News from Mission Communications for the Water and Wastewater Professional
Issue 20, Fall 2015
Flow Report Improves Accuracy for Coastal Town
How to Choose the Right Pressure Sensor
Cell Towers and Industrial Equipment Are Hiding in Plain Sight
Enhanced and Expanded Tank and Well Control System



September 28-30
Chicago, IL 
 Week 4: Web Portal II -  Supergraph, Reporting, Volumetric Flow and Advanced Topics
Week 1: Survey of Features
Week 3: Web Portal I - Notification and Unit Setup Options
Week 4: Web Portal II -  Supergraph, Reporting, Volumetric Flow and Advanced Topics
  Week 1: Survey of Features  
  Week 3: Web Portal I - Notification and Unit Setup Options
  Week 1: Survey of Features
  December 9
Week 2: Hardware, Instrumentation and Installation

December 16
Week 3: Web Portal I - Notification and Unit Setup Options


Flow Report Improves Accuracy
for Coastal Town
The Town of Darien is home to 21,000 people on the Gold Coast of Connecticut. Residents pride themselves on being good environmental stewards who work to preserve their pristine waterways and natural habitat. Fred Micha is the Wastewater System Supervisor for the Town of Darien. For three years, Micha has relied on the Mission managed SCADA system for remote oversight of each of their 15 pump stations to ensure proper operation of the collection system. Four of the stations are equipped with M800 RTUs to monitor flow data for monthly reporting.

The main station that sends fluid to the Stamford, CT treatment plant for processing is located near Weed Beach in Darien, CT. Photo credit: Brent E. Wood.

The flow meters are connected to the on-board analog inputs which send real-time, streaming data. Darien officials use the flow data to track the number of gallons of fluid sent to the neighboring Town of Stamford for treatment each month.

Prior to using the Mission system, the pump stations were monitored by Programmable Logic Controllers (PLCs) and phone lines. Micha says the flow report has given them pinpoint accuracy that they lacked with the previous system.

"With the PLCs, there were formulas that altered the flow data and now that we have the Mission system, I realize how gravely off they were," explained Micha. "With Mission, what we're seeing is exactly what we're getting. The flow data that we get now is spot on."

The automated flow report on the web portal makes it easy for Micha to access and utilize the information. The data is available in graph and chart formats. Users can also download the data in CSV or spreadsheet formats. The flow data download function has many options. Users can download hourly readings for a single day, hourly readings for a week, daily totals per month, and daily totals per quarter. Micha uses the monthly flow report which includes daily flow totals, peak flow, and rainfall along with the monthly flow total. He sends the total monthly flow data to the Town of Stamford. The detailed readings can be viewed under Analog Data.

The Flow vs. Rainfall graph shows that 1.5 inches of rain caused flow to increase.

The Flow vs. Rainfall graph is a good tool for analyzing flow data, particularly during wet and dry periods. Often times, flow will increase during rain events which can indicate there are sources of inflow and infiltration nearby. The graph above shows that there was more flow on August 11 than any other day between August 1 and August 20. Flow likely increased due to the 1.5 inches of recorded rainfall. This graph shows flow data for 20 days. To further investigate, we could click on the data point for August 11 to see all of the data for that particular day.    
In addition to monitoring flow, the RTUs at each Darien station monitor pumps, generators, and wet well levels. The real-time data and alarms have reduced overtime and allowed Micha and his team to focus on other tasks.

"This system is invaluable for us because I rely on it solely to operate this department," Micha said. "Without it, we're blind. We go out and check equipment, but when there are moving parts at every station, it's nice to have a reliable system to be your eyes and ears when you're not there."

To take advantage of the flow report, you will need a flow meter that provides an analog output to an M800 RTU analog input. Mission also monitors pulse-based flow meters. Pulse flow data download options include readings every two or 15 minutes that are segmented into 15-minute increments per hour. Feel free to contact our Technical Support team at (877) 993-1911, option 2 for more information on monitoring flow data with your Mission system.

How to Choose the Right Pressure Sensor
Photo by: Dwyer Instruments.
Electronic pressure sensors are used in many applications and vary in range, accuracy, electrical outputs, physical features, and price. They are used with Mission RTUs to monitor system pressure or the level of fluid in a sump or a tank. The most common names for pressure sensors are pressure transducer or pressure transmitter.

Most sensors rely on a piezo crystal that is protected by a diaphragm that moves slightly as the pressure changes. An electric signal is produced that is proportionate to the pressure exerted on the crystal. That signal is wired to an analog channel on the Mission RTU where it is transmitted over the cellular network to our servers. There it is acted on for alarm purposes and made available on various graphs and reports via your web portal.

Factors to Consider When Choosing a Pressure Sensor
When selecting a pressure sensor, the most important factors include output signal, pressure range, and environmental issues. By specifying these variables appropriately you will get good resolution and accuracy.

Determine what type of output signal is best for your application. While there is a variety of possible output signals, 4-20 mA is the most common. An accurate 4-20 mA signal can be transmitted over wires thousands of feet long. It is not easily affected by electrical noise and resistance in the signal wires. Sensors with 0-5 V outputs are often used when source voltages are limited. This is usually the case with solar installations.

Consider the normal operating pressure range and pressure spikes that occur when specifying a sensor. Generally, the pressure transducer should operate between 50 and 80 percent of its full range. This will ensure good resolution. For example, if a transducer is rated for 100 PSI, the ideal operating range is 50 to 80 PSI. Pressure spikes will not only damage the sensing device, but they can burst pipes and seals. It is best to address pressure spikes by selecting a sensor with an appropriate maximum pressure rating to accommodate the spikes while using hydraulic best practices. A pressure snubber can be installed in series with the instrument to smooth the spike seen by the instrument.

Scaling of the transmitted reading is performed at your web portal. For example, a 0-10 PSI transducer can be scaled where 4 mA is 0 PSI and 20 mA is 10 PSI. If that same instrument is located in a pit three feet below ground underneath a 23' ground storage tank, it should be scaled from -3 to 20 feet to show the proper tank level. Some utilities choose to scale their tanks "above sea level" so that comparisons can be made between tanks.

In-line transducers should be protected from freezing conditions. Consider using insulation, heat tape, or oil-filled feed lines to reduce damage due to cold weather. Protective materials must be appropriate for the chemicals that are present.
Electrical Considerations
The electrical basics of a transducer involve simple mathematics. Using Ohm's law (V=IR), the 4-20 mA signal is converted into a 1 to 5 voltage drop at the RTU by way of a 250 Ohm resistor (5V = .020I X 250R). The resistor is in the circuit when the jumper on the Mission main board is in the upper position. Conversely, a 0-5 V transducer directly yields a voltage drop so the resistor is taken out of the circuit when it is placed in the lower position. The wiring of 2-wire, 3-wire, and multi-instrument analog loops is covered in the Option Board Manual.

Color coding of analog wires is not always consistent. The most common mistake is that a 2-wire analog transducer is connected between A1+ and A1-. The power wire of the transducer should be connected to AUX + and the signal wire should be connected to A1+. A1- is used for the common wire of a 3-wire transducer.

Analog spikes can occur because of severe electrical noise caused by the energy dissipated in a dropping magnetic field of a collapsing relay coil. Supergraph can be used to correlate pump stops with analog anomalies.

The well pump flow spiked when the well pump de-energized.

Feel free to contact Mission Technical Support at (877) 993-1911, option 2 for more information on the sizing and scaling of transducers for your application.
Cell Towers and Industrial Equipment
Are Hiding in Plain Sight       
Wireless machine-to-machine (M2M) connections in the United States are expected to grow from 36 million in 2013 to 263 million by 2018, according to the Cellular Telephone Industries Association (CTIA). There are nearly 300,000 cell tower locations today with thousands more expected. Cell tower camouflage is a growing trend as a way to help towers blend with the surrounding landscape.

A cell tower disguised as a palm tree allows vacationers in Fiji to connect to the cellular network. Photo by: Matt Crousillac.

Many municipalities across the U.S. and states like California have ordinances that require cell towers to be as obscure or aesthetically pleasing as possible. These zoning requirements have given birth to creative cell tower disguises. Some of the most common disguises include trees, water tanks, cacti, church steeples, art sculptures, and flagpoles. Some designs are so clever, people are unaware they are looking at a tower.
Duckett Creek Sanitary District (DCSD) housed an MBR treatment plant inside this home in a neighborhood. Photo by: DCSD

Industrial equipment camouflage has been around for decades. As early as the 1950s, electric utilities in Canada built "fake" houses to conceal sub-stations. In recent years, Mission customer Duckett Creek Sanitary District in Missouri disguised a membrane-bioreactor (MBR) wastewater treatment facility by placing it in an 8,000 sq. ft. home in a subdivision.

Larson Camouflage was the first company in 1992 to introduce tower camouflage in the U.S. starting with a Sprint tower that resembled a tall pine tree in Denver, Colorado. Andrew Messing, President of Larson says their mono-pines and mono-palms are the most popular with a typical height of 60 feet for a mono-pine.

"We do a lot of palm trees on the West Coast and pine trees on both coasts," explains Messing. "We have done two different types of palm trees, pine trees, elm trees, and some cacti native to Arizona."

He says his designers consider the surroundings when designing the proper disguise. In one installation, a cell tower was camouflaged to look like a utility pole in a group of other utility poles by strategically mounting components and adding texture to make it look like wood. When designing a mono-tree, antenna "branches" with foliage are attached to mounts to hide antennas and make the tree look more realistic.

Cell tower disguises continue to receive mixed reviews. Some onlookers do not realize they are towers until they are pointed out. Other people say they look unnatural and make towers more obvious because they seem out of place. For example, the tree in the bottom left photo sticks out because it is larger than surrounding trees. The tank in the bottom right photo looks like a real water tank.

Left photograph by: Michel Royon, Right photograph by: Larson Camouflage.

If your city is considering cell tower camouflage, make sure the products conform to communication standards and do not obstruct radio frequencies (RF). Most RF-safe camo products are constructed of fiberglass, epoxy composite, and plastic. Anything made with metal can interfere with RF signals. Cell towers require maintenance from time to time. Project managers should consult with the camouflage company to make sure vital components on the towers will be easily accessible.

Click here to see more photos of disguised cell towers.

Enhanced and Expanded
Tank and Well Control System
The Tank and Well Control system was recently enhanced with a new look and feel, support of up to five well pumps, and a new pump runtime limit feature.

New Look and Feel
The main display on the new Tank and Well Control system includes information that you want to see every day.

The appearance of the interface is the most recognizable change to the Tank and Well control system. It has been optimized to enhance the user experience and utilizes the latest web technology. Operators may now perform control operations through a secure modal interface to enable configuration changes without leaving the main view. Items that are accessed every day are shown on the main display, while items that are viewed less frequently are located in modal windows. All control configurations, as well as system status information is visible on the main interface for a convenient, at-a-glance view of each Tank and Well system.

Expansion to Five Well Pumps
The Tank and Well system was expanded to support up to five well pumps as a result of several customer requests. This expansion allows users to spread water demand over more wells. All pumps can be turned on and off manually or automatically via your desktop or mobile web portal with an administrator-level login. If you would like to add more wells to your Tank and Well Control system, feel free to contact Technical Support at (877) 993-1911, option 2 for assistance.   

Pump Runtime Limits
Mission implemented a feature that allows you to select a maximum runtime for each pump.  Once the first pump reaches the maximum runtime, the system will alternate to the next pump in the rotation. The runtime limit feature is a complement to the existing level production logic where the system analyzes the gallons produced by each well and places the well with the lowest production in the lead pump position. The runtime limit logic was added for a few reasons. Some pump manufacturers specify a maximum continuous pump runtime. Setting a pump runtime limit prevents the pump from overworking according to the manufacturer's specification. It also helps to prevent premature pump wear and tear.

Many regulatory agencies require utilities to run well pumps for a set amount of time each day. It is good practice to evenly distribute pump runtimes across all well pumps. If a well is overworked, it can start producing bad water or lower the water table. It allows wells that produce almost exactly as much water that is consumed to be in rotation with other well pumps that do not run as often. This feature allows pumps to rest and gives groundwater sources time to recover.

"Rain is grace; rain is the sky condescending to the earth; without rain, there would be no life."
~John Updike 
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