Ayyeka Sigfox IoT sensors monitor sewage deep underground San Francisco

The San Francisco Public Utilities Commission recently conducted a Smart Sewer pilot with Ayyeka to explore how sensors could monitor waste water

Ayyeka Sigfox IoT sensors monitor sewage deep underground San Francisco

San Francisco depends on a thousand miles of sewers to keep the city running smoothly.

The city collects up to 500 million gallons of waste water in a day when it rains. This waste water is transported to one of three treatment plants where pollutants are removed before being discharged into San Francisco Bay.

Processing sewage is challenging in San Francisco because the city has the Pacific Ocean on three sides of it. During storm conditions, groundwater and storm water can overload the sewage system. Physical, chemical and biological processes remove contaminants from the waste water. This produces environmentally safe water and sewage sludge as a byproduct.

How can sewage conditions be monitored with the pipes deep underground? What kind of sensors can operate in such harsh conditions for extended periods without requiring fresh batteries? How much waste water is in the pipes, how fast it is flowing and what is the level of contaminants?

The San Francisco Public Utilities Commission (SFPUC) recently conducted a Smart Sewer pilot with Ayyeka to explore how IoT could help.

Ayyeka IoT sensors monitor waste water

Sea water seeping into the sewers increases salinity and conductivity. By measuring conductivity, it's possible to measure the amount of sea water that has seeped into the sewage system. Ayyeka's Wavelet Wastewater Quality Kit measured the inductive conductivity and salinity of the waste water. Other Ayyeka sensors measure:

  • Turbidity: the cloudiness or haziness of a fluid caused by large numbers of individual particles that are generally invisible to the naked eye
  • ph level: a numeric scale used to specify the acidity or basicity of the wastewater
  • Oxidation reduction potential (ORP): a measure of the cleanliness of the water and its ability to break down contaminants
Ayyeka Ayyeka

How the Ayyeka Wavelet Discharge Kit communicates

Ayyeka’s Wavelet Discharge Kit uses contactless radar and ultrasonic technology to continuously monitor waste water. Sensors are hardwired to Wavelet devices to communicate over the Sigfox wireless (LPWAN) network to a hub. Sigfox uses a wide-reaching Ultra Narrow Band (UNB) signal that passes freely through solid objects. This is ideal for utilities because it traverses layers of dirt, concrete and other obstructions. The Ayyeka Wavelet uses two communication channels: 

  1. Sigfox for real-time communication: This is ideal for communication underground and with low-power requirements.
  2. Cellular communications: This provides redundancy and allows data backup, remote configurations and upgrades.

The hub communicates to the Ayyeka cloud via a cellular or satellite connection. Data from the cloud is integrated with SCADA systems (via OPC and DNP3) or through an API with third-party software systems.

The Smart Sewer Pilot

Low-power Ayyeka devices in the pilot measure spikes in waste water conductivity and tide conditions. With this, SFPUC was able to set alerts to monitor the waste water quality and get real-time notifications. This, in turn, helps with regulatory compliance, reducing labor costs.

“By combining cellular communication with Sigfox’s low-power communication technology, Ayyeka’s Wavelet transforms the way dispersed assets are monitored. Wavelet uses the best of both worlds, generating data from remote assets, like the deep sea, and dark assets, like manholes and underground wells, where no one has transmitted before,” said Ayyeka CTO Dr. Yair Poleg.

Efficient sewage processing keeps cities working smoothly. Coastal cities such as San Francisco have the added challenge of dealing with tides and old infrastructure. Ayyeka's remote monitoring solutions keep the City by the Bay beautiful (and smelling fresh).

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