Underground Sewers Research Articles

Study on organic pollution treatment from Van Thanh canal water by vetiver grass model on gravel and sand in water circulation conditions

Most canals in Ho Chi Minh City receive urban wastewater which was led by underground sewers in the untreated cities and causes serious environmental pollution. The main objective of this paper was to investigate the effects of application models of vetiver grass in purifying wastewater in Van Thanh canal water. This model combined many vetiver grass and materials like sand, gravel, and stone to remove pollutants based on sedimentation, filtration, accumulation, and decomposition mechanisms of microorganisms that allow water to flow through the substrate, the system provides good transport of oxygen into the substrate, facilitating nitrification. The research was conducted under hydroponic conditions in three treatments (Treatment1: Gravel treatment, Treatment 2: Sand treatment, and Treatment 3: Combination material (Gravel& Sand). Each treatment was designed (n=2), with dimensions of 0.66 m x 0.46 m x 0.21 m (length, width, height), a layer of material with a thickness of 80 mm. Results showed that the average processing efficiency in the modes was PO43- 91.34%, NH4+ 96.67%, COD above 80% reaching QCVN 08: 2015/BTNMT, Vetiver had a very high capacity to purify wastewater. Result also illustrated that vetiver grass had a very high capacity to purify wastewater in Treatment 3 called the combination material of Gravel& Sand. Applying the CW CSFS system using Vetiver grass was proved for the needs of surface water treatment in Van Thanh canal water with restoring the ability of natural cleaning and restoring greenery in the whereas.

Broaching the brook: Daylighting, community and the ‘stickiness’ of water

Over the last century, under the modern hydraulic model, waterways across the world have been heavily canalized and culverted, driven into underground pipes, drains and sewers. This hydraulic approach has hardwired an isolated water network into the urban fabric, fragmenting erstwhile patterns and dynamics of life, both human and nonhuman. Ecologically, it has been hugely damaging, reducing water quality and biotic diversity, but also socially, disconnecting citizens from the waterways that service and characterize the city. Consequently, since the 1990s, waterway restoration has become widespread as a design solution to degraded rivers and streams, reinstating compromised hydrological, geomorphological and ecological processes. Deculverting or ‘daylighting’, the focus of this paper, is a radical form of restoration, opening up subterranean, culverted waterways often forgotten by communities above ground. Yet, as this paper emphasizes, waterway restoration has tended to privilege ecological over social objectives, while public engagement in project conceptualization has been limited, conducted ‘downstream’ subsequent to planning and design stages. Restoration schemes have therefore tended to reflect the concerns of professionals rather than communities, overlooking their potential for social renewal and change. Drawing on workshop data collected through participatory mapping exercises, this paper explores the case for daylighting a culverted brook in Urmston, Greater Manchester, focusing in particular on the preferences, concerns and knowledge of local residents. The paper compares professional and community perspectives on the preferred scheme design and potential benefits of daylighting, drawing out differences and tensions between them, temporarily ‘unblackboxing’ the brook. It is ventured that daylighting can unleash the social ‘stickiness’ of water, its proclivity to draw and bind together, to revitalize the park, enhancing connection to wildness, attachment to place and sense of community. This is particularly crucial in the face of decreased local authority funding and related crises in park management.

Modelling and design of a drain cleaning robot

Underground sewers collect waste from domestic and industrial buildings. These pipes are designed to carry only liquid and semi-solid wastes such as soap water and human excrement. However due to improper disposal, solid waste materials such as rags, plastic waste, condoms, sanitary napkins, white cement etc. are also found. Since the pipes are not meant to carry these wastes, they cause blockages. Apart from sewer drains housing societies with sewage treatment plants (STPs) also face this problem. Clearing these blocks either require a human worker, which endangers human life due to presence of toxic gases, or a high-pressure water hose cum suction machine which is very expensive. The aim of this paper is to design an automatic robot which will be able to clear blocks quickly at a much lower cost without any threat to human life. The robot will be lowered into the sewer pipes through a manhole. It will propel itself till it reaches the block then clear the block. The robot is tethered by data cable for communication and to prevent it from flowing away. A rope is used to retrieve the robot once the block is cleared.

Geochemical and hydrological study of coastal groundwater discharging to an urban estuary in northern New Jersey

Coastal zones of urban area have been highly impacted by human activities, and urban estuaries suffer from environmental pollution and degradation of coastal ecosystems. In addition to surface runoff, submarine groundwater discharge (SGD) has been recognized as an important pathway for transport of chemicals to the marine environment. In summer 2017 and 2018, groundwater (n = 39) and sediment (n = 13) samples were collected at depths of 20–175 cm from a sandy coastal aquifer in addition to surface water samples (n = 10) along the Newark Bay, a highly urbanized estuary. Aquifer sediments consisted dominantly of medium to coarse sand and were highly permeable, while they were poor in organic matter. Groundwater was fresh to saline and the pH ranged from 6.62 to 8.68, while dissolved oxygen ranged from 1 to 8 mg/L. The urban coastal groundwater contained elevated levels of nitrate, ammonium, and phosphate with maximum concentrations of 37.2, 11.1 and 4.1 mg/L, respectively, which were significantly higher than those in surface water from the Newark Bay by 5- to 64-fold. The elevated N and P in groundwater may perhaps result from anthropogenic sources, such as the leakage of underground sewers. Estimated discharge of N and P from the highly permeable coastal aquifer to the Newark Bay is comparable to the transport of N and P from the Hackensack River into the bay during dry periods. Submarine groundwater discharge of anthropogenic nutrients could be a significant source of nutrients in the Newark Bay, but further study is needed to better understand the human impacts on biogeochemical cycling of nutrients in the urban estuary.

Manuscript: New GHG Methodology to Quantify Sewer Methane

the Intergovernmental Panel on Climate Change (IPCC) has identified that wastewater in closed, underground sewers in the developed world are not a significant methane (CH4) source (IPCC 2006). Other greenhouse gas (GHG) protocols have followed IPCC's lead and have ignored sewer CH4. This simplification has been contradicted by research (Guisasola, 2008; Foley, 2009; Guisasola, 2009; Gutierrez, 2009; van Voorthuizen, 2011; Willis, 2012; and Liu, 2014) where significant CH4 emissions have been repeatedly detected from both pressure mains and gravity sewers. The Water Research Foundation's (WRF, formerly WE&RF and WERF) Conveyance Asset Prediction System (CAPS) project (WERF Project #U5R12) developed a methodology for estimating collection-system methane (CH4) on a sewershed-wide basis. The method uses hydraulic-model output at average flows, actual sewage temperatures and actual flow rates as input. A Knowledge Development Forum (a workshop that is not for CEU credit) entitled “Sewer-Methane GHG-Methodology Standardization” will be held on Saturday at WEFTEC-2018 in New Orleans. The forum objective is to drive toward WEF-industry consensus on a new greenhouse gas (GHG) accounting methodology for adoption by ICLEI, the California Air Resource Board (CARB), IPCC, and other protocols. This paper summarizes the method and provides specific guidance on its use for estimating sewer-CH4 generation.

Experimental Study on Risks for Underground Hollows Occurrence and Ground Surface Collapses Due to Underground Sewers

Experimental Study on Risks for Underground Hollows Occurrence and Ground Surface Collapses Due to Underground Sewers

Australian-made technology renews Sydney's oldest sewers

Like all large cities around the world, Sydney's major underground sewers are deteriorating through age and reaching the end of their service life. To succeed in its vision to be the lifestream of Sydney for generations to come, Sydney Water's active sewer renewals program needs to renew underground sewers beneath heavily populated and environmentally sensitive areas. One of Sydney Water's pipeline rehabilitation contractors, Interflow, recently applied world class spiral wound lining technology to renew two of these sewers without excavation or interrupting services. This Australian made technology is pushing the boundaries in non-disruptive underground sewer renewal previously considered too difficult or impossible. The projects carried out for Sydney Water and discussed in this paper have twice received the International Society for Trenchless Technology's award for international project of the year.

Jump-Starting Urban Rat Research: Conspecific Pheromones Recruit Wild Rats into a Behavioral and Pathogen-Monitoring Assay

Wild rats, Rattus spp, have adapted so well to urbanization that humans may be obligatory to their survival. Consequently, rats foul human food sources, predate threatened fauna and serve as reservoirs for disease, costing the US economy $19 billion in losses year -1. Urban rat ecology however, remains vastly unexplored because these animals are cryptic, crepuscular, difficult to identify, and hazardous to handle. Additionally, the high-rise buildings that block satellite link-ups, underground sewers and subway tunnels, and rebar enforced concrete covered landscape make it difficult—if not impossible— to track urban animals using traditional radio telemetry. Consequently, there are few ecological studies with free-ranging urban rats. Therefore, we set out to monitor the behaviors and health of free-ranging rats in metropolitan New York. Recognizing that wild rats are attracted to live laboratory-reared conspecifics and that they are sensitive to pheromones, we used soiled rat bedding to repeatedly attract animals to a Remote Frequency Identification (RFID)- based antenna with camera-trap and load cell (scale) for collecting weights. We captured and micro-chipped 13 rats within 50, 30 and 10 m from our antenna and followed their movements. Seven of the 8 animals released within 10 m of the antenna, visited the RFID antenna lure 398 times over 41 standardized days. Males (2.7 visits day-1) visited the antenna at the same frequency as females (2.7 visits day-1; P>0.5), and both sexes spent similar time dwelling at the pheromones (M, 2.9±0.9 sec; F, 2.4.±0.4 sec; P>0.05). The passive integrated transponder (PIT)-tag worked free on the lone individual that did not participate. Within our population, female activity peaked between 6am and 7pm, while males visited throughout the day. Our results demonstrate the potential to safely overcome the primary barriers that have impeded urban rat ecological studies. We used pheromone-based lures to attract micro-chipped rats, irrespective of sex or age-class, where their individual identities, behaviors and pathogen loads could be consistently recorded. We discuss the potential for similar assays to help address several longstanding knowledge gaps in the literature regarding pathogen monitoring over time and space, rat dispersal patterns, population parameters and seasonal migrations through corridors.

Une gestion raisonnée du réseau hydrographique à Saint-Antonin-Noble-Val (Tarn-et-Garonne) aux périodes médiévale et moderne

Rational management of the water system in Saint-Antonin-Noble-Val (Tarn-et-Garonne) in the Middle and Modern Ages. Saint-Antonin-Noble-Val is a monastic town located at the confluence of the Bonnette the Aveyron Rivers which boasts a remarkable network of underground and surface canals based on diversions of the Bonnette River. Originally built by the abbey, it was later widely used and expanded to meet the needs of urban life : cottage industry, driving force, waste water disposal. The use of these underground sewers was taken into account in the design of some houses as early as the XIIIth century. The length of the period of time over which the canals were in use is testimony to the skills involved in building them.

Horror Movies and the Cognitive Ecology of Primary Metaphors

Horror movies consistently reflect metaphorical associations between verticality and affect, as well as between brightness and affect. For example, bad events happen when movie characters are going downwards, or when lights go off. Monsters and villains emerge from below and from the darkness. And protagonists get lost and stuck in dark underground caves, dungeons, tunnels, mines, bunkers or sewers. Even movies that are primarily set above ground or in bright light have the most suspenseful scenes happening beneath the ground and in the dark. An analysis of several horror movies highlights the striking consistency with which the two metaphors “EVIL IS DOWN” and “EVIL IS DARK” are used within this genre. I will argue that these metaphors help in creating fear. Moreover, I will outline how cinematic manifestations of metaphor elaborate and extend metaphorical concepts and ultimately may have a formative role in keeping metaphors alive within a culture.

Recolonisation patterns of benthic invertebrates: a field investigation of restored former sewage channels

Summary The response of benthic invertebrate assemblages to stream restoration is the subject of numerous recent studies, but the process of recolonisation of restored river sections is still poorly understood. Field studies are often flawed by uncertainties about whether the observed species colonised the restored sections after restoration or whether they were present before restoration. We investigated restored streams in the Boye catchment in an urbanised area in Germany. The streams were formerly open sewers and thus were not inhabitable by benthic invertebrates, except for Oligochaeta. Restoration included the construction of underground sewers for wastewater and morphological remodelling of the stream bed. In the spring of 2012, we sampled seven restored former channels connected with near‐natural upstream sections, which were never used as sewage channels and are in good status morphologically, and six unconnected restored former channels. Restoration measures had been conducted between one and 19 years before sampling. Additionally, we sampled 21 near‐natural sites within the catchment and eleven near‐natural sites in neighbouring catchments. Near‐natural sites were considered to be potential source sites from which benthic invertebrates might colonise the restored sites. We recorded 128 taxa and categorised them into five dispersal classes that reflect dispersal capabilities and degree of ecological specialisation. Assemblages at restored sites were characterised by lower numbers of taxa and/or high abundance of hololimnic taxa and poorly dispersing winged species and by higher species numbers and abundance of strongly dispersing generalists. A distinct recolonisation sequence was derived from the observed patterns, in which winged, strongly dispersing generalists colonised most rapidly and were followed by hololimnic species, weakly dispersing generalists and habitat specialists. Restored sites connected with near‐natural upstream sections were colonised more rapidly than unconnected restored sites, particularly by habitat specialists. Almost 90% of the recolonisation events originated from sources within a distance of 5 km. We observed a succession from pioneer assemblages to more mature communities, which resembles that of the surrounding near‐natural sites. In conclusion, assemblages in connected, restored sites needed nine to 19 years to reach maturation, while the settlement of assemblages in unconnected sites is expected to require more time.

Arganzuela Helix Footbridge

The Arganzuela Footbridge is a helicoconical spatial truss consisting of two single-span bodies spanning 117 and 96 m over the Manzanares River and the Arganzuela Park in Madrid, Spain. It connects two residential neighborhoods and provides access to the park for both pedestrians and cyclists.The innovative main structure of both the bodies is a conical spatial steel truss of circular section, with curved diagonals and straight longitudinal chords, all of them inscribed in two tronco-conical surfaces. The diagonals run along four helixes, which may be grouped into two families of contrary directions. The geometrical arrangement thus generated responds to the architect’s aesthetic purpose.This configuration determines the structure of the footbridge bodies that–although have an adequate overall depth in relation to the span and, being a truss, a favorable structural type for a longitudinal structure, lose part of this favorable disposition due to the curving of the diagonals, which introduce undesirable bending stresses in the diagonals.In addition to the unusual shape and dimensions, the foundation is very complex and is greatly conditioned by the existence of underground motorway tunnels and sewers.

Methane Evolution from Wastewater Conveyance

Methane (CH4) production from sewers is a suspected, yet relatively undocumented source of greenhouse gases (GHGs). The Intergovernmental Panel on Climate Change (IPCC) published the 2006 IPCC Guidelines for National Greenhouse Gas Inventories which states that In most developed countries and in high-income urban areas in other countries, sewers are usually closed and underground. Wastewater in closed underground sewers is not believed to be a significant source of CH4. CH4 is a greenhouse gas that has a global warming impact that is 21 times that of carbon dioxide (CO2) and as such is of heightened interest in GHG modeling and inventories. Phase 1 of this project entailed instantaneous methane emissions measurements at 64 raw sewage lift stations throughout the collection system in the DeKalb County, Georgia. During Phase 2 of this project, continuous gaseous- and liquid-phase monitoring were conducted at the discharge of a 16-inch, 3.3-mile-long force main from the Honey Creek Pumping Station. Liquid phase sampling during this phase showed that 8.87 kg of CH4 were emitted per day at the force main receiving manhole during the summer months. The continuous monitoring data was used to calibrate a process model developed by the University of Queensland to predict CH4 and hydrogen sulfide evolution by simulating a force main as a plug-flow, fixed-film reactor. The model was then used to simulate force main CH4 emissions over a calendar year using historical flow and monthly average temperatures. This effort calculated emissions of 52 MT of CO2e/year. Overall this exploratory research project provides following benefits and outcomes. This title belongs to WERF Research Report Series . ISBN: 9781780404691 (eBook)

Results of four years of digital urban monitoring of Rattus norvegicus with RatMap in Hamburg including data on infestation near the surface and in underground sewers

Results of four years of digital urban monitoring of Rattus norvegicus with RatMap in Hamburg including data on infestation near the surface and in underground sewers

Financing the sanitation programme of the Orangi Pilot Project—Research and Training Institute in Pakistan

This paper describes the financing mechanisms for the sanitation programme supported by the Orangi Pilot Project's Research and Training Institute (OPP—RTI) in informal settlements in Karachi and other urban centres in Pakistan. These centre on OPP—RTI support for the inhabitants of a lane to plan, implement and finance the “internal components” — sanitary latrines in the houses, underground sewers in the lanes and neighbourhood collector sewers — and support for local governments to finance the larger “external” trunk sewers into which the neighbourhood sewers feed and also treatment plants. The inhabitants have to raise all the funding to cover the costs of the internal components and in around 300 locations in Pakistan, communities have financed, managed and built their own internal sanitation systems. Local governments can also afford to install the external systems as they no longer have to fund the internal components, and as OPP—RTI has helped them develop much lower-cost methods for planning and building trunk sewers.

How to See the Unseen City

This paper presents different methods and equipments used on how to inspect underground infrastructures, networks, sewers, and pipes in some cities around the world. In New York, underground pipes are inspected using an electronic listening equipment as its first line of defense. Maintenance workers dangle a microphone down a manhole and attach it to a water main to assess whether flow has been disturbed by a leak. More detailed checks are conducted from within a pipe, using what is essentially a video camera on wheels. In pipeline lingo, such tools are quirkily known as smart pigs. In addition to capturing a digital video, a pig can perform radar and sonar scans above and below a water line, searching for indentations and holes in the walls as it rolls down in a pipe. It records its locations with odometer wheels and may be equipped with magnetic sensors to check for aberrations in metal pipes. On the other hand, Japan is the exception on the geospatial-information services front, with a national mapping repository known as ROADIC. This underground mapping system consists of utility grids layered over a road map that utilities and builders consult before breaking ground.

The Arch: Born in the Sewer, Raised to the Heavens

The great ancient civilizations all knew about the arch yet the Greeks relegated its use to underground sewers and never raised an arch above ground: Why? The Egyptians, the Babylonians, the Assyrians and of course the Romans all exploited the arch as a means of spanning and enclosing space. Yet, curiously, Greece, one of the most cultured of the ancient civilizations and the builder of magnificent temples used stone in a most unnatural way, as a beam. The arch as a construction technique is intimately connected to the material of which it is constructed, namely masonry. Stone, when used as a beam is limited by size, scale and proportion. The Greeks certainly understood this as they closely spaced columns to support stone lintels. They also meekly tried to use stone in an A-frame configuration using a corbelled arch in Mycenea (1325 BC) but they never made the transition to the true arch using stone voussoirs. WHY? Perhaps the answer lies in a lack of understanding of the mechanics of the materials and the nature of compression and tension.

Deployment of Fiber Optic Networks through Underground Sewers in North America

The demand for broadband communications is exploding in North America. Two decades of cable laying has resulted in a national backbone of high-speed data network. However, a gap remains; a gap between the metropolitan area network and the prospective customer or building area network. This gap—the last mile—drives much of the fiber optic construction activity today, as broadband providers rush to provide fiber connections to millions of businesses and homes. The traditional way of accomplishing fiber-to-the-home or fiber-to-the-premises is to cut trenches into and under streets to install conduits, splice vaults, and build entrance facilities. The aftermath of this unbridled trenching has left many streets in the urban areas a collage of patches, crumbling asphalt; ultimately affecting the taxpayers who are left footing the cost of rebuilding and resurfacing. Over the past five years, dozens of towns and cities in North America have participated in this experiment of deploying fiber optic cables through u...

Change of groundwater chemistry from 1896 to present in the Mid-Levels area, Hong Kong

In this study, groundwater quality information collected in 1896 (well waters), 1980/1981 (piezometric and seepage samples) and 2002/2003 (seepage samples) in the regions centered by the Mid-Levels area, Hong Kong Island, was compared to illustrate how groundwater quality has changed over a century and the processes controlling it. As shown by saline ammonia and nitrate levels in the late nineteenth century, groundwater was severely polluted by widespread and obvious leakage from poorly designed wastewater collection systems, although groundwater was still a drinking water source for local residents. The extremely high residual chlorines in groundwater demonstrated that large doses of disinfection agents were added to wells at that time. In view of the decline in saline ammonia and nitrate levels, groundwater became less organically polluted in the 1980s probably due to significant improvement of the design of underground sewers. However, more leakage from sources such as salty flushing water and fresh water pipes emerged in the past few decades which added complexity to groundwater chemical systems. Some chemicals were used to identify possible locations of leakages. The temporal variations of the distribution of these chemicals over the area may shed light on the rate of leakage. Leakage from service pipes seems to have improved from the early 1980s to 2002/2003. However, the area is still suffering from widespread and small-scale leakage from service pipes. More efforts should be paid to control small leakages in the future. The findings will be instructive to various government organizations such as the Water Supplies Department and Drainage Services Department to identify possible locations of unobvious leakages in the area.

Plant Monitoring and Control Systems: Making the Case and Managing the Implementation

Severn Trent Water provides vital water services to a population of over 8 million people in over 20 thousand square kilometres in the centre of England. Severn Trent Water own and operate of the order of 640 service reservoirs, 1000 sewage works, 2,200 Sewage Pumping Stations, 25 surface water treatment works, 670 water supply booster stations, 175 Groundwater Sources and over 90 thousand kilometres of underground mains and sewers. A Study was made of the plant monitoring and control issues which resulted in a business case for a telemetry system to provide remote monitoring and control of 3650 installations. The Paper describes the business case methodology and the project management techniques used to define, design and implement the system.