Granger‑Hunter shows nozzle selection, hose disinfection during sewer‑cleaning demonstration

Granger‑Hunter Improvement District operators demonstrated sewer‑cleaning techniques and equipment at a public “sewer summit” field demonstration, focusing on choosing nozzles for different pipe sizes, managing recurring trouble spots and a hose‑disinfection system mounted on cleaning trucks.

The demonstration matter-of-factly addressed why crews change nozzles and adjust flow rates: smaller nozzles and lower spray angles help pull hose and fight uphill flow, while larger “floor cleaner” nozzles and specialty cutters are used for large‑diameter pipes, grease and root removal. Presenters also showed a disinfectant‑injection device they said has been mounted on their trucks for about a year to spray hoses as they are pulled back from manholes.

The demonstration was presented by Granger‑Hunter operators identified during the session as Bruce (senior operator), Dave (CCTV foreman), Jimmy (operator/presenter) and Diedrich (operator who started a truck). Organizers said the session was intended for operators and municipal staff and included live truck demonstrations so remote attendees could view nozzle behavior and hose handling.

Why it matters: choosing the correct nozzle and flow conserves water, extends equipment life and can help crews find and remove partial blockages — preventing future backups and property damage, the presenters said. They stressed that careful observation of the hose as it returns and swapping nozzles when signs of roots or grease appear can reveal problems before a line becomes heavily obstructed.

Most frequently discussed operational points were pipe size, nozzle angle and flow rate. Presenters said typical cleaning targets were 6‑ to 10‑inch laterals and mains; some crews reported work on pipes up to 36 inches, with one attendee noting experience up to 42 inches. For surface coverage they demonstrated a 30‑degree nozzle for full‑surface cleaning and a 15‑degree nozzle when crews need more pulling force to drag hose uphill. Truck flow rates discussed ranged from about 60 gallons per minute (gpm) up to the trucks’ 80‑gpm rating; presenters said crews sometimes run lower than maximum to conserve water while still cleaning effectively.

Specialty tools were shown for grease and roots: a so‑called “warthog” or heavy‑duty root/grease nozzle for aggressive cleaning, chain cutters and saw blades for heavier root intrusions, and a variety of skids and centering devices. Presenters advised matching skid length to pipe diameter — for example, using at least an 8‑inch skid on an 8‑inch pipe — to help prevent nozzles from flipping and to protect liners.

The team demonstrated a mounted disinfectant system (identified in the session as the Vanguard system) that injects a liquid into the hose as it is retracted. Bruce said the system has been on their trucks about a year and that it sprays a disinfectant onto the hose and the immediate area around the manhole to reduce odor and bacterial exposure for operators. Presenters said the device made the hose come back cleaner and reduced odor during laundry‑day loads, and they discussed practical issues such as hose length, rubbing on vehicle components and minor installation adjustments.

Presenters also discussed common local trouble spots: grease buildup in food‑service and lower‑income rental areas, bellies in the line (sags that trap solids), and root intrusion. They said some lines require frequent maintenance — weekly to quarterly, depending on the location — and that consistent hot‑spot maintenance helps prevent backups and property damage.

The session included safety reminders: operators should avoid standing directly over manholes during demonstrations because of spray and nozzle pressure, and centering/skid devices help prevent a nozzle from flipping up out of a manhole. Attendees were shown how to observe small signs on the hose — such as fine root hairs — that indicate an impending blockage and when to call CCTV crews for follow‑up inspection.

No formal policy actions, votes or funding decisions were taken during the demonstration. The event was a practical training and information session; presenters encouraged attendees to adopt asset‑management practices (confirming pipe size and material before arrival) and to keep a variety of nozzles and cutters available for the range of problems crews commonly encounter.

The demonstration concluded with thanks from the host to Granger‑Hunter staff for bringing equipment and leading the hands‑on session. Attendees were invited to examine trucks and ask operators about specific nozzle setups and disinfectant plumbing.