Everything is relative. It is certainly easier than trying to install a cable connected monitoring system into an already developed area. And it is easier than trying to install a repeater network.
It is also easier now than it was 5 years ago when repeaters were also required.
There are not very many components to a wireless monitoring system. firstly the Gateway. Usually there will only be one gateway required per vacuum sewerage system. The gateway can talk to 20-30,000 nodes and there is no vacuum system or catchment with that number. The area it can look after can be up to 3-4 miles (5 km). The cost comes from where you want to locate the gateway and how high you want to place it. Most clients install it on top of the vacuum pump station, for some it might be on top of the utilities office block. In some towns the Water tower is the highest asset owned by the utility and all antenna’s are placed there.
The other equipment is in the field and the installation work relates to what type of collection pit that you have. The main signals that you want are the valve sensor which is very easy to install (you may need to check.change the magnet within the valve body) a pressure sensor is easy as there is an adapter plate that can be supplied. The high level alarm in the pit becomes trickier depending on what type of pit you have. If it is an older style concrete pit, you are in luck. If it is a Flovac PE pit you are also in luck as there is an access hatch which makes installation easy. (Flovac PE Pit).
If you are installing a high level float into a Fiberglass pit or a molded PE pit then there will be additional work and cost.
Getting the signal from the pit to the gateway, potentially a few miles away is critical to the success of the system. A node which receives the information also has a chip and antenna which broadcasts the information.
Getting the signal from the pit to the gateway, potentially a few miles away, is critical to the success of the system. A node which receives the information also has a chip and antenna which broadcasts the information.
It is far more ideal if the antenna can be placed external to the collection pit. many of the existing pits have cast iron covers which can inhibit the signal strength and although composite covers are easier to get signals through, many vacuum systems are situated in coastal areas or area’s with high water tables that are prone to flooding. Water sitting on top of a pit will certainly affect the signal strength.
There are a few different ways which the antenna’s are being placed externally. One way is by having a cats eye on top of the pit or a fake brick beside the pit which houses the antenna but the issue of flood water is still there. The most common is the use of an external pillar.
A dedicated pillar is used on many projects as a housing structure for the air vent that is required for the correct operation of the vacuum valve. When the valve fires, air enters the pit after the sewage, this air comes from the air vent. Traditionally this came from a gooseneck or candycane vent placed on the homeowners property, which no one liked.
Flovac pioneered the use of dedicated pillars which allowed for a hidden vent to be placed besides each collection pit with no need for infrastructure on peoples properties. These dedicated pillars allowed for housing not only the air vent, but also when in flooded area’s could house the controller and controller breather and now the node and antenna for the monitoring equipment.
Flovac Pillar
There is a cost for running a conduit with the required hoses and wires but this can be done by utility workers. We tend to do 4 or 5 a day. The pillar can be designed to fit in with the local community, people are used to seeing electrical boxes and cable company boxes so trying to make it fit in works well.
If you feel that a pillar would stand out too much then a simple irrigation box would suffice.
There is a cost, it is cheaper than a new valve per pit. And if you look at what the potential savings are, clients have told us that they expect a payback within 2 years or less, then it is well worthwhile. The payback comes from lower energy costs at the station. Less call outs and especially shorter call outs. rather than taking 2 hours to find a problem and 5 minutes to fix, it now takes 1 minute to find the problem and 5 minutes to fix.
The main saving which all managers agree upon is reduced risk. Risk from overflows and risks to operators.
