Pope, Richard

A registered Professional Engineer and Board Certified Environmental Engineer, Dick Pope provides corporate-wide odor services work for Hazen and...

Titles from this speaker

Collection System Slopes Lead to Upset Neighbors

Abstract

For years odor assessment and installed odor control technologies centered on wastewater treatment plants because that is where neighborhood complaints originated and focused. Collection systems odors were not very well understood since they suffered from being out of sight and out of mind, essentially underground mysteries, and were generally ignored. With the more recent emerging concern over asset management these underground assets have become a more integral part of the wastewater management process, and the condition of those assets has become a critical question that for so many years had gone unanswered. What was discovered was an underground network of neglected sewer pipes, manholes, lift stations, pump stations, diversion structures, surcharged pipes, inverted siphons, etc., that transported the wastewater of the communities through a network of pipes that supported the formation of nuisance odors that were also corrosive to the infrastructure. These systems may have been designed to endure for 50 to 75 or more years of service, but not all systems survive their design life cycle. Some are older, some are younger but their condition (level of corrosion) varies significantly, and is primarily based on the characteristics of the wastewater, the water age (Time it remains in the system between the home/source and the water resource recovery facility.), the materials of construction and the physical layout of the pipe network. Regarding that physical layout, it is not clear that engineers have always anticipated the ramifications of their designs and how the physical layout of the sewer pipe network can exacerbate both odor formation and release. That odor release encompasses stripping from the wastewater into the headspace of the sewer, as well as escaping the confines of the sewer headspace into the ambient atmosphere where it can impact communities, properties and homes. This presentation focuses on a typical physical sewer layout that has been designed by engineers for years and is common to many collection systems: the intersection where a steep slope meets a much flatter slope. This physical layout condition occur quite often, particularly at the discharge end of a force main where it breaks to a gravity line. Our discussion is not intended to direct engineers to avoid these situations, that is likely impossible given local topography issues, but to recognize these transition zones for what they are, understand how the wastewater and airspace within the sewer will react and protect against their potential impacts. A few of the key issues with the transition zone where steep and flat slopes intersect include: - Steep slope sections of pipe create a negative air pressure along that line as the wastewater drags the headspace air with it as it accelerates downward. That vacuum can create a positive impact as it draws outside air into the system to replace the air it is dragging downstream. It can create a negative impact if the vacuum is strong enough to drain the water out of lateral and house traps that are in place to keep sewer gases out of upstream lines/homes. - Hydraulic jumps occur at the transition zone, which means an area of high turbulence. Turbulence is directly related to stripping odors from the wastewater. - The intersection of fast-moving water meeting slow moving water also creates a positive air pressure shock wave that radiates out and away in both directions from the transition zone. These are real problems facing many communities across the country. Four different case histories will chronicle the impact that this physical layout, intersecting steep and flat slope sewer pipes, had on the surrounding communities and the steps that were taken to address it. The four case histories represent: - California & creating problems for a downtown community - New York & the intersecting steep and flat slope sewer was followed and aggravated by an inverted siphon - Kentucky & a simple solution saved a lot of money - Kentucky & house traps were emptied, and odors were found in the homes. A background will be presented along with the approach taken and the solutions implemented for each of these case histories. In the bigger picture, can case histories like these guide the engineers to design sewer layouts that anticipate potential odor and infrastructure corrosion conditions and include ways to address them.

This paper was presented at the WEF/WEAT Collection Systems and Stormwater Conference, July 15-18, 2025.

Presentation time

11:15:00

11:45:00

Session time

10:45:00

11:45:00

SessionStrategies for Odor and Corrosion Control

Session number03

Session locationGeorge R. Brown Convention Center, Houston, Texas, USA

TopicCollection Systems, Odor and Corrosion Control, Odor/Air Emissions

Author(s)

Pope, Richard

Author(s)R. Pope1

Author affiliation(s)Hazen and Sawyer, 1

SourceProceedings of the Water Environment Federation

Document typeConference Paper

PublisherWater Environment Federation

Print publication date Jul 2025

DOI10.2175/193864718825159876

Volume / Issue

Content sourceCollection Systems and Stormwater Conference

Word count8

Odor Control Begins and Ends with the Community

Abstract

Introduction The natural response by an owner to a community alarmed about nuisance odors from the collection system or water reclamation facility nearby is to investigate where the odors are originating and mitigate them with the implementation of a cost-effective odor control technology that will return the owner back to the ranks of being a 'Good Neighbor'. The owners are finally getting it, the community will not go away quietly, and that effective odor control is required to address the prime driving force & the community. But just as important as installing the right odor control technology may be in appeasing the community, so is communicating with the residents of the community to: - listen to their voices - understand their concerns - ask for their assistance - find out where, when, how strong, and how long the odors last - let them know the steps that are being taken to mitigate the odors - let them know of the time it will take to implement. Simply put, what you don't tell the community, they won't know! And under that scenario the rumors about doing nothing will proliferate and the owner will likely suffer from the loss of credibility. Methodology It is up to the owner then to take the steps necessary to ensure that the loss of credibility is not permanent. Accordingly, creating a dialogue with the community is a critical first step that will go a long way to have them starting to think that you are listening, you do care and that you are doing something to mitigate the bothersome nuisance odors in their community. The steps taken will determine how the community responds, but the necessary steps can vary from simple baby steps to more sophisticated and involved giant steps. Credibility can be regained! Nevertheless, do not expect the community to jump on your band wagon. Understand that the community will always tend to be skeptical of what you do, will want you to do more than is required by regulation, and will demand that you avoid any backsliding. However, after you create that dialogue they will be more likely to stop outwardly fighting the owner at every turn and perhaps even support your efforts. Be prepared, the road may be long and difficult but the benefits will be worth the journey. This presentation will discuss varied approaches that different owners have taken to open up a dialogue with residents through a community outreach program. Some of the varied approaches include, but are not limited to: - Developing bill folds, brochures and/or newsletters - Identifying key community representatives and meeting with them - Conducting informal informational meetings with the residents - Conducting site tours - Creating a Citizens Advisory Committee - Training community representatives to be the 'noses' in the community - Provide monthly updates - Establishing a formal odor complaint hotline with Odor Log Form Phone number Internet site - Oversight Committee - Visitors Center. With the help of technology, the ability to communicate, particularly with the younger generation, has vastly improved the owners resources to communicate with the community, including avenues to reach out and to receive comment back from the community through the internet using: e-mail, Facebook, Twitter, Instagram, etc. The means to communicate with the community has expanded and also made it easier. But as always, controlling the message and reporting the relevant information is still the key aspect of communicating through any media. Careful and planned messages are important. Examples There are many community outreach approaches that are available, from simple to more complex. The utility must select the approach that fits best and move forward with its implementation. An examination of approaches outlined above applied by owners across the country will be presented.

This paper was presented at the WEF/WEAT Collection Systems and Stormwater Conference, July 15-18, 2025.

Presentation time

09:30:00

10:00:00

Session time

08:30:00

11:45:00

SessionEngaging Communities for Smarter Water Management

Session number11

Session locationGeorge R. Brown Convention Center, Houston, Texas, USA

TopicCommunity Engagement, Odor/Air Emissions, Public Education/Information/Communication

Author(s)

Pope, Richard

Author(s)R. Pope1

Author affiliation(s)Hazen and Sawyer, 1

SourceProceedings of the Water Environment Federation

Document typeConference Paper

PublisherWater Environment Federation

Print publication date Jul 2025

DOI10.2175/193864718825159875

Volume / Issue

Content sourceCollection Systems and Stormwater Conference

Word count9

Steep Slopes, Odors, and Corrosion Flow Together

Abstract

Steep Slopes, Odors and Corrosion Flow Together Richard J. Pope, P.E., BCEE Vice President - Hazen and Sawyer For over 100+ years sewer designs have maximized gravity in pipes/conduits to convey wastewater to the treatment facility. Unfortunately, land contours and obstructions require that pumps be used to lift and/or convey the wastewater vertically through force mains to reach a point where the wastewater can again run by gravity. This process is repeated as many times as it takes until reaching the treatment facility. The point where the force main ends and the wastewater flow turns back to gravity is commonly at a high point in relationship to the surrounding landscape to again take advantage of gravity. Sometimes the slope of this force main discharge is steep enough to create a negative air pressure in the pipe headspace, as the drag from the downward movement of the wastewater sucks air in. In many cases this force main discharge connects with another downstream sewer/interceptor line that has a flatter slope. The pipe intersection of a steep slope with a flatter slope, is known to create a hydraulic jump as the faster moving wastewater from the steeper slope pipe tries to overrun the slower moving wastewater. This causes a 'jump like' action in the flatter slope pipe. These features associated with force mains have been recognized and understood since the initial designs of collection systems. But it has taken decades for the engineering community to observe and understand the odor release and corrosion potential of these features. For too long our sewers have suffered from being out of sight and out of mind, and generally ignored. The recent heightened focus on wastewater facility and collection system asset condition and management, helped to open our collective industry eyes on the potentially devastating impact that these features can impart. Regarding these physical layout features, it is not clear that engineers have always anticipated the ramifications of their designs and how the physical layout of the sewer pipe network can exacerbate both odor formation and release. Odor release encompasses stripping from the wastewater into the headspace of the sewer where it travels through laterals and house connections, as well as escaping the confines of the sewer headspace into the ambient atmosphere where it can impact communities, properties and homes. This paper focuses on a typical physical sewer layout that has been designed by engineers for years and is common to many collection systems: the fast-moving wastewater flow of a steep slope pipe and the intersection where it meets a flatter slope pipe. These physical layout features occur quite often, particularly at the discharge end of a force main where it breaks to a gravity line. Our discussion is not intended to direct engineers to avoid these situations, that is likely impossible given local topography issues, but to recognize these transition zones for what they are, understand how the wastewater and airspace within the sewer will react and protect against their potential impacts. A few of the key issues with the steep slope and transition zone where steep and flat slopes intersect include: Steep slope sections of pipe create a negative air pressure along that line as the wastewater drags the headspace air with it as it accelerates downward. That vacuum can create a positive impact as it draws outside air into the system to replace the air it is dragging downstream. It can create a negative impact if the vacuum is strong enough to drain the water out of lateral and house traps that are in place to keep sewer gases out of upstream lines/homes. Hydraulic jumps occur at the transition zone, which means an area of high turbulence. Turbulence is directly related to stripping odors from the wastewater. The intersection of fast-moving water meeting slow moving water also creates a positive air pressure shock wave that radiates out and away in both directions from the transition zone. These are real problems facing many communities across the country. Four different case histories will chronicle the impact that these physical layout features, steep slope and intersecting steep and flat slope sewer pipes, had on the surrounding communities and the steps that were taken to address it. The four case histories represent: California creating nuisance odor problems for a downtown community New York intersecting steep and flat slope sewer odor release was followed and aggravated by an inverted siphon Kentucky a simple solution to odors released from intersecting steep and flat sewers saved a lot of money, capital and operating Kentucky house traps connected to a steep slope sewer were emptied, and odors were found in the homes. A background will be presented along with the approach taken and the solutions implemented for each of these case histories. In the bigger picture, practical examples like these should remind engineers that their designs need to consider the potential odor and infrastructure corrosion conditions that they may cause and include ways to address them.

The following conference paper was presented at Odors and Air Pollutants 2021: A Virtual Event, April 20-22, 2021.

SpeakerPope, Richard

Presentation time

13:20:00

13:40:00

Session time

13:00:00

14:30:00

SessionManaging the Unseen Underground Crisis

Session number2

Session locationLive

TopicCollection Systems, Community, Odor mitigation, sewer pressurization, hydrogen sulfide, proactive approach