, Pennsylvania, USAPage | 5A water source can be piped directly into the CMS5000 flow vessel, continuously providing
water samples to the instrument. ORSANCO customized the flow system design to allow for
grab samples; and allow calibration and verification standards to be easily introduced. The
compact wall mounted design of the CMS5000 allows for easy integration into pre-existingwater treatment infrastructures. CMS5000 is capable of detecting all of the ORSANCO
compounds of interest with a detection limit of 1 ppb or less. (See Figure 4.)

Response

Figure 4: ORSANCO 1 ppb calibration standardRetention Time in min.
Column—DB-624 30 m, 0.32 mm ID, 1.8 µm df, Conc. Fill: 1 min.
GC Temp. Profile—50°C (hold 5 min.) to 90°C at 4C/min., to 180°C at 10°C/min. (hold 30 s) to50°C at 25°C/min. (hold 1 min. 30 s)

A DB-624 column was selected to separate the compounds of interest, and a 30 minutetemperature programmable method was developed. Five point linear fit calibration curves werecreated using the results from these standards. All calibration curves have a Percent Relative
Deviation (%RSD) of 10% or less. The method is calibrated from 1 to 10 ppb. The calibration
remains stable over a long period of time, and only requires calibration every 4-6 months.
Calibration accuracy is monitored using a check standard method, which samples from an
onboard toluene-filled permeation tube. (See Figure 5.)

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ResponseFigure 5: Toluene Check Standard

Retention Time in min.
GC Temp. Profile—50°C (hold 1 min.) to 160°C at 20°C/min.

The toluene permeates at a constant rate, providing a stable concentration for every checkstandard method run. The toluene check standard response is used to compensate for seasonal
water temperature changes and normal detector sensitivity fluctuations. Notable changes in one
or more of these parameters may serve as an indication that preventive maintenance is needed
to ensure data quality is kept within acceptable limits. As an additional test of calibration
accuracy, ORSANCO performs a daily continuing calibration verification (CCV) using a standard
that contains a subset of the 30 compounds of interest. (See Figure 6.)

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ResponseFigure 6: ORSANCO CCV Standard

Retention time in min.
GC Temp. Profile—50°C (hold 5 min.) to 90°C at 4°C/min., to 180°C at 10°C/min. (hold 30 s) to50°C at 25°C/min. (hold 1 min. 30 s)

Using I/O or Modbus, CMS5000 can be integrated into many existing networks such as SCADAsystems. Alternately, CMS5000 can upload data directly to a centralized server. ORSANCO
was able to easily establish communication using Modbus protocol.
An automated method sequence controls the instrument to analyze raw water influent every twohours. Each analysis creates a data file, which is saved on both the CMS5000 and an on-sitecomputer. A NEXSENS data logger pulls the data files from the computer and uploads them toa centralized server. If one or more of the compounds of interest exceeds the alarm limit of2 ppb, the server sends e-mail alerts to ORSANCO personnel. If further confirmation is required,additional samples are collected and analyzed using Gas Chromatograph/Mass Spectrometer(GC/MS). CMS5000 systems were implemented at several points along the Ohio River (SeeFigure 7.) The ORSANCO Emergency Response Program responds to an alarm based on theconcentration level and the toxicity of the detected compound. They will then coordinate withthe appropriate government agencies to quickly manage the situation.

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Figure 7: Current Organic Detection System (ODS) instrumentation

https://archive.epa.gov/emergencies/content/fss/web/pdf/schulte.pdf

Conclusion
Using a CMS5000 Monitoring System with purge and trap technology to continuously monitor
river water at multiple locations is an effective way to detect chemical spills and intercept
contaminated water from entering municipal water system intake locations. The stable detector,
data integration capability, low consumable load, and onboard check standard methodology all
make the CMS5000 Monitoring System the ideal instrument for remote, unattended monitoring.

References
1. Centers for Disease Control and Prevention, 2014 West Virginia Chemical Release.
Accessed August 24, 2015.
http://emergency.cdc.gov/chemical/MCHM/westvirginia2014/
2. Luncan, Travis. 2014 NRC Spill Report Summary. Accessed May 8, 2015.
http://www.orsanco.org/images/stories/files/emergencyResponseProgram/cincinnatidata
request%20jan%202013%20-%20dec%202015.xls
3. Ohio River Valley Water Sanitation Commission. About-Us. Accessed May 8, 2015.
www.orsanco.org/about
4. Schulte, Jerry. ORSANCO ODS/Emergency Response Program. EnvironmentalProtection Agency Archive Documents. Accessed May 8, 2015.
https://archive.epa.gov/emergencies/content/fss/web/pdf/schulte.pdf
5. Ohio River Valley Water Sanitation Commission. River Facts/Conditions. Accessed May
8, 2015. www.orsanco.org/factcondition

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