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Model 403 CMT Multilevel System

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Advantages of Multilevel Systems

Provides the most accurate 3-D assessment of a site

Vital to understanding vertical flow of contaminants

Allow documentation of changes in the concentration and delineation of a contaminant plume

Low cost compared with multiple individual wells

Research has shown that contaminant plumes are often thin and highly stratified. Traditional monitoring wells, with screened intervals of 10 ft. (3 m) or more, blend the groundwater over the entire length of the screen. This can mask the true concentrations and distribution of contaminants. Multilevel wells with short screened intervals overcome this problem and offer more precise identification, better design options for treatment and ongoing monitoring.

CMT Multilevel System

This reliable easy to install and inexpensive multilevel system provides site assessors with a better understanding of the three-dimensional groundwater flow and distribution of contaminants. Remediation strategies can then be targeted more precisely, focusing efforts in the most effective manner.

The CMT Multilevel System makes the accurate monitoring of contaminant plumes much more affordable. It provides detailed vertical as well as horizontal data. The simple 1.7” (43 mm) OD polyethylene tube is segmented into 7 channels, allowing groundwater monitoring at up to 7 depth-discrete zones. Monitoring zones are set where needed and the single tube design allows reliable seals between zones.

Applications

Ideal for shallow wells in high water table

Multilevel water sampling and level monitoring in unconsolidated soils, bedrock or screened wells

Monitoring of natural attenuation or remediation processes

Identify vertical as well as horizontal contaminant distribution with transect monitoring

NAPL, VOC and MTBE Monitoring

Mass transport calculations and mass flux estimation

Determination of the best location for reactive barrier walls

Endorsements

Multichannel Tubing

A multilevel well that uses a continuous length of multichannel tubing has the advantage over other multilevels in that there are no joints. This significantly reduces the time and cost of installing wells and at the same time increases the reliability of the system. The CMT tubing is very simple and convenient to use, as it gives full flexibility as to where monitoring zones are located. Also a single coil of tubing can be used for a number of well installations.

The tubing has a ridge down its entire length to allow for easy identification of specific channels. Ports and packers can be assembled in the field, immediately after drilling the borehole, to reduce open hole time and potential cross-contamination between zones.

Ports

The number and location of ports may be determined in advance, or after drilling the borehole. A Port Cutting Guide is used to cut 2 holes in a vertical line into a given channel, at the specified depth for each zone to be monitored. The plastic between the holes is cut out leaving an opening suitable for inserting a plug, as illustrated above. The plug is positioned and sealed in the channel just below the channel opening.

A vent hole is also placed just below the plug to allow air to escape as the system is lowered into the borehole. This allows water from the monitoring zone to fill the channel below the zone to overcome buoyancy. A stainless steel screen is fixed in place over the port to prevent fines from entering. The screen kits come in a variety of mesh sizes, complete with clamps and plugs. Each channel is sealed at the bottom of the tubing to avoid cross contamination between monitoring zones.

Double-Acting Packers

Double-Acting Packers are ideal for use in situations where a CMT System is in a cased or screened well, or in a smooth rock borehole, and when removal of the system for decommissioning or reuse is important. The Double-Acting Packers have both an inner and an outer gland to seal against the CMT tubing and the borehole. The packers are hydraulically inflated allowing easy removal.

Advantages of the CMT Multilevel

Low cost and ease of use

Up to 7 depth-discreet zones in a single tube

No joints: one smooth surface for easy, effective sealing

Locate ports and packers anywhere along the tubing

Installations completed using alternate sand and bentonite layers are reliable and inexpensive

Double-Acting Packers allow easy system removal

Simple system usually customized and built on site

The hole is not left open to allow cross contamination

Installs quickly in large direct-push casing and bigger holes

One 7-zone CMT System can be completed by two people in under 3 hours.

Minimizes the risk of producing new contaminant pathways.

Monitoring your CMT Multilevel

Water levels and samples can be accurately obtained using the following quality Solinst instruments:

Level: The Mini 101 Water Level Meter is excellent for shallow CMT Systems, in lengths of 30ft, 65ft, 10m or 20m. The narrow 1/4” (6 mm) tape is mounted on a convenient small reel. A narrower coaxial cable Model 102 Water Level Meter may be easier for use in deeper CMT Systems. The 3/8” dia. (10 mm) Druck Pressure Transducer can be used with a data logger for continuous level monitoring.


Sampling:
The Solinst Model 410 Peristaltic Pump which has a suction lift limit of approximately 25 ft (7.5 m).

Model 103 Tag Line
The Model 103 Tagline is ideal for accurate placement of sand and bentonite during borehole completion.

CMT System Components

The tubing is available in lengths of 100ft, 200ft & 300ft (30m, 60m & 90m). The coils are approximately 4ft. (1.2m) in diameter. If deeper multilevels are desired the Waterloo Multilevel System can be considered. (See Data Sheet 401). CMT tubing is laid out on the ground or plastic sheeting for the preparation of ports, and for placement of packers, when used. The 1.7”OD (43mm) CMT tubing has 7 channels. The 6 outer channels are approximately 7/16” ID (11mm) and the smaller central channel is 3/8” (9.5mm). The port screens are held in place using low profile clamps.


Double-Acting Packers are available in diameters to seal 3” and 4” (75 mm and 100 mm) wells. Centralizers can be used to help position the tubing in the borehole to ensure proper sand and bentonite distribution. The base of the system is completed with a Guide Point Port, which functions both as a point for easier installation and as a seventh port when needed. An optional anchor may be added to prevent the system from lifting during installation. The top of the CMT System is completed with a numbered wellhead that labels each channel for easy identification.

Drilling Contractors

Back to the Solinst Main Web Site

Solinst Canada Ltd.
35 Todd Rd.
Georgetown, ON
L7G 4R8

Phone: (800) 661-2023; (905) 873-2255
Fax: (905) 873-1992

E-mail: instruments@solinst.com