Environmental Science & Engineering - www.esemag.com - September 2005
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New take on ancient art of monitoring rivers, streams and sewers

By Gary Fricke

Wireless monitor

For centuries, City engineers have been measuring and quantifying flows in rivers, streams and sewers. In the early days it was as easy as tossing an orange peel into the flow and measuring the time it took to pass from one point to another. Nowadays, as well as monitoring flows, rainfall and surcharge conditions are also required to understand the hydraulic conditions within the sewer collection system.

With the introduction of electronic data recorders and flow meters, water resource managers can make informed decisions based on accurate field data. In most cases, A/V (Area Velocity) flow meters require routine maintenance to clean sensors, replace batteries and download the data. This is generally done every two weeks and may require confined space entry equipment, traffic control and a two to three person crew to complete. With the advancement of radar and ultrasonic flow measurement (non invasive), the need to visit the site is drastically reduced.

Information Management Collection system operators can employ Telogers to monitor all remote wastewater system parameters of interest. Using wireless communications, the remote site data can be forwarded to the operator's host computer network on demand, on schedule (e.g. daily, hourly) or in response to alarm or amplitude exceedance conditions at each site. Typical applications include:

Flow meters - Recorders can monitor flow meters by accepting the analog output signals produced by the flow meter or by digitally interrogating the flow parameters via the flow meter’s data communications port. A battery powered recorder with a wireless modem can be deployed in a manhole or vault with the flow meter, or installed in an enclosure above ground powered by battery, solar or utility power.

Rain gauges - Recorders can directly interface tipping bucket type rain gauges, counting each tip that occurs within user-programmed intervals (e.g. 15 minutes). Because the recorder and communications method consumes very little energy, a recorder and wireless modem can be deployed with rain gauges operating on battery power for extended time periods without maintenance. Data can be forwarded on schedule or more frequently during rain events.

CSO/SSO Surcharge Levels - A standard data recorder intended to monitor water levels in manholes and report by alarm whenever levels exceed user defined thresholds.

Lift Stations - Wastewater lift and pump stations can be monitored with a recorder system providing the operator information on sump level, pump runtimes and flow through the station. Automatic site alarms include sump level overflow, AC power fail, flow blockage, etc.

Water Quality - Recorders can be supplied with water quality sensors (e.g. pH, ORP, etc.) for waste pre-treatment monitoring applications. The recorder, water quality sensors and wireless modem can be deployed entirely underground for permanent applications, or moved from site to site for temporary testing and surveys.

Data Management Service Hetek Solutions Inc. provides a Data Management Service (DMS) for customers who prefer to outsource the data collection and data management functions. This also reduces the customer’s cost and dependence on internal IT personnel and computer resources.

When employing the Hetek DMS, the customer’s remote site recorders will communicate with a host computer at DMS Center. Data can be collected and deposited into a client specific SQL database. This data may then be served up on a customer designed web page in reports defined by the customer.

The customer may also have access to their DMS database by using an Enterprise Client at their facility and logging onto the DMS server over the Internet using a Virtual Private Network (VPN). This permits the customer’s system administrator or data analyst to edit data, add sites and measurements and modify system operating parameters from their office.

Hetek DMS also will receive and process alarm calls. This could be the simple logging of an alarm call in a message log or the forwarding of an alphanumeric message to a paging service provider, cell phone or email address to alert personnel of a remote site problem. The user can select alarm conditions from a menu of choices including external power failure, input signal hi and low level exceedance, battery low, AC power fail, external event triggers, memory nearly full, tamper switch detection, recorder fault conditions, etc.

A remote recorder (RTU) monitors a wastewater flow meter in a manhole. The recorder is connected to an antenna buried in the pavement adjacent to the manhole.

The RTU collects data from the flow meter (typically level, velocity and flow computations) at a userdefined interval (e.g. 15 minutes) then forwards this data to the DMS host computer. The communications path begins wirelessly between the burial antenna and a local cell tower, then via the cellular carrier infrastructure and the Internet to the host. An Internet Protocol (IP) address within each data packet instructs the network routers where to send each packet.

Administrative controls on the Enterprise Server limit access to data to those web site visitors that log on with the appropriate user name and password. DMS customers may provide access rights to their clients to permit them access to information from specific sites, for example a single custody transfer flow meter.

Telogers Enterprise adds three high-performance data management elements to Telogers for Windows: a flow analysis module, a fully relational database and a web module for displaying data on an intranet or the Internet.

Enterprise stores all data from remote sites into a relational database on the server, including all recorder configurations, event logs, site parameters, etc. Any networked computer running the Enterprise Client software (with appropriate permissions) may then access the data stored in the database. Additionally, Enterprise can serve data to networked users operating common web browsers (e.g. Microsoft Internet Explorer) as web pages. This could include any computers connected to the user's intranet, or if desired the Internet.

Website Data Access Telogers Enterprise provides a web module that permits sharing a wide range of information to authorized users, via a corporate intranet or the Internet using web browsers:

Currently, data provided by the Enterprise web module is read only; the user has no access to modify the database or any operational system configurations. A client access control utility is included with Enterprise that permits the system administrator to control data content to authorized parties by user name and password. This would permit, for example, utility customers to gain access to final flow data from flow meters servicing only their communities, while the utilities management and consulting engineer might have permission to view all measurements from all sites.

Common Data Platform A key benefit of the Telogers system is that data from all collection system monitored sites reside on a common data platform. This adds efficiency and economy to the tasks of comparing and reporting the relationships of flow, levels, pump activity, water quality and surcharge events in response to normal operation, rainfall events, system blockages, maintenance activities, etc.

Immediate accessibility to historical and real-time data from all key system monitored parameters during wetweather events allows operators to make informed decisions on how best to respond to system surcharges and overflows. Time correlated data of the consequences of rainfall on system flows, levels, pumps and water quality provide management the information tools to better plan system expansions and emergency preparedness.

Information sharing with associates, consultants, and clients, throughout the utility organization is enhanced when all data is presented in a common format correlated with all parameters of interest.

Hetek Solutions Inc. is the Canadian distributor for Telog Data Recorders.
Contact Gary Fricke at gary.fricke@hetek.com

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