Measuring wastewater is one of the most difficult water management tasks that exists. While some wastewater flows are easy to access, others are very hard to measure because they are in open channel conditions and are below grade. If you need to measure below ground wastewater flow, there are a few factors that you need to consider to help you choose the right tool for the job.
With a little preparation, your operators should be able to take the accurate wastewater flow readings that your system needs. Here are a few tips for measuring below ground wastewater flow and advice for installing flow management tools in your system.
Existing Manholes
In some wastewater situations, it’s possible to measure the flow using a vault or an existing manhole. While this is a convenient solution for measuring your below ground wastewater flow, it also results in some complications that you need to consider.
With an existing manhole, your measuring device must fit entirely inside the manhole. This means that the flow will need to be very small, which is often not possible in wastewater applications. If using an existing manhole is your only option for accessing your wastewater flow, you should be sure to use a Palmer-Bowlus flume, a type of flume expressly designed for measuring piped sewer flows.
Packaged Metering Manholes
The majority of wastewater flows will be too large to measure using an existing manhole. In these situations, many wastewater flow management operations choose to use a packaged metering manhole.
A packaged metering manhole is a good choice because your flume will be integrated into the manhole, providing easy flow access. Additionally, your flume can be extended either upstream or downstream using the barrel included in your manhole. Most wastewater operations will find the success they need by installing a packaged metering manhole.
Flow Considerations
Whichever flow measurement operation you choose for your system, you need to think very carefully about the nature of your wastewater flow. For example, wastewater flows need to be both in open channel conditions and subcritical when entering your flume. While this is easy to achieve in sewer systems, it may be more difficult in other wastewater operations.
If the wastewater flow that you need to measure is supercritical, then you may need to install an energy absorbing manhole instead of a standard packaged metering manhole. Before choosing your flow measurement device, fully consider the nature of your flow and if it’s likely that it will need to be conditioned before entering your flume.
The Right Tools for Below Ground Wastewater Flow
Several considerations need to be made before you can successfully measure below ground wastewater flow. In addition to deciding how you will access your flow, you need to choose the right tools for the job. Finding the tools you need to measure below ground wastewater flow is easy when you work with the professionals at Tracom, FRP.
Tracom specializes in offering top of the line fiberglass water management products, and our catalogue features all of the tools you need to measure wastewater flow, including Palmer-Bowlus flumes and packaged metering manholes. Request a quote from Tracom today and start shopping for the flow measurement tools that will best fit your needs.
