A utility has a problem. Over the years, the number of sanitary sewer overflows is on the rise. Past survey work included a conventional flow metering program, but it did not tell the utility much. Yes, the data said there was excessive inflow and infiltration, but the meters did not reveal where the clear water entered the sanitary pipes. CCTV inspections helped a little, but it's hard to view the pipes actually leaking. There must be a better method, an improved tool set that isolates I & I so that it can be removed at its source.

From this problem, the Flostik monitoring system was developed. Economical, dependable, low-tech meters are placed in the sewer flow at many manholes waiting for wet weather events. With the onset of rain, the meters detect when and where the sewer flow characteristics change using pressure for depth measurement, temperature change, and sensor tilt for velocity detection. These variations point to where the clear water flow enters the collection system.

To better understand how the meters are deployed, the installation techniques, and the simplicity of wireless data collection, click on the The FloCis Approach, and How It Works tabs. 

The FloCis Approach

Isolation of inflow and infiltration is based on a simple premise. Clear water - the Source - enters the sanitary drainage system - the Receiver - via paths of least resistance. Even though the piping might be deteriorated, where no clear water source exists, then that area of the collection system will not act as the receiver of those flows. The path of least resistance falls in two classes, 1) a direct connection from the clear water to the sanitary piping, called inflow, or an indirect percolation of clear water through soils, known as infiltration.

When considering a meter placement program, the Source/Receiver configuration is evaluated in areas of a sewer district troubled by excessive wet weather flows. The storm flow paths, combined with the location of the sanitary collection structures, are determined by field inspections and utility mapping.

A sewer district troubled by excessive wet weather flows, plans a meter placement program by evaluating the Source/Receiver configuration of the collection system. This preliminary evaluation is used to strategically place FloStiks. Once rains begin and data is gathered and evaluated, least responsive areas of the sanitary collection system are separated from highly reactive areas. The non-reactive regions are removed from further metering and the expense of subsequent testing. For better resolution, the "freed up" FloStiks are clustered in the reactive areas. Thus, the utility determines sections that warrant CCTV inspection and subsequent separation work with the following steps.

  1. Meter the collection system through a progression of wet weather events.
  2. Understanding where clear water can reach the sanitary drainage system.
  3. Evaluation of the wet weather flow characterists from data collected by FloStiks.

When looking for inflow and infiltration,
The unwelcome guest is one that arrives early or hangs around late.

How It Works

The FloStik was designed to address a number of important limitations observed with conventional metering systems.

  1. Sensor with mount function combined.
  2. Using an expandable crossbar, unique adjustable clamp, and extendable hanging design, Flostiks adapt to a wide variety of manhole or basin configurations. No custom setups for each manhole type.

  3. No confined space entry requirements.
  4. FloStiks are installed at street level and therefore do not require specific training and equipment, as well as the risks associated with confined space entry into manholes.

  5. Reduced man-hour requirement.
  6. After driving to the manhole, establishing traffic control, and opening the manhole lid, with minimal training it takes two field personnel about 10 (ten) minutes to install a FloStik. This includes initializing the sensor module, mounting the crossbar, extending the hang tube, and positioning the sensor in the flow.

  7. No clog feature.
  8. Because the bottom end of the FloStik curve with the sewer flow, and is not ridgidly attached to hard surfaces within the manhole, debris is swept off the meter tip. After a rain event begins, the feature assures that during the "first flush" in the collection system, the FloStik module is not biased by ragging on the sensor.

  9. No wires.
  10. Because communication with the sensor module is short-range wireless, there are no physical connects to foul or corrode.

  11. Long battery life.
  12. The FloStik sensor module was designed to reduce labor costs; this includes changing batteries. Both the module design and supervisory firmware assure that the FloStik battery will operate for more than 12 months.

  13. Compact design.
  14. Because the sensors and data collect are a single, compact module, the volume of equipment require in the field is greatly reduced, No more large boxes or cylinders with dangles of wires.

  15. Lower Cost.
  16. Most communities struggle to find new moneys for sanitary sewer studies or I & I abatement programs. The FloCis system reduces the metering cost while a the same time increases system wide knowledge about wet weather behavior in a collection system. Understanding where the collection system reacts when the rain begins is fundamental when selecting site specific repairs.

  17. System wide analysis.
  18. The FloStik data is viewed with custom designed FloViz software that allows the rapid comparison of individual meters, clusters of meters along a trunkline, or entire collection basins.

    Once the FloStik meters are deployed, after a significant rain event(s), the data is collected using a Windows Mobile PDA or netbook device. The deployment set is converted from binary to readable data and imported into an SQL database. FloViz queries the database in deployment sets and displays the data set in a 3D chart box for evaluation.

Technical Specifications

FloStik Technical Specifications
Meter Sensors Pressure, Temperature, Accelerometer*
Max depth measurement  11.5 ft. (138 in.)
Accuracy  Depth, 1% FS
Temperature, 0.5°C
Accelerometer 2.5% (0.05g)
Depth Resolution  0.01 in.
Temperature Resolution  0.0625°C
Accelerometer Sensitivity  1024 counts/g
Sample interval  0.5, 1, 2, 5, 10, 15, 30, or 60 minutes
Sample capacity  261,888 samples (approx. 30 months @ 5 min. intervals)
Battery life  >1 year (CR123 lithium)
CPU  Ultra-low power processor
Connectivity  Configure/download via Bluetooth® communication with Windows Mobile (5/6) or Windows XP/Vista/7 device
*Accelerometer is used to indicate velocity in the flow by measuring the sensor angle and wobble or movement. 
Download the FloStik Technical Specifications
Custom Flow Meter Design 3D Model of FloStik Flow Meter

FloStik Modules are available for purchase or lease.
Manufactured in our facility, FloStiks are available for immediate shipment.
Our staff can respond quickly within 24 hours to your request.
We look forward to hearing from you.