Gheith, Hazem

Dr. Gheith is the Practice leader for collection systems planning and modeling at Arcadis. He has over 35 years of engineering experience. He has developed many tools to support the full spectrum of modeling and planning of collection systems, including data auditing and automatic calibration to hydrologic and hydraulics models. He developed the Model at the Source modeling approach, which integrates the surface and subsurface water movements to develop integrated plan improvements to mitigate street flooding and sanitary overflows.

Titles from this speaker

Description: Alternate: Taking WaPUG to a New Practical Dimension: Introducing an Innovative H/H...

Alternate: Taking WaPUG to a New Practical Dimension: Introducing an Innovative H/H Model Validation Tool

Abstract

H/H Models are the main tool for evaluating and improving the performance of collection systems. Flow prediction quality to variety of storm levels is important to ensure optimized improvements. Maintenance and design activities are expensive and cost-effective improvements is very proportional to good model prediction quality. WaPUG model validation criteria and variety of its form have been widely used to qualify models. Model performance is assessed through a few metrics that determine if the model is closer to observation at acceptable level, including peak flow, volume of flow and the flow depth. WaPUG also states that the observed and model flow hydrographs should closely follow each other in shape. An envelope of acceptable range for the significant peak flow events is the most commonly acceptable criteria. But the open questions remain: what is the acceptable envelope range, how many events within the envelope is required, and how close the hydrograph shape is considered good? In many cases, the goodness-of-fit based on peak and total volume does not guarantee good estimate of overflow volumes or confirm the model prediction is applicable to all seasons. This study presents an easy to use H/H Model Validation tool that overcomes these WaPUG limitations. The H/H Validation Tool reads the observed and model hydrographs and segregate each of them into base flow (dry weather flow with seasonal variation) and storm flow. It then uses user-defined parameters to split the data into individual storms and perform automatic metrics to qualify the model prediction quality at a deeper level. The few automatic metrics include: 1. Visual representation of model quality is replicating dry weather flow conditions throughout the data period by finding maximum and minimum four consecutive base flow days in each month. 2. A procedure to calculate the maximum flow generated within various sliding time spans of each event. The time spans represent the collection system reaction to three distinct flow period: the flow conveyance period to confirm the model quality to be used for pipe capacity studies, the flow storage period targeting the model quality to be used for offline storage studies, and the treatment period targeting the treatment volume at the treatment plants. 3. Present the maximum volume regression comparisons for the conveyance, storage, and treatment periods for all storm. These regression plots give an easy visual indication on the model prediction quality of each event's shape. 4. A heat map comparison for each event. This heat map gives a quick visual understanding. of the events level and their quality of fit. 5. A calculation for the Pearson Correlation Coefficient (the leaner association to the best fit line) and the Concordance Correlation Coefficient (how far from the perfect agreement line) to assess the goodness-of-fit to each metric. The H/H Model Validation Tool provides an easy to use model quality review platform. It eliminates the need for lengthy model review process and does not require the use of any model platform. Comparison results are obtained in few minutes and presented in visual format that is easy to present to variety of stakeholders.

This paper was presented at the WEF Collection Systems Conference in Detroit, Michigan, April 19-22.

SpeakerGheith, Hazem

Presentation time

10:45:00

11:15:00

Session time

10:45:00

11:15:00

Session numberALT

Session locationHuntington Place, Detroit, Michigan

TopicInfiltration/Inflow, Innovative Technology, Modeling

Author(s)

H. Gheith

Author(s)H. Gheith1; J. Barton2

Author affiliation(s)WEF Member Account1; WEF Member Account2

SourceProceedings of the Water Environment Federation

Document typeConference Paper

PublisherWater Environment Federation

Print publication date Apr 2022

DOI10.2175/193864718825158348

Volume / Issue

Content sourceCollection Systems

Word count16

Description: Blueprint Columbus: Comprehensive Public and Private I/I Reduction Program Exceeds...

Blueprint Columbus: Comprehensive Public and Private I/I Reduction Program Exceeds Target

Abstract

This paper provides an overview of the planning analysis, implementation steps, and the Inflow/Infiltration (I/I) reductions achieved by the City of Columbus at the conclusion of its pilot public and private I/I reduction program. The City's integrated plan, "Blueprint Columbus," targets the reduction of Sanitary Sewer Overflow (SSO), manhole flooding, and water-inbasement (WIB) incidents, aiming at a 10-year Level of Service (LOS). The City adopted the "Model at the Source" hydrologic and hydraulic (H&H) modeling approach to identify and quantify I/I sources, and to plan for the required I/I reduction to meet the LOS. The modeling approach quantified the contributions from the various I/I sources such as house foundations, lateral sewers, and sewer mains, and was used to plan the extend of the required I/I reduction technologies. The actual reduction needed to mitigate the SSO and basement backup conditions up to 10-year flow recurrence storm event condition was determined to be 28%. The integrated plan report projects a 40% reduction in I/I during a 10-year historical storm flow level, assuming the City of Columbus lines 90% of the main sewers and lateral house connections, redirects 50% of the house roofs' drainage away from house perimeters, and installs sump pumps in 25% of the residences. In 2015, the Clintonville Main 1 (CV1) basin was selected as the pilot area for the I/I reduction program. In the CV1 area, 95% of the main sewers were lined between 2007 and 2014, and 91% of the lateral sewers were lined between 2018 and 2021. Based on the implementation plan, 95% of the lateral sewer lining was extended into private properties up to the 4"x6" house connections. From 2018 to 2021, roof drainage was redirected to the street for 55% of the roof drainage area that were previously causing water accumulation around houses. Additionally, storm sump pumps were installed in 22.5% of the houses between 2016 and 2021. Post-monitoring analysis for the CV1 pilot study area confirmed the effectiveness of the Blueprint Columbus program. Post-rehabilitation condition models were calibrated using postrehabilitation monitoring data. The 10-year flow recurrence historical storm revealed a median peak flow reduction of 41%, surpassing the planned I/I reduction target outlined in the 2015 Integrated Plan report. The most impactful technology was the lining of the laterals between the sewer mains and house connections. The installation of sump pumps demonstrated limited effectiveness due to the lack of foundation drains and restrictions on installation locations within basements. The redirection of roof drainage proved beneficial, although its effectiveness was compromised in a few basins due to the poor condition of house gutters.

This paper details Columbus City's 'Blueprint Columbus' pilot study to reduce I/I to mitigate SSO and basement flooding. Using a 'Model at the Source' approach, various I/I sources were identified. Specific remedial technologies, including lining of mains and lateral sewers, redirecting roof drainage, and sump pump installations were planned and implemented from 2014 to 2021. Post-rehabilitation monitoring confirmed a median peak flow reduction of 41%, exceeding the project's target.

SpeakerCheng, Fang

Presentation time

11:30:00

12:00:00

Session time

10:30:00

12:00:00

SessionPublic and Private Rehabilitation Strategies for I/I Reduction

Session locationRoom N426b - Level 4

TopicCollection Systems, Intermediate Level, Wet Weather

Author(s)

Cheng, Fang

Author(s)F. Cheng 1; H. Gheith 1 ; Q. Lu 2; F. Cheng 1;

Author affiliation(s)City of Columbus 1; ARCADIS 1 ; ARCADIS 2; City of Columbus 1;

SourceProceedings of the Water Environment Federation

Document typeConference Paper

PublisherWater Environment Federation

Print publication date Oct 2023

DOI10.2175/193864718825159189

Volume / Issue

Content sourceWEFTEC

Word count12

Description: Planning Public and Private I/I Reduction Program that Ensures Performance and...

Planning Public and Private I/I Reduction Program that Ensures Performance and Maximizes Participation for The Region of York

Abstract

This paper presents a comprehensive public and private Inflow and Infiltration (I&I) reduction pilot program implemented by the Regional Municipality of York. The program aimed to maximize private property participation. The Region employed a Model at the Source hydrologic and hydraulics (H&H) modeling approach to identify and quantify the sources of I&I. A 37- hectare residential area in northeast Newmarket, Ontario was used as a pilot study area. The modeling approach identified the sources of I&I, including mains trenches, lateral houseconnection trenches, house foundations, and maintenance hole lids. The H&H model was calibrated to the Region’s downstream permanent flow meter data and updated to represent the system’s condition after the application of several proposed I&I reduction technologies. The Region’s 25-year four-hour design storm was used to predict I&I reductions. A 33% reduction in peak flow and a 34% reduction in I&I volumes were predicted during the first 24 hours of the storm event when replacing or lining the house laterals from sewer mains to house connections. Continuous simulation for one year demonstrated a total volume reduction of 23%. The modeling approach also revealed that redirecting half of the splashing roof leaders away from house foundations could achieve an additional peak I&I reduction of 21.3% and a volume reduction of 12%. Alternatively, assuming foundation drains exist and can be connected to sump pumps, the modeling approach indicated that installing sump pumps in 25% of the houses could lead to a peak flow reduction of 24% and a volume reduction of 11%. Minimal impact on I&I reduction is indicated from plugging the pick holes of the maintenance manhole lids. Overall, this paper highlights the success of the comprehensive I&I reduction program in the Region, showcasing the effectiveness of various remediation measures on the private side and identifying further improvements to reducing I&I effectively. The private side I&I reduction pilot program is used by the Region to scale up to other locations by adapting a similar modeling approach and applying lessons learned from implemented I&I reduction activities

This study discusses a successful I&I reduction program at the Region of York, Ontario using the Model at the Source planning approach. The planning approach identified I&I sources and evaluated effectiveness of reduction techniques. It is predicted that 33% peak flow and 23% volume was reduced over a year. The paper offers a scalable model for similar initiatives in other regions.

SpeakerGheith, Hazem

Presentation time

11:00:00

11:30:00

Session time

10:30:00

12:00:00

SessionPublic and Private Rehabilitation Strategies for I/I Reduction

Session locationRoom N426b - Level 4

TopicCollection Systems, Intermediate Level, Wet Weather

Author(s)

Lu, Qiuli