Lukas, Andy

As Brown and Caldwell's National Wet Weather Practice Leader, Andy is engaged on strategic projects across the country that are driven by state and federal consent orders related to wet weather compliance issues. He provides solutions on issues ranging from flow metering, hydraulic modeling, I/I reduction, system planning, overflow reduction, and long-term capacity assurance. He has earned B.S., Civil Engineering, University of Wisconsin at Platteville, 1990 and M.S., Civil Engineering, University of Washington, 1995. Andy is a registered professional engineer in the State of Wisconsin.

Titles from this speaker

Description: Not the regular Kool-Aid: How to implement a cost-effective I/I rehab plan under...

Not the regular Kool-Aid: How to implement a cost-effective I/I rehab plan under extreme drought conditions with significant operational challenges

Abstract

The HRSD is currently implementing high-priority projects in two service areas of Portsmouth, VA, as part of the 2020 Regional Wet Weather Management Plan (RWWMP). These projects aim to cost-effectively reduce infiltration and inflow (I/I) in the gravity sewer and manholes to meet the Consent Decree's (CD) sanitary sewer overflow reduction goals. However, identifying I/I in one of the most leak-prone areas has been a significant challenge due to frequent surcharge conditions in the collection system and below-average rainfall in 2022, which has led to the lowest groundwater levels in the past five years. Figure 1 shows the history of flows, rain, and groundwater level conditions over the last 6 years. Figure 2 shows the rainfall event characterization over the flow monitoring period. The I/I hot spot area in Portsmouth, VA includes the historic district near the Naval Hospital and the area upstream of HRSD's Camden Ave. pump station. These areas have been under investigation since July 2022. Over 33 flow monitors have been deployed across these areas to characterize I/I in different parts of the system. Various sanitary sewer evaluation survey (SSES) techniques have been employed to identify the sources of I/I and recommend necessary sewer rehabilitation measures. Figure 3 shows the project area, the flow monitoring locations and sanitary sub-basin delineation and Figure 4 shows a sample of the SSES techniques applied to understand I/I in the system. Unlike most traditional I/I rehabilitation projects, HRSD's objective was not merely to eliminate I/I, but to understand the most effective way to reduce SSOs in line with the goals of the CD. This is particularly remarkable given that HRSD is implementing I/I reduction and capacity improvements on assets they do not own. This arrangement was established through a Memorandum of Agreement (MOA) with all local municipalities during the RWWMP development, aiming to achieve SSO reduction in the most cost-effective manner. Consequently, the project approach involves a comprehensive hydraulic analysis of the service areas to understand I/I behavior and determine whether capacity improvements could be a more beneficial investment for achieving the ultimate goal of eliminating SSOs for an agreed level of service. This paper will present key insights from flow monitoring and SSES investigations that could be beneficial to numerous utilities across the country. The topics covered include: -Flow Monitoring in Pre-Rehabilitation Conditions: This section discusses the effects of dry/wet weather on flow data quality, temporary blockage impacts, sewer response to mild intensity tropical events, flow evaluation under surcharge and backwater conditions, and the influence of sediment/debris/rags on flow sensors. It also covers the selection of flow monitoring equipment and the operation of vacuum-assisted sewer systems, among other pertinent observations. -Traditional SSES Applications: This part focuses on NAASCO's MACP-compliant manhole inspections, smoke testing, and main sewer line CCTV inspections conducted as per NASSCO's PACP criteria. It uses two different types of dye testing: the traditional method where dye water is supplied to a suspected area and visual observation in the sewer confirms the I/I connection, and flooding dye testing where dye water fills nearby stormwater infrastructure and a CCTV camera in the sewer looks for pipe defects where dye enters the sanitary system. The paper also discusses lateral simulated rainfall testing, which can be a cost-effective approach when dealing with private property I/I. In addition to the conventional SSES methods, HRSD is exploring two cutting-edge SSES techniques: -Distributed Temperature Sensing (DTS): This technique involves placing a fiber optic at the bottom of the main sewer lines to detect the presence and exact location of potential I/I sources along the pipe where installed. This method can be especially beneficial in narrowing down the scope of rehabilitation on private property. To visualize the useful information gathered with this technique an example plot is shown in Figure 5 during a tropical storm Ophelia in September 2023 when I/I inputs were colder than the wastewater flow in the sewer at that time -Improved In-Situ Manhole Leakage Test: This innovative technique, a spinoff from an earlier manhole leakage test called by HRSD as the 'Rocket Launcher'. This technique simulates a flooding condition on top of the manhole while maintaining a water surface elevation of 6 to 8 inches over the manhole rim in a wide area around the manhole as shown in Figure 6. The ponded, dyed water infiltrates all around the manhole, activating I/I at various points. Cameras placed within the manhole during the test record the accumulation of volume over time and observe exact I/I entry points. Unlike the previous technique, the leakage rate is calculated as the manhole fills inside while all connected pipes are plugged. Compared to other SSES methods, this new manhole leakage test provides a comprehensive quantification of leakage rates from different parts of the manhole under controlled, replicable conditions. This allows for proper prioritization of I/I contributions from manholes across different zones of the collection system. High-resolution video capture before, during, and after the test offers an excellent qualification of I/I defects inside the manhole. This can be used to identify the necessary scope of rehabilitation, saving significant capital when qualified I/I sources are grouped and full manhole surface rehabilitation is not required. The complete paper will elaborate on the utilization of flow monitoring data, the choice and order of various SSES techniques employed for the project and share some of the outcomes with their implications on the proposed rehabilitation scope of work. A compilation of quantitative and qualitative evidence from work in Portsmouth, VA will be presented to better illustrate this approach's advantages. This demonstrates that HRSD is achieving the Consent Decree's objectives while significantly reducing capital expenditure compared to the original comprehensive rehabilitation estimated by the RWWMP.

This paper was presented at the WEF Collection Systems and Stormwater Conference, April 9-12, 2024.

SpeakerLukas, Andy

Presentation time

10:15:00

10:45:00

Session time

10:15:00

11:45:00

SessionInflow and Infiltration

Session number30

Session locationConnecticut Convention Center, Hartford, Connecticut

TopicCIP Development, Collection Systems, Infiltration/Inflow, Manholes, Rehabilitation, SSO Reduction, Utility Management

Author(s)

Toro, Carlos

Author(s)C. Toro1, A. Lukas1, C. Wilson1, P. Hubbard2

Author affiliation(s)Brown and Caldwell 1; HRSD 2

SourceProceedings of the Water Environment Federation

Document typeConference Paper

PublisherWater Environment Federation

Print publication date Apr 2024

DOI10.2175/193864718825159400

Volume / Issue

Content sourceCollection Systems and Stormwater Conference

Word count21

Description: Pin Point Proof: Innovative Temperature Study Accurately Locates Potential Sources...

Pin Point Proof: Innovative Temperature Study Accurately Locates Potential Sources of I/I

Abstract

Brown and Caldwell (BC) recently performed the first known United States-based study of a sanitary sewer system using Distributed Temperature Sensing (DTS) to find significant sources of infiltration and inflow (I/I) that were active during wet weather events. The study was performed within the East Bay Municipal Utility District (EBMUD) service area and the field study was funded significantly by EBMUD.

Brown and Caldwell recently performed the first known United States-based study using Distributed Temperature Sensing (DTS) to find significant sources of infiltration and inflow (I/I) that were active during wet weather events. The study was performed within the East Bay Municipal Utility District (EBMUD) service area and funded significantly by EBMUD. This study showed the capabilities of the DTS method for finding potential significant sources of I/I in a sanitary sewer system. Confirmation of these findings in the EBMUD study will be needed, but the temperature data provide strong evidence for identifying the locations most likely responsible for observed I/I.

SpeakerLukas, Andy

Presentation time

14:00:00

14:20:00

Session time

13:30:00

15:00:00

SessionFinding and Removing I/I

Session number301

TopicCollection Systems

Author(s)

Andy Lukas

Author(s)A. Lukas1; M. Metcalf4; C. Dinsmore3; R. McDonald5; C. Peters6; M. Davis7; E.M. White2;

Author affiliation(s)Brown and Caldwell, Milwaukee, WI 1EBMUD, Oakland, CA2,3Brown and Caldwell, San Diego, CA 4Brown and Caldwell, Walnut Creek, CA 5,6Brown and Caldwell, Boston, MA 7East Bay Municipal Utility District7

SourceProceedings of the Water Environment Federation

Document typeConference Paper

PublisherWater Environment Federation

Print publication date Oct 2021

DOI10.2175/193864718825158050

Volume / Issue

Content sourceWEFTEC

Word count13

Description: Preponderance of Evidence: Advances in Using Distributed Temperature Sensing to...

Preponderance of Evidence: Advances in Using Distributed Temperature Sensing to Locate and Quantify Sources of I/I

Abstract

At WEFTEC 2021, Brown and Caldwell (BC) presented a paper on the first United States-based study of a sanitary sewer system using Distributed Temperature Sensing (DTS) along a fiber optic cable to identify specific locations of significant I/I sources active during wet weather events with cold I/I conditions. BC has now performed additional studies in the City of Wauwatosa, Wisconsin, with funding from the Milwaukee Metropolitan Sewerage District (District). The District's Wauwatosa study was performed in the summer of 2020 during several significant storm events when I/I was warm compared to background wastewater conditions. The District study provided sufficient data for quantifying actual I/I discharges and proved the technology was capable of working successfully in warm I/I conditions.
Description of Technology
The principle of DTS operation is fairly simple: when laser light passes down a fiber optic cable, the bulk of the energy is passed through; however, a small percentage is reflected back to the source by defects within the fiber optic cable. These defects occur throughout the length of a fiber optic cable. Most of this reflected energy is equal to the transmit frequency, but a small portion is shifted in frequency due to interaction between the laser light and the defect. Some energy is shifted higher in frequency, and some to a lower frequency. The intensity ratio of higher frequency energy to lower frequency energy is temperature dependent, allowing an accurate method for measuring temperature along the length of the cable. Figure 1 provides an illustration of DTS technology. The DTS technology represents an advanced approach for localizing significant sources of I/I, which can lead to cost-optimized spending on rehabilitation programs. As the DTS method will identify temperature gradients in the sewers, it highlights where infiltrated rainwater is influencing the wastewater being carried to the downstream treatment plant. Figure 2 shows a simplified approach for setting up DTS to study I/I sources in sanitary sewers and is representative of the approach used in this study. Figure 3 is a photograph of the equipment installation manhole (MH).
Project Setting
The District established a regional Private Property Infiltration and Inflow (PPII) Reduction Program in 2011 after experiencing major rainstorms that caused massive sewer overflows and thousands of sewer backups. The District PPII program provides funding to every municipality served by the regional system, and funds can be used for a wide variety of I/I reduction activities so long as the funds are exclusively used for private property measures. The City of Wauwatosa is one such community in Wisconsin with many homes that have connected foundation drains. As a result, the City experiences significant I/I and occasionally has sewer backups during large storm events. The City has been working diligently throughout its system to combat I/I, taking full advantage of District PPII Program funds. The City work, however, has largely focused on addressing problems with sewer laterals and not yet tackled connected foundation drains. Eagle Street in the City of Wauwatosa is one such area with connected foundation drains. The City has cured-in-place-pipe (CIPP) lined the sanitary sewers and rehabilitated manholes using City funds and has rehabilitated sewer laterals with CIPP using District PPII funds. Despite the extensive rehabilitation completed to date, significant I/I persists in this area. As a result, the most suspected sources of I/I were the connected foundation drains and the un-lined portions of the lateral under the homes. Previous flow monitoring data collected by the District showed that flow temperatures in this system responded during I/I events in both cold winter and spring conditions as well as warm summer conditions.
Field Deployment
The field test utilized a DTS system capable of measuring the temperature of water at 1 meter intervals in a long reach of sewers; approximately 1,200 meters in total length for this project. During the field monitoring period, data would be collected for 48-hours of dry weather and three separate periods of wet weather data, when the rainfall event total amounted to at least 25.4 millimeters (1.0 inches). Data analysis would include plotting the temperature profile of the monitored sewers and how the profile varied during rainfall events. Additional data analysis would identify specific locations where temperature changes appear to indicate the presence of I/I inflow sources. After the monitoring system was installed, a dry weather period of data was collected to confirm that the system was working correctly. Dry weather system data collection occurred from May 28 to 30, 2020. Three wet weather events were recorded on June 10-11, July 9-10, and July 15-16. Additional events were also monitored in case the total rainfall exceeded 12.7 mm (0.5 inches), but ultimately these events provided insufficient data to analyze.
Analysis
Color-coded temperature plots (waterfall plots) were prepared for each monitored event. Each of these plots show points of interest along the monitored sewer, including the location of manholes, laterals, and the DTS unit. Plots of flow and rainfall are synchronized to, and plotted with, the DTS temperature data. Observations can be made from reviewing these wet weather event data and the distinct temperature changes that coincide with measured rainfall. Consistent behavior at specific locations, across multiple rain events, provides strong evidence that an I/I source is present and deserving of follow-up field investigations. An example plot is shown in Figure 4 during the July 9-10 rainstorm. To estimate flow along the cable, the study utilized a methodology proposed by Beheshti and Saegrov (Water, 2018), in which a temperature and flow mass balance is performed stepwise in a downstream fashion starting at the upstream end of the cable. Figure 5 presents a comparison of one event between temperature based I/I estimates and the I/I model. Figure 6 shows the accumulation of flow along the pipe during the peak of this same event.
Compared to other methods of locating and quantifying I/I source inputs, DTS could be considered expensive unless considering the extent of information this method generates. BC develop an estimated Return on Investment for using the DTS approach to identify actionable I/I sources. The process used for estimating ROI and the outcome will be detailed in the full paper.
Conclusions
This study showed the capabilities of the DTS method for finding potential significant sources of I/I in a sanitary sewer system. The methodologies developed by Beheshti and Saegrov (Water, 2018) for quantifying I/I flow rates based on DTS data were evaluated and show promise, though further studies are needed to better understand the capabilities and limitations of their approach.
The full paper and presentation will provide further details on the complete study.

Distributed Temperature Sensing along a fiber optic cable can be used to identify specific locations of significant I/I sources active during wet weather events. A study performed during several significant summer storm events provided sufficient data for quantifying actual I/I discharges, proving the technology was successful in warm I/I conditions. A process was developed to locate-specific flow inputs during active events, and results were compared across all three monitored events.

SpeakerLukas, Andy

Presentation time

16:25:00

16:40:00

Session time

15:30:00

17:00:00

TopicIntermediate Level, Collection Systems

Author(s)

Lukas, Andy

Author(s)Andy Lukas1; Rebecca Specht2; Bill Wehrley3; Michael Metcalf4; Rhys McDonald4; Matthew Davis4

Author affiliation(s)Brown and Caldwell, Milwaukee, WI1; Milwaukee Metropolitan Sewerage MMSD2; City of Wauwatosa3; Brown and Caldwell4

SourceProceedings of the Water Environment Federation

Document typeConference Paper

PublisherWater Environment Federation

Print publication date Oct 2022

DOI10.2175/193864718825158726

Volume / Issue

Content sourceWEFTEC

Word count17

Richmond's Story of Integrated Planning, Integrated Permitting, and CSO Compliance

Abstract

The City of Richmond, Virginia, has been working on CSO improvements since before the enactment of the Clean Water Act and completed its first CSO Long Term Control Plan (LTCP) four years before US EPA finalized federal CSO policy in 1994. The most recent LTCP was completed in 2002 and included a list of projects that were incorporated in a state special order by consent (consent order). Since that time, the City had been continuing to implement these approved projects, while staying within specified consent order spending guidelines. In anticipation of needing to update the standing LTCP, the City finalized its RVA Clean Water Plan in 2017 (City of Richmond 2017), which provides a comprehensive understanding of the City's watersheds and associated water resources. The Plan identified the goals and objectives and associated metrics that would guide the City moving forward, and in particular identified the need to continue the implementation of Combined Sewer Overflow (CSO) control projects, as the most cost effective method of reducing bacteria in the receiving waters. In 2018, the City worked with the Virginia Department of Environmental Quality (DEQ) to develop a truly integrated discharge permit that included wastewater effluent, combined sewer overflows, and stormwater discharges. The integrated permit provides the City the opportunity to manage their water resources as one and provides the flexibility to implement projects necessary to achieve the goals and metrics identified in the RVA Clean Water Plan. In 2020, the City was swept up in a legislative effort to finalize CSO compliance across the state of Virginia. Ultimately, the City's consent order for CSOs was amended to conform with the new legislative action, that required the City to develop an Interim and Final Plan for CSO compliance with specific deadlines. The projects identified in the Interim CSO Plan, finalized and submitted to the state in June 2021, were focused on the use of real time controls and other methods to optimize the use of the City's existing infrastructure. These projects were found to be an extremely cost-effective method of reducing CSO volume. The Interim Plan has been submitted on schedule, the recommended projects are being implemented, and the Final Plan is under development and due by mid-2024. According to the amended consent order, implementation of the Interim Plan projects must be completed by 2027, and the Final Plan projects must be completed by 2035. Benefits of Presentation The audience will hear a case study of Integrated Planning, Integrated Permitting, water-quality-based CSO compliance planning, use of emerging technology to maximize use of existing infrastructure to cost-effectively control CSOs, and innovative stakeholder involvement throughout a pandemic.

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

SpeakerLukas, Andy

Presentation time

8:30:00

9:00:00

Session time

8:30:00

10:00:00

Session number5

Session locationHuntington Place, Detroit, Michigan

TopicCombined Sewer Overflow, Combined Sewer System

Author(s)