Systematic Analysis of Siphon Operations and Assessment

Systematic Analysis of Siphon Operations and Assessment

Veronica Alvarez| PUG April Monthly Meeting

© 2020 All rights reserved | REDZONE ROBOTICS

OVERVIEW

I. Siphon Basics

II. Siphon Design

III. O&M Issues

IV. Siphon Operations Maintenance

a. Clean first

b. Inspection approach

c. Inspect to clean approach

V. Reports

VI. Project Outcomes

VII. Questions



SIPHONS 101

SIPHON BASICS

• Siphons/depressed sewers and are often referred to in the field as “bellies” or “sags.”

• Siphons navigate wastewater flow in pipelines that are near bodies of water, subways, tunnels, and other fixed utilities.

• Constructed when traditional gravity design is not permissible

• Flow navigates the siphon pipe until it reaches pressurized flow

Solo is the world's first truly unmanned sewer

inspection robot that is radically changing the

way collection system managers approach

operations and management. Typical daily

production rates far outpace conventional

methods. With Solo you never miss a defect.

Field operator variability is eliminated as a

factor influencing data quality. Video captured

by Solo allows the viewer to Pan-Tilt-Zoom an

entire pipe segment in 360 degrees from a PC

in a controlled environment.

SOLO


SIPHON DESIGN

• Siphon design allows for single barrel, double barrel or multi barrel and the number of barrels

• Design is critical for the future life span of the pipe due to its impact on operations.

• A poor design can lead to blockages, sediment build up and direct impacts on minimum velocities that are critical in siphons.












SOLO


DIFFICULTIES ENCOUNTERED IN SIPHON O&M

O&M ISSUES

• ACCESS LOCATIONS

• PIPE MATERIAL

• SILTATION

• DEBRIS TYPE

• PERMITTING

• HYDRANT ACCESS

• CONFINED SPACE REQUIREMENTS

• H2S LEVELS

• BYPASS REQUIREMENTS












SOLO


CLEAN APPROACH

SIPHON OPERATIONS AND MAINTENANCE

• A Clean first approach or clean only approach is typical for lines smaller than 21”

• Pipe material

• Hydro-Vac

• Recycler

• Hydrant access

• High costs for larger lines


• Double barrel siphon; 18”• Siphon had been causing flooding and information on the asset was next to

minimal• Flow was not flowing normally; determined cleaning was necessary right away

to control overflow. • Cleaning was done with Recycler truck to improve production• Diverted flow into other barrels to assist in cleaning and perform post

construction CCTV (traditional)• Cleaning was estimated at 2 weeks; resulted in 6 weeks due to locations of

sediment

• CITY SAN BERNARDINO

PROJECT: CLEAN ONLY












SOLO


INSPECT APPROACH


• Live flow vs no flow

• Number of barrels

• Access restrictions

• Depth of flow will determine which help determine which type of equipment to use

• Inspecting live using sonar

• Combination inspections with laser and CCTV if corrosion issuspected


EQUIPMENT USED


• Traditional CCTV equipment- dewatering needed

• Sonar Equipment- no video inspection

• Video inspection will provide clear visual image of siphon

• Sonar profiling scans provide data that measure the depth of the water in the sewers, and the amount of debris under the water line


• Double barrel 42” VCP siphon; 540 ft in length• Railroad R/W; flood control channel• Restricted access• Previous location of SSO • Inspection was done with Sonar to determine debris volume to send out to

bid• Debris were the result of illegal dumping that and was lodged in barrel 1;

debris was pushed out and flow resumed normally • Job was not sent out to bid since City was able to remove obstruction with

own crews

• CITY LOS ANGELES

PROJECT: INSPECT ONLY












SOLO


INSPECT TO CLEAN APPROACH


• Where budget constrictions are not as tight, an inspect to clean method can be beneficial

• Determine which inspection methodwill be utilized first; typically, sonar ispreferred to avoid dewatering

• Determine debris present

• Determine cleaning locations and what equipment will be used


• 4- barrel siphon; RCP, 61” 370 ft each• Running under waterway• Flow was minimal in one; flow diverted into this barrel to allow for sonar• On 2 barrels where pipe was not running full, both Laser, Sonar, CCTV were

obtained- tagline required • High H2S levels; ventilation and monitoring • Findings: carpet factory upstream had been dumping waste into WW causing

obstructions in barrels• Recycler truck not favorable due to industrial debris; delays in filling water (1hr

one way)• Debris pushed to D/S locations and vacuumed out

• CITY SAN DIEGO

PROJECT: INSPECT TO CLEAN


• Deady Bridge Siphon• 520 Lf 14” and 24” Double Barrel• Operational issues: Traffic Control, Police Escort, time limitations, locations near

highways• Inspections results showed debris levels much lower than assumed; less cleaning

was required• Additional money left over was used to inspect other siphons in district and

clean as needed

• CITY OF CHICOPEE

PROJECT: INSPECT TO CLEAN


DEBRIS MEASUREMENTS

REPORTS

REPORTS


3D SONAR

QUESTIONS


THANK YOU!Veronica AlvarezSW Regional [email protected]


Documents

Systematic Analysis of Siphon Operations and Assessment