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2007 Annual Conference Proceedings

Papers Presented at NOWRA's 16th Annual Technical Education Conference and International Program
Baltimore Maryland
March 12-14, 2007




An Innovative Wastewater Treatment Approach for Commercial and Community Applications
Presenter: Michel Boivin
Co-Authors: Roger Lacasse and Marie-Christine Bélanger

Needs for high quality treated effluent based on simple and reliable decentralized technologies are increasing in sensitive areas, and nitrogen and/or fecal coliform reductions are being required more often. Short and middle-term (3 to 36 months) monitoring results are presented for four real-scale installation based on two different approaches: use of a filtering media made of alternating peat and textile layers as the main treatment unit and use of a combination of this same media as a polishing unit following a trickling filter secondary treatment system. Results are presented for a four bedroom house (sewage flow ∼ 1 m³/d), a bench test unit continuously fed to a daily flow corresponding to a four bedroom house, a restaurant (sewage flow 15 m³/d) and a housing subdivision (sewage flow 12 m³/d). All systems offer good removal performances in terms of BOD5 (< 5 to 10 mg/L, removal ≥ 98%), TSS (< 5 to 10 mg/L, removal > 95%) and fecal coliforms (2.0 log removal). The textile-peat media also reduces in both cases total nitrogen concentrations up to 63% on an annual basis (60-70% reduction during warm weather; 50-60% in cold conditions). Both approaches represent a reliable, high-quality treatment solution at a reasonable cost.
Keywords: Decentralized, Treatment, Sewage, Nitrogen, Fecal coliforms, Sensitive areas.

 

Overcoming Tough Site Conditions at Table Rock Lake Using Drip Dispersal in Imported Soil
Presenter: David Casaletto
Co-Authors: Tom Wallace and Randy Miles

Stone County, located in the Ozarks of southwestern Missouri, is home to a significant portion of Table Rock Lake. The lake, which is widely considered to have the best water quality of any in Missouri is responsible for millions of dollars pumped into the local economy annually from tourism. During the 1990’s, local residents, concerned by diminishing lake clarity and explosive population growth, formed Table Rock Lake Water Quality, Inc. (TRLWQ) to address the declining water quality. Failing septic systems are a significant threat to the lake. TRLWQ sponsored a study in 2001 that suggested septic discharges were entering the lake. The Table Rock Lake area, as well as much of the Ozarks is characterized by steep slopes, fractured limestone and thin soils. Thus, septic tank effluent receives little if any treatment from the natural environment, and contributes to the pollution to the lake. This paper summarizes results the Table Rock Lake National Demonstration Project’s use of drip dispersal of treated effluent to overcome tough site conditions. Examples of the design and installation of a number of advanced treatment systems in challenging site characteristics utilizing drip dispersal in imported soil will be discussed. The project also developed an innovative monitoring method to collect water samples after it has traveled through the soil. The results of this monitoring will
also be discussed.

 

Application of the Marshland Upwelling System for Coastal Dwelling Wastewater Treatment
Presenter: Kelly A. Rusch
Co-Authors: Haibo Cao, Lorna Putnam, and Robert Gambrell

A three-year study was performed on a Marshland Upwelling System (MUS) installed on a coastal camp to investigate the system as a total wastewater treatment technology. The MUS consists of a collection/distribution tank, pump, timer, injection and monitoring wells and the subsurface sediments. Wastewater (gray and black) from the coastal dwelling (permanent residence) was gravity-fed to the collection/distribution tank and intermittently pumped to the subsurface sediments (at a depth of 4.3 m). Four flow rate/frequency combinations were implemented to determine the optimal injection regime. The native groundwater salinity at the field site (Bayou Segnette, Louisiana) ranged from 0-1 parts per thousand near the surface to 13 parts per thousand at a depth of 6 m. Samples were collected twice a month during the summer and once per month during the colder months and analyzed for 5-day carbonaceous biochemical oxygen demand, total kjeldahl nitrogen, ammonia nitrogen, nitrite nitrogen, nitrate nitrogen, reactive phosphorus, total phosphorus, fecal coliforms and E. coli. In-situ parameters (i.e., temperature, salinity, pH and redox) were also recorded. Removal rate constants as a function of vector distance from the point of injection were calculated for each parameter. To date, 295,184 L of wastewater (settleable solids removed) has been injected. The MUS is quite efficient at reducing organic matter, bacteria and nutrients, with the majority of percent removal efficiencies greater than 98%. In three years of operation, the system had not shown any signs of clogging. The MUS is a technology that can be used for total wastewater treatment of coastal dwellings located in areas which preclude the use of septic systems.

 

Using Natural Media Filters in Distributed Wastewater System Serving an EcoTourism-Oriented Development
Presenter: Kevin Sherman
Ecotourism developments are becoming popular worldwide. The term is being used by those who may not fully understand its implications, yet still wish to exploit the concept’s popularity. One of the ways an ecotourism operator’s true intent is revealed is through their choice of wastewater treatment. A historically important and ecologically unique island is being developed in Northwest Florida using ecotourism principles. Distributed wastewater clusters are being installed with fixed film treatment and drip irrigation. Central to these decisions was the preservation of the numerous palm trees found throughout the island. A pretreatment system using the recycled husks of coconuts was chosen to treat wastewater from 26 single-family cottages, a restaurant, and bar. This paper provides information on the design concept and treatment train of this fixed film treatment system. The paper concludes with an update of the longevity of media from the longest continually operating coir fiber system in the United States.
KEYWORDS. Attached growth, Coir, Ecotourism, Fixed Film Treatment, Onsite wastewater

 




Smart Sewers for Smart Growth
Presenter: David Linahan and Maura Cirilli
Smart growth is development that has a positive impact on the economy, the community, and the environment. This unique concept promotes town-centered neighborhoods with a mix of higher density housing, commercial, and retail uses. According to the U.S. Environmental Protection Agency (2006), “Smart growth balances the development and environmental protection accommodating growth while preserving open spaces and critical habitat, reusing land, and protecting water supplies and air quality.” A critical point that is often ignored when community wastewater systems are being designed is the type of sewer system that will be used to convey the wastewater to the treatment system. Numerous factors help decide which option is best appropriate for a given community. A conventional gravity sewer system and a centralized wastewater treatment plant may be considered in a high-populated, urban area. Traditionally, sewers were often planned to extend along drainage ways and streams. They were sized to serve all the homes and businesses with a common regional sewage treatment facility. In less populated areas, where lot sizes are larger and spaced widely apart, a conventional onsite system could be recommended which includes a septic tank and a drainfield. It is common for communities to use a combination of different onsite systems depending upon the situation. There are circumstances that may not be suitable for the conventional gravity sewer system and therefore, an alternative sewer system should be considered.

 

Comprehensive Water Resources Planning for Communities
Presenter: Brent L. Reagor
Co-Author: Robert J, Rafferty, PE

Distributed wastewater infrastructures have a broad definition. These systems and their individual components are influenced by a number of local variables, both technical and nontechnical in nature. Due to the variable nature of distributed infrastructures, the development of comprehensive management schemes can present certain inherent challenges. While a common framework can be followed for planning and implementation of management systems; local environmental conditions, stakeholder goals, and other pressures will ultimately drive the overall processes. The Town of Acton, Massachusetts recently completed a Comprehensive Water Resources Management Plan to address oversight of its existing and future distributed wastewater infrastructure, which includes: 12% of the community served by centralized sewers; 18% of the community served by cluster systems; and 70% of the community served by onsite wastewater systems. The goal of the plan, which was achieved through significant stakeholder involvement, was to create a framework for sustainable water resources management throughout the next twenty years.

 

Ridges of Rice Lake: A Decentralized Wastewater System from Concept, though Design, Construction and Operation and Maintenance
Presenter: Mike Brandt
Ridges of Rice Lake is a 70 home cluster style development located on 275 acres in the City of Elk River, MN. The developer for the project wanted this development to be an upscale home development, and did not want the wastewater treatment system to be a focal point of the project. The focus of the development was to protect the diverse topographical and woodlands along the shore of Rice Lake that borders the development to the north. Several acres of low land separate the upland from Rice Lake, and by clustering the development these areas could be preserved. This development is located outside of the municipal service district, so onsite wastewater treatment systems needed to be utilized for these homes. The developer had completed two previous developments using community wastewater treatment facilities, and thought they knew what type of treatment system was needed for this development. This knowledge brought some interesting discussions and challenges throughout the design process. These issues will be discussed in detail to show the importance of having the soils testing and reporting completed early on in the planning and design process. Other points of discussion will emphasize the importance researching the various technologies and allowing the developer to be part of the treatment process selection. The other aspect of the Decentralized Wastewater Treatment system that will be looked into is what happens to the system after it is installed and operating. Most designers think their job is done once the start up of the system is completed, we will discuss issues that arose on the Ridges of Rice Lake system over the first five years of operations. Specific topics that are discussed in detail are the importance of having a qualified operator to run and maintain the system, and the importance of the designer to have discussions with the developer on setting up the homeowner’s association documents for the development.

 




From Theory to Practice: Applying the USEPA Management Guidelines—The Challenge of Managing and Maintaining 30,000 Onsite Systems in North America
Presenter: Marie Bélanger
Co-Authors: Andy McKinlay and Nicolas Robitaille

The performance of onsite wastewater treatment systems has historically been a national issue of great concern. Decentralized systems are used in about 25 % of the homes in North America and more than 30 % of new development. More and more onsite wastewater systems are an integral part of permanent components of the nation’s wastewater infrastructures. Unfortunately, many of the systems in use are improperly managed and do not provide the level of treatment necessary to adequately protect public health and surface and groundwater quality (EPA, 2003). While it is widely accepted that improperly managed systems contribute to water quality problems, solving the problems through onsite system management can seem an almost impossible challenge. Some of the factors that contribute to this perception are the inadequacy of onsite system regulations, the lack of resources, the lack of homeowner awareness, and the accountability of all the involved parties. Few systems receive proper maintenance because homeowners are either unaware of the need for maintenance or find it a distasteful task. On the other hand, most regulatory programs do not hold homeowners, manufacturers, designers, and installers accountable for system performance after installation. Ultimately it is the absence of a comprehensive management program addressing each of these issues that prevents onsite (decentralized) systems from being considered as an effective and reliable wastewater treatment strategy. Convinced of the importance of proper onsite system management for ensuring system performance, sustainability, system cost-effectiveness, and public health and water quality standards, Premier Tech Environment (PTE) has invested since the beginning of the commercialisation of its system (1995) in a maintenance program for each Ecoflo peat biofilter sold. Over more than ten years, this has evolved from a simple O&M contract between the homeowner and the manufacturer into a management program for which Premier Tech Environment acts as the Responsible Management Entity.

 

Ozarks Clean Water Company: The Development of a Not-for-Profit Sewer Company as a Successful Responsible Management Entity (RME)
Presenter: David Casaletto
Co-Author: Rick Helms

In rural areas of southwest Missouri and in regions without municipal wastewater treatment, the responsibility for maintenance and management of decentralized wastewater treatment systems falls on the property owner, the developer or the property owner’s association (POA). Many times, these groups do not handle this task in a way that provides for the protection of the environment. In some counties, the local government has banned cluster systems due to this lack of proper maintenance. In these cases, the only option open to a developer are individual onsite systems with lot sizes of 3 acres or more. In the fast growth areas between Branson and Springfield, MO this means that more and more land is being divided up into 3 acre tracks. Table Rock Lake Water Quality, Inc. applied for and received a $ 2 million cooperative agreement from the EPA to demonstrate management models for the installation and long-term management of advanced, decentralized treatment alternatives. To demonstrate EPA’s Level 5 Management Model of ownership, operation and maintenance of decentralized systems, the demonstration project formed Ozarks Clean Water Company (OCWC), a nonprofit sewer company. But to realistically demonstrate and evaluate the ownership model, OCWC had to be a free standing and ongoing corporation with its own board of directors. This paper will cover the formation of OCWC, the acquisition of customers, both from inside and outside the demonstration project and how OCWC has grown to over 1000 customers in only 2 years. The presentation will include types of systems owned, methods of ownership, fee structure, contracts and legal obstacles that were overcome.
Key Words: On-site Wastewater Treatment, Management Levels, Advanced Treatment

 

Responsible Management of Onsite Wastewater Systems: Making It as Simple as A-B-C
Presenter: Anish R. Jantrania
The onsite wastewater industry offers technologies for treatment of wastewater from any source and land-based dispersal of effluent on any type of soil, site and environmental conditions. Permanent and responsible operation and maintenance of wastewater treatment and effluent dispersal technologies is the key to ensuring long-term sustainable use of onsite systems. This paper presents information on the five management models proposed by the U.S. EPA and presents a concept on how the five models could be simplified into three levels A-B-C and offers suggestions to promote responsible management of existing and new onsite wastewater systems.

 

Business Attributes of Successful Responsible Management Entities
Presenter: Tom Yeager
Co-Authors: Ray Ehrhard and John Murphy

This paper provides a brief overview of a report soon to be published by the Water Environment Research Foundation (WERF). This report was funded by the United States Environmental Protection Agency (USEPA), and managed by the National Rural Electric Cooperative Association (NRECA). Responsible Management Entities (RMEs) can provide a vital role in protecting public health and the environment by providing management services for decentralized wastewater systems. Functioning much like centralized sewer districts, a decentralized RME can have access to the technical expertise to choose appropriate treatment technologies, oversee installation, and ensure ongoing operation and maintenance.

 




The Effect of Different Types of On-site Wastewater Systems on the Emissions of Persistent Organic Pollutants in the City of Venice
Presenter: Giorgio Ferrari
Co-Authors: Elisabetta Tromellini, Sebastiano Carrer, Francesca Croci, and Giovanna Todesco

In the present paper, the efficiency of the different type of individual treatment systems adopted by hotels of the city of Venice has been evaluated, not only in terms of abatement of macroparameters, such as suspended solids and COD, but also in terms of efficiency in reducing the load of Persistent Organic Pollutants (POPs) like polychlorodibenzodioxins (PCDDs), polychlorodibenzofurans (PCDFs) and dioxin-like polychlorobiphenyls (DLPCBs). Samples from the discharges of 12 different hotels with similar range of comfort (from 4 to 5 stars) but different type of wastewater treatments were monthly collected in the period from March 2004 to February 2005. The results of the present work indicate that the most efficient plants in removing the POPs from the discharges are, by far, the MBR plants. In fact, the extremely efficient removal of suspended solids by MBR plants, through the filtration of the activated aerated mixture by ultrafiltration membranes, drastically reduces the release of POPs from hotels and other domestic discharges and, consequently, reduces the contamination by POPs of the Venice lagoon.

 

Case Study of Sanitation and Wastewater Treatment in a National Park: Jiuzhaigou National Park, Sichuan Province, China
Presenter: Linda S. Gaulke
Co-Authors: Xiao Weiyang and Andrew Scanlon

The administration of Jiuzhaigou National Park (JNP) is currently in the process of reevaluating their sanitation and wastewater treatment needs. Although JNP has attempted to implement sound solutions, they have historically experienced a succession of poor engineering decisions and design flaws. This case study presents changes currently being implemented and identifies concerns to help ensure successful operating conditions. It then presents details of the remaining system that JNP has a goal in place to renovate during 2007 and develops criteria to aid JNP in avoiding similar failures when selecting a solution.

 

On-site Treatment of Higher-Load Graywater at Different Loading Rates Using Submerged Membrane Bioreactor
Presenter: Aileen Huelgas
Co-Authors: Masashi Nakajima, Hiroyuki Nagata, and Naoyuki Funamizu

The treatment of kitchen sink wastewater without energy requirement in permeate withdrawal was investigated using submerged membrane bioreactor (subMBR). The effect of organic loading rate (OLR) was determined by monitoring the organic matter removal, nitrogen and phosphorus, and permeate flux decline. Four lab-scale subMBR were operated at HRT of 4.5, 7, 12, and 24 hours  giving a corresponding OLR of 6.9, 4.5, 2.6, and 1.3 kg/m3-day, respectively. The wastewater was obtained at the university’s cafeteria with COD range of 770-2,050 mg/L. Regardless of the high variations in the COD supplied, relatively stable permeates were obtained at OLR of 4.5, 2.6, and 1.3 kg/m3-day with COD < 40 mg/L. HRT of 4.5 hours was too short to degrade the high organic loading supplied to the system resulting to accumulation of organic matter inside the reactor and relatively high COD of permeate ranging from 40-70 mg/L. The accumulated organic matter in the high OLR system was due to the undecomposed matter from the influent, while the ones accumulated in low OLR system were due to the microbial by-products. The amounts of nitrates and phosphates were low at high OLR due to the frequent sludge withdrawal and were high at low OLR since no sludge was withdrawn allowing their released during the decay of microorganisms in the sludge. Severe fouling was observed in the reactor of OLR of 6.9 kg/m3-day, followed by 4.5, 2.6, and 1.3 kg/m3-day, respectively. Furthermore, the treatment of a mixture of kitchen sink wastewater and washing machine wastewater gave a stable permeate at HRT ≥ 8 hours.
Keywords: submerged membrane bioreactor, kitchen sink wastewater, organic loading rate, organic matter, N and P

 

Effectiveness of Jokaso in Treatment of Domestic Wastewater in Japan and USA
Presenter: Toshiro Otowa
Co-Author: Matt Byers

Japan is a densely populated island nation. Its people have many western similarities and habits. Data on raw waste published in the US and Japan reveal those similarities. Due to environmental sensitivity, the nation has employed many measures to manage the onsite situation including a national ‘jokaso’ code that features design, construction, installation, and maintenance standards. Jokaso treatment is common throughout Japan. An extensive monitoring study (n=34,739 sites) revealed a range of performances. No samples were discarded as being ascribed to ‘system abuse’. 85% of all samples were below 30 mg/L BOD 5Day. These data establish a precedent. Grab sampling is effective when enough samples have been grabbed to represent the population being sampled fairly. Thus, a fair sampling of any system type will reveal a range of effectiveness, and thus describe limitations and strengths. USA monitoring also has shown Jokaso treatment to be consistent and effective. Jokaso systems are widely adaptable to the USA onsite landscapes.

 

Improved Septic Tank with Constructed Wetland, A Promising Decentralized Wastewater Treatment Alternative in Vietnam
Presenter: Viet Anh Nguyen
Co-Authors: Nga Thuy Pham, Thang Huu Nguyen, Antoine Morel, and Karin Tonderski

The decentralized wastewater management approach has a true potential in Vietnam, also in urban and peri-urban areas where centralized wastewater collection and treatment systems are often not affordable. In urban areas of Vietnam, the conventional septic tank is the most common on-site wastewater treatment facility. However, the system has a limited treatment performance, and cannot provide the treatment required to reach national effluent standards and to avoid water pollution. This paper presents an innovative way to improve the treatment efficiency of septic tanks. The Improved Septic Tank, also known as Baffled Septic Tank with or without Anaerobic Filter (BAST or BASTAF), developed and studied at the Centre for Environmental Engineering of Towns and Industrial areas (CEETIA), Hanoi University of Civil Engineering, represents a valuable and promising alternative to the conventional septic tank. Results of laboratory- and pilot-scale research on BAST and BASTAF systems show that at a hydraulic retention time (HRT) of 2 days, the BAST(AF) significantly increased the removal efficiencies in terms of BOD, COD and TSS compared with a conventional septic tank without any significant increase in construction expenses. The results indicated that a reactor combining one sedimentation/equalizing chamber followed by two up-flow chambers could efficiently treat domestic toilet wastewater. Average treatment efficiencies of 80–90% in terms of BOD, COD and TSS could be achieved. The addition of an anaerobic filtration chamber filled with charcoal or local-made recycled plastic balls (VABCO-K) could further increase removal efficiencies by 10% and prevent sludge wash out. Despite its virtues, the BAST(AF) system was not able to reach the strict wastewater discharge standards of Vietnam. Therefore a second study was conducted aiming at investigating post-treatment of BAST(AF) effluent with a vertical-flow constructed wetland. The study showed that treatment of BASTAF effluent in 2-stage vertical flow constructed wetland planted with locally available macrophytes, e.g. Typha Orientalis, Phragmites communis, and Dracaena fragrans allowed achievement of level A, Vietnamese standard for wastewater TCVN 5945-2005 in terms of COD, BOD5, TSS, TN, NH4-N and T-P.


 



How Can We Afford Performance?
Presenter: Richard J. Otis
This year is the tenth anniversary of a revolutionary event in our industry’s history! It was ten years ago that the US Environmental Protection Agency acknowledged in its Response to Congress on Use of Decentralized Wastewater Treatment Systems (USEPA, 1997) that onsite wastewater treatment systems (OWTS) are effective options for protecting public health and water quality when they are properly designed, installed, and managed. USEPA further posited that OWTS are, and will continue to be, permanent components of our wastewater infrastructure. Dissemination of this Response bestowed credibility on onsite and cluster systems, which did much to remove the stigma that they have had as only temporary solutions until sewers are available. Yet, all these accomplishments we have made in the last ten years have barely progressed beyond paper and words. Why? Because investments we have made in existing policies, rules, and practices have created inertia that is difficult to overcome. It will take bold leadership and bold initiatives to overcome this established paradigm.

 

Lessons Learned from Charles City County, Virginia, Project
Presenter: Anish Jantrania
Co-Author: Allen L. Knapp

If onsite/decentralized wastewater systems are to be accepted as alternatives to offsite/centralized wastewater systems, the performance expectations of both should be similar and well understood. Wastewater does not know or care whether it is treated by an onsite system or by an offsite system the potential for adverse impacts on public health and environmental quality from untreated or mismanaged wastewater remains the same for both. It is, therefore, essential to define the performance expectations of onsite/decentralized systems that disperse treated wastewater into the subsurface soil environment rather than into surface waters and communicate those expectations to interested and concerned stakeholders. It is equally important in a performance-based regulatory program for onsite/decentralized wastewater systems that there be a monitoring program in place to assure that the expected performance is attained. When a community chooses a decentralized wastewater solution, it must consider the costs of planning, construction, and operation, but it also must consider the long-term costs associated with monitoring. Since most onsite wastewater regulatory programs are in their infancy with respect to performance monitoring, how can a community plan for those costs? Can a community afford water quality monitoring in the traditional sense, or are there other more cost-effective approaches? Charles City County is the first county in Virginia where managed decentralized wastewater systems are operating under a performance-based regulatory concept. A memorandum of agreement between the county and the regulatory agency allows the county to install and operate these systems under management models four and five, outside of traditional regulatory constraints. The U.S. EPA awarded a grant to study the effectiveness of two types of performance monitoring- water quality and process monitoring. Quantitative data have been collected for water quality and process monitoring parameters and the task of data analysis is ongoing. This paper presents several lessons learned from the project which consists of two decentralized wastewater systems serving 15 to 30 homes.

 

The Warren, Vermont, Decentralized Wastewater Management Demonstration Project: Where Are They Now?
Presenter: Mary K. Clark
Co-Author: Amy Macrellis

In 1998, the Town of Warren, Vermont, and the Mad River Valley Planning District were awarded a US EPA special demonstration grant for a decentralized wastewater project to serve the historic Warren village center. The project team made numerous presentations on the progress of the project through the end of the demonstration project in 2004. Now that the decentralized solution is constructed and has been operating for two years, we can assess how well it is working and how much it is costing to operate. This paper discusses final construction, operation and maintenance, monitoring results, permitting issues, and management costs for the following components of the system:
• A large cluster system expanded from 5,000 gallons per day (gpd) to 30,000 gpd;
• A new small community cluster system;
• Several upgraded or replaced individual onsite wastewater treatment systems;
• The Warren Elementary School’s Innovative/Alternative (I/A) system, the first permitted in the state of Vermont, which has been inspected, sampled, and monitored remotely since construction in 2002.
The Town’s current challenge regarding the decentralized solution involves the large cluster system, which is located beneath a recreational field at the Elementary School. This system was permitted for “existing” flows from businesses and residences constructed before 1986. The design flow for the system, including all the “existing” flows, was 30,000 gpd, and the system is currently operating at approximately 13,000 gallons per day. The Town wishes to allow a modest level of new growth in the village, but an amendment to the system’s permit allowing new flows must be obtained before this growth can take place. Although the site contains over 90 feet of unsaturated sandy material, and is over 300 feet from the nearest stream, the hydrogeologic studies conducted to date have not satisfied the stringent permit requirements and new connections to the system are prohibited. Both the analyses conducted and the remaining permit issues will be discussed from a scientific and community planning perspective.

 

Unsewered Communities: Are Alternative Treatment Technologies the Solution?
Presenter: Scott Wallace
Co-Authors: Jaime A. Nivala, Ryand C. Brandt, and Curt J. Sparks

Review of available information in Minnesota, Iowa, and Indiana indicates that these states (and by extension, the rest of the Midwestern region of the U.S.) have approximately 700 unsewered communities per state. These communities tend to be small, poor, and have limited experience in governance (most are unincorporated). Decentralized wastewater technologies are often perceived as the most cost-effective means to deal with the environmental problems arising from straight-pipe discharges. However, the track record of decentralized systems in the state of Minnesota indicates that operation & maintenance is a critical component of effective system performance. At the present time, compliance rates for decentralized systems are significantly lower for public systems vs. privately-owned systems. A number of factors appear to influence compliance rates; the most significant of which is the decision to hire qualified contract operators. Experience to date in Minnesota would indicate that the “build it and walk away” mentality of the construction grants era is unlikely to provide sustainable infrastructure solutions to the remaining unsewered communities in the United States. It is likely that state and federal agencies will have to redefine their mission and focus if the problem of unsewered communities is to be fixed in a cost-effective manner.
Keywords: Unsewered community; straight-pipe; decentralized wastewater; O&M


 

Identifying and Overcoming Barriers to Progressive Policy Making for Large-Scale Rainwater Harvesting
Presenter: Chantelle Leidl
Co-Authors: Dr. Khosrow Farahbakhsh and Christopher Despins

Rainwater harvesting (RWH) is a simple and logical technology that can readily be used for indoor, non-potable applications to supplement municipal water supplies. Its practice is prevalent in isolated, rural pockets across Canada, but growing stress on municipal water systems and increasing individual commitments to environmental sustainability are perpetuating its use in the urban environment as well. However, the widespread adoption of RWH is hindered by the lack of a comprehensive and integrated regulatory structure that enables and empowers all pertinent players. This paper explores why a progressive regulatory framework is required to facilitate RWH and how it could possibly be developed. The current context for Ontario is detailed, highlighting recent initiatives for non-potable water use. Barriers to future progress are discussed and case studies from North America and abroad are given. This research is part of a greater project aiming to build capacity for RWH in Ontario and Canada, currently being advanced at the University of Guelph, Ontario.

 

Large-scale Rainwater Harvesting in Urban Settings—Design, Operation, and Water Quality Considerations
Presenter: Christopher Despins
Co-Authors: Dr. Khosrow Farahbakhsh and Chantelle Leidl

Rainwater harvesting (RWH) is the ancient practice of capturing storm runoff from roofs and storing it for a later purpose. A case study is presented with an emphasis on the design, operation, and water quality aspects of rainwater harvesting system installed in an existing home in an urban setting. The design of a RWH system for a new residential LEED-H ‘Green Home’ is discussed in a supplementary design case study. Data collected from the continuous monitoring of the cistern volume, cistern temperature, site rainfall, pump electricity use, and household rainwater consumption at the retrofit site is also presented. Rainwater samples were collected from seven sites in the Guelph, Ontario region, and were analyzed for pH, turbidity, colour, UV absorbance, total and fecal coliforms, and TOC. Samples were collected from the cistern-stored rainwater and following each site’s post-treatment unit processes. Additional parameters, including Polycyclic Aromatic Hydrocarbons (PAHs), total metals, Campylobacter and Legionella were analyzed by an external testing facility for selected samples. The preliminary results of the monitoring program indicate a contrast between rainwater supply and demand – rainfall events increase the cistern volume at irregular intervals, whereas the nonpotable water demands of the household are relatively constant over time. Also observed was a decrease in temperature of the rainwater stored in the cistern throughout the late fall and early winter months. Rainwater quality analysis shows several important trends: 1)cistern-stored rainwater from a majority of the sites share a neutral pH (5.6-8.9), low turbidity (0.6-1.6 NTU), and moderate colour (12.7-32.3 CU); 2) treatment, regardless of the technique applied, (firstflush device, UV lamp, hot water tank, etc.) reduces the presence of total and fecal coliforms to less than 1 CFU/100 mL.

 

Financial and Technical Constraints of Sustainable Urban Water Reuse
Presenter: John W. Norton
Co-Author: Walter J. Weber

Sustainable urban water systems are those systems which responsibly limit water withdraw and discharge to and from the environment. Two approaches are used to achieve this goal within the water system, water use reduction technologies and internal water reuse. This paper addresses the financial and technical feasibility of urban water reuse schemes which use the system-wide implementation of decentralized treatment technologies. We provide an analysis of the optimal water system design to achieve the joint goals of water quality requirements, cost-effective implementation, and sustainable system operation. This analysis considers the economic tradeoff between economies of scale, piping and pumping costs, and the treatment efficiency of mixed versus targeted wastewater streams. New understanding of the significance of emerging contaminants such as pharmaceuticals and societal resistance to urban water reuse are included as factors in this analysis. We first present an outline of the relevant technical, managerial, and societal issues which impact such an implementation and propose a strategic framework to achieve an optimally designed decentralized urban water system. We describe an ordered series of recommended implementation phases to allow the optimal selection of specific technologies for each of the various sub-systems within the overall urban water super system. We then describe the first such phase, a method of implementing decentralized water treatment units to address water quality degradation within the potable water distribution network, and detail the technical and financial considerations of this stage of the overall water system optimization. Finally, we present a framework for analyzing the cost effective implementation of distributed wastewater treatment technologies to target specific contaminant streams and to provide user-specific levels of recycled water quality.

 

Reclamation and Refuse Projects in Context of an Onsite and Distributed Water Infrastructure
Presenter: Robert Rubin
Co-Authors: Kevin Eberle and Tim Baldwin, P.E.

Historically onsite wastewater recycling efforts have been associated with the use of traditional soil based wastewater systems while municipal wastewater reuse programs have been associated with water management programs in the humid southwest. Weather patterns, development patterns, demands for water and costs associated with development of water resources are forcing communities throughout the nation to examine water reuse as an element of a total water management effort. Today, increasing stringent limits imposed on NPDES permit holders and the stringent demands placed on potential development coupled with improved understanding of water quality requirements associated with agricultural, silvicultural, recreational and industrial uses of reclaimed water force recognition of reuse efforts as a part of total water management efforts incorporating lessons learned from distributed wastewater systems. Increased demands on water resources will encourage more comprehensive approaches to management.

 




ReCip® Water Treatment System with U.V. Disinfection for Decentralized Wastewater Treatment—Part II: Water Quality Dynamics
Presenter: Leslie Behrends
Co-Authors: Laura Houke, Pat Jansen, Keith Rylant, and Catherine Shea

The Tennessee Valley Authority (TVA) has developed a novel wastewater treatment technology, ReCip®, which is currently being used commercially to treat wastewater from single-family households, condominiums, day use facilities, animal feeding operations and at an airport deicing facility. The ReCip® technology is a fixed-film process that alternates between aerobic and anoxic environments. The simplest two-cell system is based on subsurface-flow constructed wetlands technology but with frequent fill and drain operations (6 to 24 times / day), to provide frequent exposure of the microbial biofilms and plant roots to atmospheric oxygen. During the past two years, TVA has collaborated with the American Public Power Association (APPA), to integrate low wattage ultraviolet lamps (U.V.) into the ReCip® system. The new U.V. light configuration, in reciprocating mode, exposes wastewater to low- wattage U.V. lights (65 watts), six to twenty-four times per day. The intermittent exposure of the wastewater to the U.V. lamps has resulted in 2-5 log reductions in wastewater microbial pathogens, such as E. Coli. Furthermore, the U.V. system did not impair wastewater treatment functions. The U.V. ReCip® system produced a treated wastewater that was clear, odor free, with significant removal of indicator pathogens, and with very low levels of suspended solids, COD (90% removal), ammonia-N (99% removal) and total nitrogen (66% removal). In general, the treated wastewater was of a quality that could be reused for flush water, subsurface irrigation, or groundwater recharge.
Key Words: Decentralized, denitrification, disinfection, nitrification, reciprocating wetlands.

 

Sustainable, Low-Maintenance Disinfection for Onsite Systems
Presenter: Roger Lacasse
Co-Author: Denis Pettigrew

As reported in literature, chlorination and UV light are more adapted for disinfection of wastewater in community or municipal installations. For individual wastewater treatment systems, the application of these processes presents some risks for health and safety and the management required to assure safe performance is too costly. In view of these limitations, a need remains for the development of a sustainable and low maintenance disinfection process for onsite systems. In the last four years Premier Tech Environment (PTE) has developed an approach of passive disinfection based on a horizontal sand filter (HSF) fed by biofilter effluent. The HSF system has been tested at full scale in two different sites located in Ontario and Quebec (Canada). After more than 33 months of system operation and 150 sampling days, the effluent treated contains less than 20 counts/100 mL in fecal coliforms. Only 6% of the results exceed the usual criteria for surface discharge of 200 counts/100 mL.

 

Case Study: Treated Wastewater Reused for Toilets at Ontario Truck Stop
Presenter: Heather Millar
Co-Authors: Dave Harsch, Ignatius Ip, and E. Craig Jowett

A truck stop near London, Ontario needed to double the capacity of its facilities. The expansion would increase the design wastewater flow, requiring decommissioning of the existing facultative lagoon and construction of a new wastewater treatment system. Severe space limitations, lack of groundwater supplies, and the concern of nitrogen loading of the groundwater demanded a design with an innovative approach. The solution would be re-use treated sewage immediately in the facility for toilet and urinal flushing, thereby reducing the size of the inground disposal, reducing the demand for potable water, eliminating water shortages, and reducing the nitrogen loading of the groundwater by an estimated 50% over traditional septic systems. The design combines Waterloo Biofilter treatment with secondary polishing and disinfection using an MS Filter. At the time, standardized requirements for reuse of non-potable water did not exist. As such, the Ministry of the Environment (MOE) and the Ministry of Municipal Affairs and Housing would have to collaborate to establish re-use guidelines, including effluent quality objectives and sampling schedules, and plumbing standards for the recycled water distribution system. Since commissioning in January 2004, the reuse system has performed consistently within Certificate of Approval objective levels, the site has not experienced any water shortages, and nitrogen loading has been reduced by 67% over conventional septic systems. The success of the system is due to proper operation and maintenance schedules, as well as co-operation from the owners in terms of minimizing stress on the system by tailoring cleaning and kitchen practices. While reuse was endorsed by the MOE, the imposed sampling schedule is expensive and onerous for the client, with one third of annual operating costs devoted to sampling and chemical analyses. To alleviate the financial burden and to encourage the client to consider reuse at other facilities across Canada, an amendment to the Certificate of Approval is proposed to decrease sampling from weekly to monthly, combined with weekly site visits, photographic records and on-site testing of pH and turbidity as a record of system performance between samples. Operating costs may be reduced further if a higher level of process control logic, feedback and communication between subsystems was incorporated into the system design. The introduction of flow meters and level sensors with feedback as well as a remote monitoring/data logging system may reduce troubleshooting time on-site, protect equipment from being overused and prevent overprocessing and underprocessing of wastewater. The higher level of control would aid the operator in managing the system and optimizing treatment; however, the capital cost associated with the process control equipment must be balanced with the potential savings in operational costs.

 

A Submerged Attached Growth Bioreactor and Membrane Filtration for Water Reuse
Presenter: Philip Pedros
Co-Author: A. McBearty and W. W. Bruce

This paper discusses the integration of a submerged attached growth bioreactor (SAGB) with hollow fiber membrane microfiltration (MF) to meet the reuse requirements for a small decentralized wastewater treatment plant. The use of a SAGB for biological nitrogen removal provides a system with a small footprint due to the ability of the system to operate with high concentrations of biomass. This particular SAGB is constructed in concrete tanks below grade thereby reducing the area of the building required for the ancillary equipment. The biological nutrient removal (BNR) process, upstream of the microfiltration process, produces a high quality feed water to the MF unit. The coupling of a submerged attached growth bioreactor with microfiltration (SAGB/MF) is a technology that has applications where space is limited and stringent effluent limits exist. This technology was applied to the decentralized wastewater treatment plant at the Jefferson at Bellingham, Massachusetts. During the first year and a half of operation, the average effluent total nitrogen concentration was 3.57 mg/l and median fecal coliform was zero.

 

Wastewater Treatment and Recycling in Urban Villages: Implementation and Policy Issues for Western Australia
Presenter: Beth Strang
Co-Authors: Dr. Martin Anda, Dr. Catherine Baudains, and Professor Goen Ho

With a drying climate and increasing urban populations many cities in Australia are facing drinking water shortages. In Perth, the capital of Western Australia (WA), summer water restrictions are common and in the face of declining rainfall the State Government is developing new water strategies. One strategy involves a closer alignment and integration of land use planning with water management. This will require residential land developers to look at the total water cycle and how it fits into local and regional water plans. Another strategy, currently being trialed in WA and the focus of this research, involves the development of wastewater treatment and reuse systems for non-drinking water applications, such as irrigating public open space, in urban villages. By treating and reusing wastewater locally, developers can work with local and regional water planners to help reduce drinking water demand, whilst ensuring environmental flows are maintained. In WA, two residential developments are installing decentralised wastewater, specifically greywater5, treatment and recycling systems; Bridgewater Lifestyle Village (BWLV) in Erskine and Timbers Edge Residential Resort (TimbersEdge) in Dawesville, refer figure 1. Both sites are located in high population growth corridors and environmentally sensitive areas that experience high water tables due to their proximity to the Peel Harvey Estuary. Both sites are currently under construction and represent two different greywater treatment systems and constitute the first trials of decentralised wastewater treatment and recycling within the Perth metropolitan area. BWLV is in the process of installing 380 greywater systems with a central overriding management system, with the treated greywater being used to irrigate the individual residences. Whereas TimbersEdge will have 260 homes connected to one central greywater treatment system, with the treated greywater then used to irrigate public open space within the development. This paper will discuss: the complexities of getting the systems approved, including the legislative and regulatory constraints; the maintenance and monitoring schedules required to meet the environmental and public health issues; discuss the community involvement required to ensure that the systems are accepted and that the residents feel empowered and confident with the systems; and briefly discuss how these issues have led to the development of a new management tool, known as the DeWaTARS framework. The development of the DeWaTARS framework will enable the development and application process of future applications within the Perth metropolitan region.

 

Development and Demonstration of an In-house Water Reclamation and Reuse System for Large Institutions
Presenter: Suresh Surendran
Co-Author: A. D. Wheatley

To achieve sustainable water management, there is a need to consider alternatives, in addition to conventional water supply and wastewater dispersal or flood control systems. Planned direct de-centralised grey and storm water reclamation for non-potable use is now considered as a solution for significantly growing water and wastewater problems in the UK. It could be a sustainable alternative to supplement the main water supplies for non-potable uses and could also reduce wastewater problems such as pollution and flooding. However, in the UK, there are no water quality standards for WC flushing water use, nor design guidelines for greywater reclamation. The aim of this paper is to describe the experience during the design and monitoring of performance of a storm and greywater reclamation system for WC flushing, tested in a university accommodation hall during the 1994-98 period. This paper will also discuss water usage, greywater characteristics, social acceptability, cost, risks and benefits to both the householder and the wider environment. The research reported here was based on a study that developed a novel multi-barrier reclamation system to achieve a sufficient quantity and “bathing quality” water without high maintenance or cost. The performance of this combined greywater and rainwater reclamation plant showed that the plant was always able to meet the UK/EU bathing water standards without coagulants, disinfection or day to day maintenance and with low head loss.

 

Subsurface Wetlands as Effective Wastewater Treatment and Recycling Options in Urban Villages: Western Australia Case Studies
Presenter: Beth Strang
Co-Authors: Dr. Stewart Dallas, Dr. Martin Anda, and Dr. Kuruvilla Mathew

Around the world there is a paradigm shift occurring, one that is moving away from traditional centralised wastewater infrastructure towards decentralised wastewater system options. In Western Australia (WA) the development of decentralised systems has been slow. However significant steps have been made towards making decentralisation a reality, with several innovative technologies based on natural biological processes being trialed, such as constructed wetlands. The WA State Government is investing research in practical case studies that will assess the viability of decentralised wastewater schemes, within WA urban villages. The research is to be conducted over three years starting with two decentralised greywater systems, progressing in the final year (2008) with research into combined wastewater systems. The first case study site, Bridgewater Lifestyle Village (BWLV) located in Erskine south of Perth, will encompass 380 individual greywater systems that are centrally managed with the treated greywater used to irrigate the gardens of each home. The second site, Timbers Edge Residential Resort (TERV) located in Dawesville also south of Perth, will encompass 260 homes connected to one centrally managed greywater treatment system, with the treated greywater being used to irrigate the estates public open space. Both of these sites are located in a high population growth corridor adjacent to the Peel Harvey Estuary; are within close proximity to RAMSAR5 protected wetlands; and experience high water table levels. In order to meet environmental and public health concerns, innovative solutions would be required. Each site employs a wastewater treatment and recycling system that mimics natural processes. This paper will introduce two types of subsurface constructed wetlands that are either operating or will be operating in the near future at the two case study sites. The first system discussed is the evapotranspiration trenches at BWLV. These are a low maintenance biological system consisting of a plastic lined gravel-filled trench planted with various hardy aquatic plants and will be placed in home sites where the groundwater table is higher than 50cm. The second system at TERV is known as the Biofilter system and consists of a series of concrete chambers planted with wetland plants. This paper will then discuss how these systems recycle the water locally to reduce water demand; what the residents’ responsibilities are and how different management arrangements can effectively manage and operate these systems.

 




Analysis of Remote Monitored Water Use Trends and Patterns in a Commercial Facility
Presenter: Clement Solomon
Co-Authors: Joseph Kamalesh and Dr. Alan J. Sexstone

Decentralized or onsite systems are a viable and cost-effective option for domestic wastewater treatment and dispersal when conventional sewers are not feasible. It is estimated that approximately 23% of the 115 million occupied homes in the United States are being served by onsite systems. They can be used to treat and disperse wastewater from single family dwellings, clusters of homes and commercial facilities. Typically, onsite systems for residential applications are designed based on the total number of bedrooms while in the case of commercial applications use a different design methodology. The primary objective of this research study was to obtain real-time monitoring data relating water use and onsite system design standards/specifications for a commercial facility (church). Water consumption was recorded on a continuous basis using a digital magnetic water meter installed on the incoming water supply line. Wastewater from the church was treated by a constructed wetland system originally designed in 2000 for a total of 350 seats. In 2006, the number of actual users on any given Sunday ranged from a 737 to 1,774. Analyses were performed relating water use, number of users, system design specifications and trends in water use. It was observed from this study that the system design based on just the number of users at the facility may not be an accurate reflection of the actual amount of wastewater generated. Data indicated no direct correlation between the numbers of users with actual water use. Despite the five-fold increase in users, 75% of the time peak Sunday loading of the wastewater wetland did not exceed 700 gpd, the original design criteria for a 350 seat facility. We conclude that design criteria currently used to size decentralized onsite wastewater systems for commercial facilities are not sufficiently predictive and should be reconsidered. This research study was conducted by the National Onsite Demonstration Program (NODP) of West Virginia University, and funded by the US Environmental Protection Agency.

 

45 Factors Affecting the Performance of Primary Treatment in Onsite Systems
Presenter: Victor D’Amato
Co-Author: Sarah Liehr

Approximately 23 percent of the estimated 115 million occupied homes in the United States are served by onsite wastewater systems, the vast majority of which include a septic tank, grease trap, or both for primary treatment. These units are efficient, simple, low-energy treatment units whose performance is critically important to the overall functioning of onsite wastewater systems. Regulations, industry standards, guidance materials and engineering texts vary widely and are often incomplete in their consideration of the factors that may influence primary unit performance in onsite systems. The objective of this research was therefore to identify, compile, analyze, and report on the existing body of work addressing the factors impacting the performance of primary treatment units in onsite wastewater systems. Design, construction/installation, and maintenance issues were considered, with a goal of establishing what is known, what is not known and what future research is needed in this area. Over 700 sources of information were collected, with most reviewed and presented in a project report and white paper. A bibliographic database, which can continue to be updated into the future, was developed as a companion piece to the white paper, as a tool for researchers and practitioners. The work was administered by the Water Environment Research Foundation (WERF) and the products may be obtained through WERF at www.werf.org. The reader is directed to the report and white paper for more complete discussion of the information presented in this paper.

 

Field Comparison of Rock-Filled and Chambered Trench Systems
Presenter: Sara Christopherson
Co-Authors: Jessica Wittwer, Tim Haeg, Dan Wheeler

Due to actions of the Minnesota State Legislature, systems utilizing chambers and synthetic drainfield distribution media are allowed to be designed and installed up to 40% smaller than the standard or conventional trench system area, under provisions of a special “Warrantied System” category. If approved for “Warrantied System” sizing, manufacturers can receive reduced sizing guidelines in exchange for offering a five-year performance warranty and technical information. There has been debate among regulators, professionals and manufacturers about the long-term hydraulic longevity of systems that use the reduced-area trenches for final treatment and dispersal. A project was designed to identify whether there is a statistical difference in performance between chambered and rock-filled trench systems. This was achieved by a large-scale survey of over 100 selected onsite systems of both rock-filled trenches and chambered trenches across seven Minnesota counties. Each system type was studied within three major soil permeability categories (fast, medium and slow) utilizing soil texture classes. In addition to a general evaluation of the system and homeowner survey including questions on usage and maintenance frequency, the percentage of the system in use at the time of the site visit was determined. This was possible because a majority of trench systems in Minnesota utilize drop box or sequential distribution which loads the trenches in a particular order so that one trench is loaded to a specific level before the subsequent trenches are utilized. Adjusting both types of systems to a standard size datum, the ponding levels were compared. Surprisingly nearly 60% of the systems visited during the study of the ages 5 -10 years did not have any ponding observed at the end of the first trench segment. When the amount of ponding was compared between rock-filled and chambered systems the data was not able to prove the hypothesis that chambered systems of a similar age as rock-filled systems utilize 25% less area than the rock systems at 10% significance level. To the contrary, the results indicate that rock-filled trench systems were utilizing less soil treatment area than the chambered systems due in part to the smaller area per trench of the chamber systems. More mature trench systems of both types need further investigation and analysis to more fully evaluate this issue.


 



Variability in Denitrification Rates: Literature Review and Analysis
Presenter: Maria B. Tucholke
Co-Authors: John E. McMcray, Geoffrey Thyne, and Reagan Waskom

Extensive denitrification research has been performed over the last 60 years. Denitrification is difficult to measure at the watershed scale; yet denitrification rates at this scale are needed for watershed-scale assessments. Ideally, correlations could be developed to relate denitrification to easily measured variables. However, progress in developing correlations has been limited by the lack of unified measuring methods, in consistency in reported units, and assumed kinetics. Additionally, the current knowledge of sub-surface denitrification is site specific; thus limiting its use for making nitrate (NO3 -) removal predictions on a watershed scale. The objectives of this study were to: (1) perform a rigorous literature review, summarizing denitrification rates from past research; (2) illustrate the range in denitrification rates based on measuring methods; and (3) show the variations in rates due to two important variables (water-filled porosity and organic carbon content). To achieve this objective, denitrification rates and soil characteristics from 601 unique soil experiments from 41 different sources were assimilated and analyzed. While denitrification is known to follow both zero-order and first-order kinetics, only zero-order reaction data were used because the majority of the rates found in the literature were not shown to be a function of NO3 - concentration. Cumulative frequency diagrams (CFD) proved useful for quantifying the variations in denitrification rates. Denitrification rates ranged from not detectable up to 157 kg N ha-1 day-1, with a 50th percentile value of 0.3 kg N ha-1 day-1, and a 90th percentile value of 14.5 kg N ha-1 day-1. Denitrification rates measured in the laboratory were typically much larger than rates measured in situ, possibly due to the higher soil moisture content in laboratory experiments. Although an increase in organic carbon content is assumed to increase denitrification, a correlation could not be established (R2=0.029).


 



Septic Tanks and Drainfields an Engineering Perspective
Presenter: Steve Branz
Septic tanks and drainfields are the two primary components of onsite wastewater systems. The basic knowledge of septic tanks and their function will be reviewed. The aspects of the septic that are unknown will be presented. The annual investment in septic tanks warrants additional research that promotes a better understanding of performance versus investment. What transpires inside the ponded effluent of a drainfield is unknown. Many entities state that a drainfield is only a dispersal mechanism, this is erroneous. A review of basic wastewater treatment principles will be presented. A consensus of serial or parallel drainfields does not exist among the states. A better understanding of the physical, chemical and biological processes that transpire in the ponded effluent of drainfields must be learned before optimum configuration of drainfields can be determined.

 

Speaking the Same Language: An Update on the CIDWT Decentralized Wastewater Glossary Project
Presenter: Nancy Deal
Co-Authors: John Buchanan, Mark Gross, David Gustafson, David Kalen, Justin Mechell,
and Randy Miles

Technical advancement in decentralized wastewater treatment options has been accompanied by statewide, regional and national educational programs that share research, demonstration and manufacturer literature among a broad group of industry professionals. Initiatives aimed at standardizing industry practices are underway as well. Examples include the National Onsite Wastewater Recycling Association (NOWRA) Model Performance Code, the National Precast Concrete Association (NPCA) Best Practices manual and the National Environmental Health Association (NEHA) Certified Installer credential program. The increased interaction between and among these and other groups has created a critical need for common terminology relative to system siting and design, component construction and installation, operation and maintenance as well as regulatory permitting/enforcement and consumer education. That need is being addressed through the Consortium of Institutes for Decentralized Wastewater Treatment (CIDWT) Glossary project. The CIDWT is a non-profit educational organization dedicated to research, teaching, training and outreach education to students and practitioners in the decentralized wastewater field. This effort began as a relatively informal and unfunded endeavor by members of CIDWT who experienced first-hand the challenges that arise as a result of confusing or contradictory vocabulary. The unofficial project evolved into a sanctioned effort thanks to funding from the Environmental Protection Agency (EPA) through the Water Environment Research Foundation (WERF). CIDWT members participating on the Glossary work team are from geographically diverse areas and have familiarity with many different technologies. Their expertise encompasses a wide range of disciplines, including engineering, soil science, operation and maintenance as well as regulatory permitting and enforcement. Many were members of the original group that worked on the unofficial version of the Glossary. All have served as writers and/or reviewers on the CIDWT Practitioner and University Curriculum Development projects and the National O&M Service Provider Program project. The writing team recently completed the initial stage of stakeholder review and revision and has proceeded into phase two of the process.

 

Privatization Case Study: Administration of the State of Massachusetts’ Onsite Wastewater Training and Certification Renewal Program
Presenter: Thomas Groves
New England Interstate Water Pollution Control Commission’s role in training and certification in Massachusetts continues to grow. In addition to running the state’s wastewater treatment plant operator certification and training program, NEIWPCC is now coordinating the Massachusetts Title 5 (state onsite sanitary code) Onsite Wastewater Training, Examination, and Certification of Soil Evaluators and System Inspectors. In April 2004, the Massachusetts Department of Environmental Protection transferred the programs to NEIWPCC, which will conduct the training and exams as well as chair an Onsite Advisory Committee (OAC) that was established to oversee these efforts. NEIWPCC’s assumption of this new role comes amid growing awareness of the importance of onsite training and certification. There are close to 2,000 Soil Evaluators and over 3,500 System Inspectors statewide. Recently approved revisions to Title 5 require certification renewal for all Evaluators and Inspectors certified by the state since the program’s inception in 1995. The renewal program requires all existing Evaluators and Inspectors to renew through NEIWPCC by January 1, 2007; the renewed licenses are good for three years. Prior to the next renewal deadline (January 1, 2010), all licensed Evaluators and Inspectors are required to obtain 10 hours of continuing education training credit. The intent of this program is to insure that practicing onsite professionals are properly trained and are continuing to improve their knowledge of the industry. The renewal program will also include a fee that will be used by NEIWPCC to provide oversight and implementation of the program as well as to subsidize and increase the training opportunities available to these professionals.

 

Southeast Minnesota Wastewater Initiative Post Project Assessment: A Case  Study
Presenter: Doug Malchow
The Southeast Minnesota Wastewater Initiative was a three year Environmental Protection Agency funded project which provided educational, facilitation, and funding assistance to small unsewered communities needing to upgrade their wastewater treatment. A survey of task force members from communities that had made substantial progress toward improved wastewater treatment was conducted. Survey results show that community task force members value ongoing facilitation assistance over educational and financial assistance. This result suggests that communities through task force members or local government staff may not have sufficient time and expertise to dedicate to the often overwhelming number of tasks that need to be completed on an ongoing basis. Wastewater treatment infrastructure funding agencies need to not only allocate funds for design and construction purposes, but provide additional funds to hire an unbiased community wastewater treatment facilitator.


 


 

Numerical Modeling of Flow and Transport Processes in Variably Saturated Porous Media Beneath Subsurface Treated Wastewater Drainfields: Implications for Groundwater Mounding and Nitrate Transport and Fate
Presenter: Brian Davis
Co-Author: Scott Wallace

Numerical models for variably saturated porous media are a powerful tool for investigating the effects of drainfield design on groundwater elevations and nitrate transport and fate. The Hydrus numerical model is a finite element model which solves the Richards equation and advective-dispersive equation for water flow in variably saturated porous media and mass transport and fate, respectively. The Hydrus model was used in this case to investigate these processes beneath and downgradient from a drainfield serving a small town. Model results showed that the hydrogeologic properties of the site soils allowed for minimal water table rise under design conditions. Model results also showed that nitrate transport in the surficial aquifer beneath and downgradient from the drainfield was a function of surficial aquifer thickness and hydraulic natural gradient. In this case study, the model showed that the limited thickness of the surficial aquifer and small natural hydraulic gradient resulted in unacceptable nitrate concentrations downgradient from the drainfield under design loading conditions. In this case the most cost-effective solution incorporated a denitrification unit process so that effluent concentrations were less than 10 mg/L nitrate-N.

 

Modeling the Effect of Discharges from On-Site Systems and Sewers on Stream Nutrient Loading in Turkey Creek Watershed using SWAT and WARMF Model
Presenter: Mengistu Geza
Co-Author: John E. McCray

Watershed based pollutant transport studies have usually ignored the impact of on-site septic systems (OWS) and point source discharges from Wastewater Treatment Plants (WWTPs) on the quality of surface water. OWS can potentially be a substantial source of nutrients to surface waters. Point discharges from WWTPs can also contribute to the stream pollution from nutrients especially if treatment efficiency at the WWTP is low. Evaluating nutrient loading from OWS is a challenging task because most non-point source (NPS) pollution models are not specifically developed to track the fate and transport of nutrients from OWS. Soil and Water Assessment Tool (SWAT) model is most often used in TMDL assessments. The model has not been modified to directly simulate OWS but has been used to evaluate the effect of OWS by making certain assumptions. In Contrast, Watershed Analysis Risk Management Framework (WARMF) model is adapted to simulate OWS loading. The 126-square-kilometer Turkey Creek watershed is located in Jefferson County, Colorado. SWAT and WARMF model hydrologic calibration was performed using data from the gage station located at Turkey Creek at mouth of canyon near Morrison. Since there is currently no direct method to input OWS derived nutrients, the management operation of the SWAT model is used to apply effluent from OWS as nitrogen and phosphorous fertilizer input. Nitrogen and phosphorous contributions per housing unit are estimated using population estimates from Census data. Both models were calibrated to available observed data. After establishing a base case, scenarios related to OWS were tested using both SWAT and WARMF. These scenarios include the conversion of existing OWS to centralized sewers. The scenario runs provided information to evaluate the trade-offs between OWS and centralized sewer systems and the general impact of OWS on surface water quality. WARMF is adapted to accept septic tank effluent, process it and discharge the treated effluent into the topsoil layer of the watershed model. The management scenario presented in this study illustrates how WARMF can be used as a decision tool to compare OWS and centralized sewers. It was possible to demonstrate that WARMF is a more suitable tool for watershed studies involving OWS pollutants. The limitation in using SWAT model is either precipitation or irrigation water must be relied upon for carrying OWS effluent downward. It is important to note that porosity and infiltration rates in OWS may decrease with time leading to potential hydraulic failure of the OWS. This is our future research focus to evaluate the possibilities declining efficiencies of OWS with time as a result of hydraulic failure. The study showed that for this watershed and for the existing treatment efficiencies at the WWTPs, OWS is more efficient in removing wastewater pollutants than WWTPs. Thus, the results indicate that for the conversion of OWS to be beneficial a very high level of treatment would be required at the WWTP.


 



Earthworms and Composting Worms—Basics Towards Composting Applications
Presenter: Jaya Nair
Co-Authors: Kuruvilla Mathew and Goen Ho

Earthworms are used in biomedical research and environmental toxicology analyses all over the world. It has also been one of the key species of interest in waste management applications. Ecotoxicological studies uses earthworms as an indicator of the degree of contamination and remediation. The assessment is based on the survival, overall activity, cocoon production, reproduction, population and biomass production. In their living environment earthworms are often compromised by many factors that affect their survival such as pesticides, herbicides, acidity, alkalinity and other adverse physical conditions. As a result earthworms were considered as the key species for monitoring to verify the health of soil ecosystems. There are over 3500 sps of earthworms around the world and some have the potential to be used specifically as the composting worms in the area of waste management. The significance of the species for composting applications depends on their nutrition and feeding and their adaptability to a range of physical and chemical conditions. In that context understanding the physiology and ecology of worms is imperative in application to modern science. This paper addresses the general ecology, physiology and adaptability of worms to consider them for vermiculture and waste treatment.

 

Implementing the H2S Method for Testing Bacterial Quality of Drinking Water in Communities
Presenter: J. Nair
Co-Authors: K. Mathew and G. E. Ho

The H2S method for testing microbial quality of drinking water has recently received wide interest as it has many advantages over any other method for microbial testing of drinking water currently available. Because of the use of sulphate reducing bacteria as an indicator organism rather than the standard coliform bacteria (WHO, 1997), comparison between these two methods can be confusing. The main constraint lies in the fact that both organisms have disadvantages as an ideal indicator organism. The presence of coliform bacteria does not give a true indication of contamination from fecal origin particularly in warm tropical waters and the absence of coliform bacteria does not provide complete safety indication as to the absence of many human enteric pathogens. The H2S method correlates well with the coliform method. The main advantages of the method being highly economical, easy to use and interpret minimum requirements of facilities and long shelf life of the media at room temperature. The requirement for an on-site and easy testing method is more for the remote areas where normal laboratory services are unavailable and in places where the standard methods could not be economically affordable for routine testing. It is in these cases that we need to weigh the benefits and drawbacks of the method. This paper will give an over view of the H2S method, how to conduct the test and the factors to consider when implementing a routine water testing program in communities.



Aquatest—A Global Research Project to Develop Simple, Accessible Low Cost Tests to Quantify Fecal Contamination of Water
Presenter: Mark D. Sobsey
Co-Authors: Anthony P. Davis, Ranjiv Khush, J. Wright, and Stephen Gundry

Safe drinking water is considered a fundamental human right, yet the majority of the World’s people lack sustainable access to water that is essentially free of fecal contamination. As a result, they suffer from waterborne infectious diseases that cause an enormous global burden of diarrhea and other infectious diseases and alarming high mortalities, especially of infants and children. A major obstacle to sustained provision of safe water is to know when water is fecally contaminated and when it is not, based on simple methods to detect and quantify fecal bacteria or other microbial and chemical markers of feces and its attendant pathogens. Current tests for E. coli and other bacteria indicative of fecal contamination are not readily accessible to or affordable for people in developing countries. Current methods require expensive materials, laboratory resources and trained personnel that are simply not available in most developing countries. To remedy this critical situation a team of researchers has embarked on a plan to develop simple, accessible and affordable tests for E. coli and in the future possibly other fecal indicator microbes in water. The goal is to create a test(s) that is readily available globally, low cost (less than US$ 0.1 per sample), quantitative within order of magnitude (log10) values, performable in the field by relatively unskilled persons, and not necessarily requiring a specific incubation temperature in a very narrow range. The project is organized as a phased approach, with initial efforts to simplify, increase access and reduce costs of existing E. coli tests, then develop a next generation E. coli culture test made readily available in the developing world and finally develop tests that provide rapid results based on other analytical endpoints (such as gene expression or detection of specific metabolic products and antigens), rather than require overnight or longer incubation periods. Initial studies of existing E. coli tests indicate that some can provide reliable results when they include Beta-glucuronide substrates giving colored (chromogenic) hydrolysis products, when they are simplified by being performed in inexpensive plastic containers (e.g., bags) and when incubating samples at ambient temperatures of tropical climates rather than at 35-37oC. In related work, field comparisons of water samples analyzed simultaneously for E. coli and hydrogen sulphide (H2S) bacteria indicate that quantitative versions of both tests provide comparable estimates of fecal contamination levels. Hence a quantitative H2S test also has promise as a simple, low cost test for fecal contamination of water in the developing world.


 



Rainwater Harvesting and Runoff Pollution Control in Beijing
Presenter: Wu Che
Co-Authors: J.-Q. Li and H.-Y. Li

Beijing is facing a crisis of available water due to the scarce amount of water resources lower than 300 m3/ca. This situation has actually become a bottleneck controlling the sustainable development of society and the economy, and water pollution is decreasing water resources available for use even further. In practice, there is only up to 230 million m3/year of rainwater runoff in the city area of Beijing, which is directly discharged into rivers and sewers. In this article, rainwater harvesting and its runoff pollution control in Beijing are discussed, including the strategic policies, guidelines and techniques to address their problems. Based on the analyses of runoff rainwater quality from different catchments, the patterns and concentrations of initial and average rainwater runoff are summarized. As a result, the initial control depths of rainwater from roofs and roads are identified at 2-3 mm and 6-8 mm respectively. The initial COD and/or SS concentrations of rainwater runoff from roads are about 3-4 times higher than that from roofs. Therefore, some typical technical processes of direct harvesting, infiltration and integrated utilizations are proposed in the article. Finally, the effect of green roofs on rainwater runoff pollution is also described.
Keywords: Rainwater harvesting; runoff pollution control; green roofs

 

Capacity Development for Sustainable Water Management: The Case of Rainwater Harvesting in Ontario
Presenter: Khosrow Farahbakhsh
Co-Author: Don Lewis

Investigating the potential for implementing large-scale rainwater harvesting in an urban environment has propelled our research team at the University of Guelph to take a closer look at the underlying processes involved in widespread implementation of alternative water management approaches. What began as a feasibility study has since turned into a project focused on capacity development for large-scale rainwater harvesting. The shift in focus has been both challenging and rewarding. It has brought us out of our engineering comfort zone and has exposed many of the vulnerabilities of the technology-focused approach. This paper will attempt to share lessons we have learned in encouraging a large-scale shift from conventional methods to a more sustainable and integrated approach to water management.

 

Innovative Rainwater Harvesting and Management Practice in Korea
Presenter: Mooyoung Han, Seoul National University, Korea
Korea is recognized as a most difficult area for rainwater management because of the combination of its adverse weather and its geological conditions. The distribution of rainfall is uneven, which is typical of monsoonal areas, and about 70% of the country is mountainous with steep rocky slopes. In this paper, a new paradigm is suggested where rainwater is managed on a decentralized basis, being controlled near its source and involving local activities. The concept of multipurpose rainwater management is suggested, to create a more efficient management system, and some examples of proactive management are introduced. Multipurpose and proactive rainwater management is very helpful to the sustainability of developed countries, but it also helps to meet the Millennium Development Goals (MDG) for developing countries.

 

The Responsive Governance and Innovative Technology Transfer: A Development Model for Village Self Reliance
Presenter: Joseph Thanikal
Co-Authors: T. Sukumar, Elango, and R. Shanmugam

A responsive system must be elected by the people to fulfill the felt needs by democratic means and ways. The system need to involve general public in identification of available schemes (based on needs), programmes, planning, and scheme implementation. All the programs need to be transparent before and after implementation. The responsive system becomes successful through community participation. A case study was carried out at Odanthurai Panchayath (an administrative identity), situated at Coimbatore, Tamil Nadu, south of India. The panchayath consisting of 9 hamlets was found to be self content. The village has been successful in providing all the amenities for its people through implementing innovative technologies based on its need.

 

The Solaire: A Case Study in Urban Water Reuse
Presenter: Edward A. Clerico
In 2000, the beginning of the “green” build movement opened new water reuse opportunities via projects that demanded a higher level of environmental protection and lower impact on natural resources. Decentralized water reuse systems have emerged as an attractive, unique and innovative approach to water, wastewater and stormwater needs for new developments even in urban areas that possess large capacity infrastructure. In New York City, the area in lower Manhattan that is known as Battery Park City began an intensive environmental initiative to demonstrate new approaches for sustainable urban development. The Battery Park City Authority adopted very stringent environmental guidelines and as a result, launched the beginning of urban water reuse projects in the United States of America. There are currently four operating decentralized water reuse systems in Manhattan and three additional water reuse projects in various stages of planning or construction. The Solaire was the first such system and it serves as an excellent case study demonstrating the details and nuances of this concept. This report looks at the design characteristics and performance results for The Solaire, particularly from an economic perspective.

 

Innovative Strategies: Controlling Biofilms and Biofouling in Water Treatment by Blocking of Microbial Communication Network
Presenter: Yehuda Cohen
New water sources are urgently needed leading us to focus our attention to water recycling on the one hand and to the desalination of brackish and seawater on the other hand. The membrane technologies that were developed to meet these urgent demands for new water require their use in waters with high biofouling potential. A more in-depth understanding of environmental regulation of biofilm development is essential in order to predict biofouling potential and develop innovative tools for water treatments on small and larger scales. The old strategy of “If you have bacteria- kill it and solve the problem” does not work – dead bacteria are the best food for enhanced microbial biofilms development and with it severe biofouling problems. Recent findings in Microbial Ecology provide exciting new innovative strategies for controlling biofilm development and dispersion without the need for extensive use of toxic biocides.

 

Biostructure Application in Water and Wastewater Treatment
Presenter: Stanley Lazarek
Co-Author: Wlodzimierz Lawacz

Lamellar structures and plastic panels with tufts of fibres were placed in lakes and reservoirs and in outflow canals of larger wastewater treatment plants. The lamellar structures had extended surface area measured in hectares per one cubic meter. The structures provided immersed beds for biofilm development that facilitated restoration of degraded lakes and reservoirs and served as bioreactors effectively polishing effluents. Horizontal and vertical surfaces in the structures can direct water-flow in a desired direction. When positioned as barriers in reservoirs and harbour canals the structures can utilize energy of waves and water currents to aerate bottom sediment. They provide favourable environment for a massive growth of periphyton. It was observed that the bacteria content in water which passed the barriers was reduced by three orders of magnitude. At the same time, concentration of nitrogen and phosphorus decreased considerably. Between 10 and 20 kilograms of dry matter of periphyton were obtained in one m3 of the panel structures after 12 months of immersion. During that period, forty species of algae and all taxonomic groups of aquatic invertebrates were represented on the colonized surfaces. Dreissena polymorpha dominated the biomass in respect of weight.
Keywords: Biostructures; Periphyton; Biological Barriers; Wastewater; Aquaculture

 

Theory and Practice of Eco-Village Planning in China
Presenter: Daiyu Zhang
Co-Author: W. Ouyang

For the sustainable development of society and the economy, the vast expanse of existing villages in China will have to be deliberately re-planned and re-constructed. Under the circumstances, eco-villages tending towards a recycling pattern are an approach to this sustainable concept. In this article, the theory of eco-village planning is proposed, and the planning theory being practiced at a village near Beijing is described. The practice of the eco-village has been selected as a demonstration project, which is financed by the municipal government of Beijing.
Key words Eco-village; village planning; treatment of waste water/waste


Research and Development of Decentralized Wastewater Treatment System in China
Presenter: Xiaodi Hao
Co-Authors: F.-G. Qiu and J.-Y. Zhu

China is facing both water pollution and shortage. Decentralized wastewater treatment systems (DWTSs) are superior in combination with wastewater reclamation. In this article, the R & D situation of DWTSs is fully reviewed and evaluated. Among others, biological aerated filters (BAF) and Ecosan are proposed as the alternatives of the future DWTSs.
Keywords Decentralized wastewater treatment systems (DWTSs); septic tanks; BCO; BAF; membrane bioreactors; lagoons; wetlands; Ecosan