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2005 Annual Conference Proceedings

 

NOWRA TECHNICAL CONTINUING EDUCATION PROGRAM SESSIONS

NOWRA 14th Annual Conference – October 10-13, 2005
CLEVELAND, OH



Advanced Onsite Treatment and Dispersal Offers New Solution for Mobile Home Parks - Steve Braband
Many mobile home parks in California emerged from a “getaway RV park” into a permanent home site.  Also occurring are changes in the wastewater treatment system.  This presentation addresses many of the challenges associated with the project ranging from permit issues to identifying a suitable and reliable disinfection system


Renovating a Failed Drain Field with Highly Nitrified Septic Tank Effluent - Robert F. Pickney
The possibility of consistently renovating failed drain fields could have significant impact on current and future regulations and policies.  This discussion addresses the design, construction, and results of a renovation project, and includes a comparison of oxygen demand in field lines when using treated or untreated septic tank effluent.


Onsite Sprinkler Irrigation of Treated Wastewater - Michael Rowan, PhD.
This presentation will provide an overview of wastewater irrigation systems, beginning with a comparison between traditional irrigation and wastewater irrigation.  The audience will learn where onsite irrigation is appropriate, what permits are required before installation and the step by step process for designing the irrigation system.


Distributed Sewer:  The Demand Side - Craig Lindell
The town required the developer to build a treatment system to accommodate an existing supermarket strip mall and a variety of restaurants and retail outlets across the street. The combined flow is 40,000 GPD high strength wastewater.Essentially. the towns need to eliminate failed septic systems was exchanged for zoning variances that enabled Lowe’s to build a new store.This exemplifies the potential of a distributed infrastructure.


Evaluation of Ecological Small Scale WW Systems within the Swedish Local Investment Programme - Peter Ridderstolpe
The Swedish Local Investment Programme (LIP) granted ecological small-scale wastewater systems during the period 1998-2002. This paper presents results from an evaluation of these systems considering the aspects: user experiences, organisational and administrative experiences, economy and environmental performance. The compared systems were: Dry closets with urine diversion, Water closets with urine diversion, blackwater systems, composting toilets and small-scale wastewater systems.


Lessons Learned from a Level 5 EPA Management System - Jim Carroll
Southern Iowa Rural Water Association (SIRWA), a quasi public government body proposed to own and operate onsite wastewater treatment and disposal systems for each residence in Shannon City for the purpose of providing affordable and effective wastewater treatment.




Decentralized Wastewater Solutions for a Historic Mill Village - Justin Jobin
This presentation describes the results of a project that focuses on planning to meet wastewater needs for the future.  Geographic information systems were used to evaluate water quality impacts of onsite systems to local water supplies, using multiple indicators of potential impact, including estimated nitrogen inputs to groundwater based on a simple mass balance model.  Each parcel in the central village was categorized according to their suitability for hydraulic function of onsite systems based on lot size and soils, then re-evaluated based on environmental constraints such as location within buffers to public wells, waterbodies and wetlands.


Onsite Technology for Managing Primate Wastewater - Scott Wallace, Ph.D., P.E.
The Great Ape Trust has developed a state-of-the-art research facility to investigate the communication patterns in higher primates (Orangutans and Bonobos).  One of the challenges facing the facility designers was wastewater treatment.  While sewer service was available from the City of Des Moines, Iowa, the remote location of the facility made connection to the regional sewer system very expensive.  The Trust preferred an onsite, environmentally friendly treatment system over connecting to the regional sewer network


Pilot test of Denitrification reactor for Large Subsurface Wastewater Treatment - Mark O. Liner, P.E.
The integration of denitrification to onsite systems introduces significant challenges in that typical academic and technical approaches are more difficult to apply due to the low flows and significant diurnal variations are presented.  However, due to their smaller size, onsite systems do lend themselves to more robust (less sophisticated) solutions.  One such solution for denitrification is the use of completely mixed, submerged, attached-growth media with a supplemental carbon feed.
 

Sewering Narrow Lake, MI - Working Outside the Box - Larry Stephens, P.E.
Previous attempts by other engineering firms to find an affordable solution using traditional methods had failed, which led to the consideration of several innovative approaches to both collection methods and treatment means.  Now in the design stage, this project will move to construction during 2005, and incorporate in the system design provisions such as a combination of Septic Tank Effluent Gravity (STEG) and Septic Tank Effluent Pumping (STEP) systems, installation of pressure sewer using directional boring techniques, shared septic tanks, remote system management, packed-bed geotextile filters housed in a building, and unique methods of communication.


Wastewater Management on a Remote Barrier Island - Scott Wallace, Ph.D., P.E.
The Boy Scouts of America operate a camping program on Big Munson Island, a remote barrier island in the Florida Keys.  Twelve campsites are scattered across the island, located less than five feet above sea level.  As part of their environmental stewardship program, the Scouts have upgraded facilities on Big Munson Island.  Composting toilets have been used for years to manage wastewater on the Island.  Recently, the Florida Department of Health requested that the Scouts develop systems to manage greywater generated at each camp site from food preparation and washing dishes.  Conventional treatment units are poorly suited to this challenge.
 

Construction Observation Training - Matthew Wildman, P.E.
Presentation discusses how to effectively train construction observers and why this training is critical to the overall success of the project.


Decentralized System Management - Bryan DeSmet, P.E.
This paper discusses the various management models available for use in the ownership of decentralized wastewater treatment systems, along with the strengths and weaknesses of each of these models.  One model that has been developing over the last 3 to 5 years is the establishment of a rural water agency as an RME for decentralized systems. This will be presented as a case study providing specific project information, along with a discussion of how the project was handled including design, permit review, construction, and operation.




Streamline Process for Certified Installers to Repair Nonfunctioning Onsite Systems - Anish Jantrania
Information on projects where properly trained installers have done repairs and replacement work for failing or inadequate onsite systems is rovided with suggestions as to how the industry can implement training and certification programs so that the installers can fix the problems associated with failing septic systems in a timely and cost-effective manner.


Educating Regulators About Onsite Wastewater Treatment - Eli Hacker
Health officials in 88 counties and environmental engineers in five districts issue permits for onsite wastewater treatment systems throughout Ohio.  Educating this large and diverse audience about advances in onsite wastewater treatment is a challenge.  A detailed audience and needs analysis is being conducted to learn more about preferred learning styles and what regulators need-to-know.


A Satisfaction Survey of System Owners - George Loomis
During the past seven years, the University of Rhode Island's Cooperative Extension Onsite Wastewater Training Center installed 56 demonstration advanced wastewater treatment systems at local Rhode Island home sites.  Many of these systems offer pioneering technology for advanced nitrogen and bacterial removal as well as custom design for challenging site conditions.


Online Community Resource Center - Justin Jobin
A presentation about the community wastewater management online resource center developed at the University of Rhode Island for use by communities to start up a wastewater management program.  Examples from Rhode Island communities such as Block Island, Charlestown and others describe the valuable lessons learned from these experiences.


Case Study:  Implementation of a Model 2 EPA Management Guideline by a Privately Owned Small Business - Michael Stephens
The experiences of SCS Systems LLC, to actively marketed itself as a provider of not only maintenance services, but of overall management and monitoring of septic systems that fall under the Model 2 program of EPA’s Voluntary Management Guidelines (March 2003) are provided in this presentation.  These systems include more complex treatment systems with mechanical components for individual homes, small commercial businesses, and small cluster systems.  Actual experiences relating to program descriptions, benefits, and limitations focus on a small business ability to offer these services to these various clients under various regulatory structures.


Degradation of Turkey Fat - Rashmi Singh Gaur
Restaurants, food processing plants and dairy industries produce wastewater containing high levels of animal fat. The accumulation of animal fat can cause problems in wastewater treatment plants.  Sand bioreactors show great potential to treat high-strength wastewater, however, high levels of fat can cause surface clogging.  The objectives of this study were to consider the use of coarse sand and/or pea gravel caps to serve in pretreatment and go on to find the optimum depth.  These studies will be helpful to anticipate the economic viability of proposed sand bioreactors for treatment of food plant and restaurant wastewater.


Strength  and Sources of Pollutants and FOG - William Stuth
This presentation provides an overview of changes made to a 24-year old onsite system within a successful restaurant located near a shell fish growing area in the Pacific Northwest.  The original system, designed and installed 24 years ago under prescriptive regulations, had been repaired three times within a 10-year period. When the onsite system failed the fourth time, in 1991, it was replaced with a performance based system incorporating many unique features and to date the system in still in operation.  These unique features of this new system will be shared in this presentation


Food Service Establishment Wastewater Characteristics - Bruce Lesikar, PhD.
Food service establishments using onsite wastewater treatment systems are experiencing pretreatment system and/or drain field hydraulic and/or organic overloading.  This study included characterization of four wastewater parameters (BOD5, TSS, FOG, and flow) and an analysis of management practices from 28 resturants located in Texas during June, July and August 2002.




Removing Barriers to the Evaluation and Use of Decentralized  Wastewater Technologies and Management - Carl Etnier
A key step in finding solutions is to thoroughly understand each barrier and its causes, discussing them with members of the engineering field as well as stakeholder groups that influence decision-makers. While a bias centralized solutions exists, there important case studies to learn about communities and engineers who have tried decentralized approaches and have been very satisfied with the results. Facing challenges and finding solutions is the focus on this session.


Achieving Sound Watershed Planning Through Decentralized Wastewater Management - Richard Otis, P.E.
In 1997, USEPA declared that “adequately managed” onsite wastewater treatment systems are  “viable, long term alternatives to centralized wastewater facilities…particularly in small and rural communities”.  This declaration bestowed credibility on onsite and cluster systems, which has helped to overcome the perception that onsite systems are only poor interim solutions to be used only until sewers are extended.  Yet, the full potential of onsite/cluster systems in helping to achieve our nation’s public health and water quality goals is unrealized because we regard them as an alternative to central sewerage rather than a complement to central sewerage in providing safe and effective service to all residents and establishments in a watershed.


Beyond The End Of The Pipe -- Will There Be A Shortage Of Capacity For Septage Management - Carl Etnier
Responsible management of onsite wastewater treatment systems includes regular checking of septic tanks and pumping when needed. The septage is generally taken to a wastewater treatment plant for processing or land applied.


Crow Wing County Wastewater Management District - Craig Gilbertson
To help assure protection of human health and the quality of the waters, a Joint Powers Board (JPB) of Crow Wing County and the Thirty Lakes Watershed District was established.  Based on wastewater treatment solutions, documented in a wastewater management feasibility plan completed by the JPB and the Implementation Team (citizen volunteer advisory board to the JPB), a county wide decentralized sanitary management district with pilot subordinate districts is being established for the region.


Onsite Treatment System Management - Albert Royster
Presentation addresses "Ten ways to extend the Life of the Septic System" -- regarding things that enter the waste stream that should be recycled or reused -- together with several myths of what people add to a septic system.


Establishment of Responsible Management Entities - Robert Pickney
There is a growing trend in the decentralized community for Responsible Management Entities to provide ownership, operation, maintenance and replacement of decentralized wastewater systems.  Utilities are leading the trend for this service.  This management structure is providing a cost effective way to manage wastewater with sound financial and environmental principles.


Defining the Business Attributes in Successful RME's - John Murphy
The EPA recognizes Responsible Management Entities (RMEs) as excellent ways to protect the nation’s water resources by ensuring the long-term management of decentralized wastewater treatment systems.  Thus, the Water Environment Research Foundation, using funding from the EPA, commissioned a study team led by the National Rural Electric Cooperative Association (NRECA) to evaluate existing RMEs in order to identify business attributes that are common to successfully operating RMEs.




Performance Based Authorization - a New approach to Technology Authorization - Carl Thompson
Throughout the United States, state and local regulatory authorities are challenged with improving onsite wastewater treatment to protect the environment, revising and enforcing existing regulations and codes, and developing new codes in response to the ever-changing technological environment.  Complicating this matter are staff and funding cuts that are decreasing time and resource availability.  In response, some manufacturers are working closely with those in charge of regulating onsite wastewater programs. Together, they are developing new ways to standardize the process of authorizing the use of gravelless (or non-gravel) drainfield technologies.  This includes guidelines and provisions for verifying new technology, system sizing and design, and the testing and reporting of product performance.


Development of  EPA MOU - A National Action Plan - Joyce Hudson
The U.S. Environmental Protection Agency (EPA) Office of Wastewater Management oversees the nation’s effort to ensure that domestic, commercial, industrial, and other wastewaters are treated and discharged in a manner that does not cause deleterious impacts to human health or ecological resources. Malfunctioning onsite and clustered (decentralized) wastewater treatment systems have been implicated in health and environmental impacts in the past, due mostly to poor system management practices, e.g., inadequate planning, improper design, faulty construction, and lack of appropriate operation, maintenance, inspection, and residuals practices.


Civil Penalities for Enforcement Requires State Law in VA - Robert E. Lee
When Loudoun County, Virginia initiated a comprehensive management program for onsite wastewater treatment systems, little did they realize it would take drafting, legislation and moving it through the Virginia General Assembly and to the Governor for enactment.  Virginia is a Dillon Rule state.  What that means in common terms is that if the state doesn’t give local government specific authority to do something they cannot do it.  In Virginia the state authorized local governments to regulate wastewater.  But that doesn’t necessarily mean manage.


Lake County Seeks Comfort and Security in a Performance Code - Tony Smithson
In response to the rapid growth, increasing demand for the small lake shore properties, and the challenge with replacing thousands of existing systems that had reached the end of their useful lives, LCDH adopted a “flexible” prescriptive code to allow alternative systems for non-conforming lots.  While this new code eased the pressure on the LCDH staff in dealing with the rapid development in unsewered areas, the staff was concerned over the performance of the alternative systems that were being permitted.


New Developments in American National Standards for Onsite Treatment Systems and Components - Tom Bruursema
The scope and capabilities of onsite wastewater treatment systems and components continues to grow.  To keep pace with this growth, the American National Standards (NSF/ANSI) Standards have likewise been expanding.


Point of Sale:  A Success Story - Roger Bard
In 2001, St. Louis County established an individual sewage treatment (ISTS) property transfer inspection program in northeastern Minnesota.  The compliance inspection program is designed to upgrade failing septic systems without penalizing systems still treating and dispersing wastewater effluent. Public acceptance of the programs is based on performing the inspections when financing is more readily available and the parties to the land exchange have the opportunity to negotiate issues concerning system upgrades.




Phosphorus Geochemistry in Septic Tanks & Phos-Sand Innovative Phosphorous Removal System - Pio Lombardo
The role of phosphorus (P) loading from septic systems on water quality degradation remains an issue for onsite wastewater systems.   Onsite systems represent a substantial source of P and the subsurface mobility is not fully understood.  Recent studies have observed variability in P mobility between septic system sites on similarly textured sand.  This appears to be due to P attenuation in the soil.


Decentralized Nutrient Removal, Microcontaminant Destruction and Dininfection Using a Novel Reduction Oxidation Platform - Glen Dombeck
An emerging challenge for onsite wastewater treatment is the need to enhance reuse capabilities while achieving very stringent performance requirements.  A disinfection component is often necessary to prevent introduction of pathogens into groundwaters and is a requirement for higher levels of reuse.  Another need is for reliably low effluent concentrations of total nitrogen and total phosphorus.


Micro-Scale Evaluation of Phosphorus Management - Carl Etnier
Nutrient enrichment is a leading cause of water quality impairment in the waters of the United States, and wastewater inputs are a source of phosphorus pollution in aquatic ecosystems. Although there has been considerable focus on reduction of phosphorus in effluent from public wastewater treatment plants in the U.S., the environmental impacts of onsite wastewater treatment systems have received much less attention.


Treatment Performance of Innovative and Alternate Systems - George Loomis
Advanced or innovative and alternative (I&A) decentralized wastewater treatment systems have been used successfully for over two decades to achieve high levels of BOD, TSS, nutrient, and bacterial removal.  New advanced treatment systems are emerging on an almost routine basis, some having been subjected to more testing than others.  Testing centers have been used to evaluate treatment performance of certain technologies under controlled conditions.    Several decentralized demonstration projects have monitored treatment performance of various technologies in an effort to determine system performance under actual use in the field.


Holistic Approach to Nitrogen Management in Watersheds - Pio Lombardo
This paper addresses the development of a Holistic Approach to Nitrogen Management in a Cape Cod, Massachusetts watershed.  The Great, Green, and Bournes Ponds area in Falmouth, Massachusetts are classified as “significantly impaired” or “severely degraded” due to excess nitrogen loading from non-point sources.  Approximately 50 percent of the nitrogen loading to the ponds comes from septic systems, 25 percent from fertilizers, 20 percent from residual atmospheric deposition, and the remaining five percent from various other sources.  Water quality is fiscally important to Falmouth.


A Preliminary Evaluation of the Amphidrome Systems in the Pinelands of New Jersey - Jill C. Renzi
The New Jersey Pinelands is a National Reserve and the largest body of open space on the Mid-Atlantic seaboard between Richmond and Boston.  It is underlain by aquifers containing 17 trillion gallons of some of the purest water in the nation.  This important ecological region is 1.l million acres in size and occupies 22% of New Jersey’s land area. In order to protect this ecologically sensitive area, the Pinelands Commission established strict guidelines for approving wastewater treatment systems in the area.  The five currently selected technologies are being closely monitored especially with respect to the effluent total nitrogen limit of 14 mg/l.




Operation and Maintenance Service Provider Project Summary - Bruce Lesikar
The Operation and Maintenance (O&M) Service Provider program is being established to set standards for using best practice of providing onsite wastewater treatment system service.  The focus of these materials is single-family residential systems.  Through routine service visits and aproper maintenance, onsite wastewater treatment systems become a permanent part of the wastewater infrastructure.


Managing Long Term Solutions to Failing Septic Systems - John Murphy
This organization 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 failing septic systems.  This presentation summarizes results to date of the Table Rock Lake national demonstration project.


Designing and Installing Onsite Systems for Ease of Maintenance and Increasing System Life - James C. Converse, PhD.
This presentation examines how systems should be designed and installed to make it easier to perform operation and maintenance on the total system.   With the increased emphasis on operation and maintenance, making onsite systems operator-friendly is important, even with the conventional septic tank soil absorption unit.


Management of Recirculating Sand Filters - Theodore Loudon, PhD
Management of Recirculating Sand Filters (RSFs) involves regular monitoring and occasional maintenance activities.  Monitoring requires not only looking at effluent water quality but also looking at physical and biological aspects of the sand/gravel filter to access its functional characteristics.  The service provider must be familiar with signs of good and potentially harmful biological activities.


The Clogging Incidence Of Drip Irrigation Emitters - Michael Rowan, PhD.
Four types of drip irrigation emitters from three manufacturers were used to distribute effluents of different qualities.  The control emitters were embedded in commercial grade landscape dripline, which was not designed for use with treated wastewater.  The experimental emitters included one non-pressure compensating, turbulent flow emitter and two pressure compensating diaphragm regulated emitters.


A Submerged Attached Growth Biorreactor Coupled with Membrane Filtration for Water Reuse - P.B. Pedros, PhD.
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 onsite wastewater treatment plant. The single greatest obstacle to the development at The Jefferson in Bellingham, Massachusetts was the proximity of the site to the public drinking water supply well. To protect groundwater supplies, the Massachusetts Department of Environmental Protection, (DEP) has classified, groundwater discharges within such areas as a form of water reuse which are governed by strict regulations.


Urine Separation - Swedish Experiences - Bjorn Vinneras, PhD.
The environmental effects of urine separation have been investigated in several studies. They have all concluded that compared to a conventional sewage system, urine separation will recycle much more plant nutrients, especially nitrogen and will have lower water emissions of nutrients. Generally, urine separation has also been found to save energy. Urine separation has in all studies been found preferable to the conventional system form an environmental point of view.
 




Cost Effectiveness of Cluster Systems - Scott Wallace, P.E.
Cluster systems have proved to be an invaluable solution to provide small communities with high quality wastewater treatment at an effective cost while protecting the character of the community.


A Rational Method for Determining Design Flows for Cluster Systems - Larry Stephens, P.E.
Cluster wastewater treatment systems (or community systems) have become a popular use in many parts of the country. This approach permits homes to be clustered on less property, sometimes surrounded by green space, and the wastewater treatment system to be located in an area where the soil conditions are most appropriate.  The use these options allows planners to provide for more housing for future residents in less space, thus helping to prevent urban sprawl, and preserve more green space.


Streamlining the Design and Regulatory Review Process - David Kalen
Ever since regulatory approval was granted for innovative and alternative (I&A) onsite wastewater technologies in Rhode Island, the design community and the regulatory review agencies have struggled with different styles and approaches to achieve a successfully approved design application.


Hydraulic Properties of Drainfield Trench Biomats formed in Georgia Soils - Larry T. West, PhD.
Understanding hydraulic properties of biomats formed in different soils is critical for predicting long-term wastewater acceptance rates and for computer simulation of wastewater infiltration under different drainfield configurations.


Soil Properties Iinfluencing Onsite Systems - Daniel Wheeler
Identifing the importance of the soil properties that must be evaluated and understood at each onsite evaluation and discuss the role of additional soil properties on a more localized level is the focus of this presentation.  If local regulation does not require the accurate determination of these soil properties, there will likely be issues with onsite systems in these areas.


Lake Elmo's Decentralized Wastewater Management Program - Curtis J. Sparkes
Presentation chronoicles the long term development of a decentralized wastewater management system, the land use factors that drove their city to cluster systems, a plan for old village redevelopment the operation issues and ultimate need to address ownership and management of a wastewater system


Design of Pressure-Dosed Systems Using Spreadsheets - Larry Stephens, P.E.
It is now a well established fact that the soil absorption component of an onsite wastewater treatment system functions better from a treatment perspective, and, in general, will have a longer life expectancy if the treated effluent is equally distributed over the entire soil interface.  This is particularly important as the size of the system increases.


When are "Poor Perking" Soils the Best Soils? - Cliff Stein
This presentation is designed to stimulate thinking by challenging conventional wisdom in the use of “poor perking” soils for land based wastewater treatment and dispersal systems.  Who among us would prefer a site with moderately well drained slowly permeable soils over a site with well-drained highly permeable soils?




Working with Communities to Achieve Wastewater Management Goals - Karen McBride
Many communities are unaware they have options when it comes to wastewater treatment and disposal, especially wastewater management. Knowing when communities are ready, where to begin, what tools to use and how to move the community to the next step will be offered. We all know that education is one of the most important keys to a successful onsite wastewater management program, but how do we keep our communities empowered? How do we work as a community to ensure it will be the best solution and not end up going backwards? This presentation discusses how to keep your community engaged in their vision and how to work together to get the community motivated.


Watershed Protection in Cuyahoga County - Harry Stark, RS
This presentation focuses on the programs underway at the Cuyahoga County Board of Health’s (CCBH) Watershed Protection Unit which includes the HSTS Operation and Maintenance (O&M), Water Quality, Beach and Marina Program, Stormwater activities. It also provides a history of the State of Ohio’s sewage rules, the Watershed Protection Unit and its programs and the impact they have had on our communities and watersheds.


Risk Assessment of Decentralized Systems in High Priority Areas - Mary Clark
The City of Malibu relies on onsite wastewater treatment systems for protection of valuable water resources. A team of consultants and City staff conducted a three-year risk assessment/risk management study in a high-priority area of the city, that included 400 properties around Malibu Creek and Lagoon, and the surfzone along Santa Monica Bay. Stakeholders, including residents, regulators, and environmental advocacy groups, were essential to the study’s success.


Impacts of Onsite Systems on Ground Water in Karst - Eberhard Roeder, PhD.
Karst, a landscape formed in dissolving limestone, is widespread in Florida and other states.  The dissolution of rock by water over time leads to the formation of solution holes and conduits that act like a network of pipes.  This in turn, can be expected to affect the transport of onsite sewage treatment and disposal system (OSTDS) effluent in the groundwater, in particular increasing its velocity and the distance.  To clarify these effects, Florida Department of Health (DOH), with additional funding from EPA’s Gulf of Mexico Program, initiated a study of onsite systems in a karst area.


Modeling Phosphorus Reaction and Transport at an Experimental Onsite Wastewater Site - John E. McCray, PhD.
Phosphorus (P) from onsite wastewater systems (OWS) is often considered to be a water-resources problem because of potential eutrophication of sensitive wetlands and other surface-water bodies.  However, very little quantitative research has been conducted for P fate and transport from OWS.  In particular, the relative importance of two simultaneous P reactions, soil sorption and chemical precipitation, has not been rigorously addressed.  In addition, sparse research is available on the relative importance of the site-scale variability in P sorption capacity, precipitation rates, and soil-water hydraulic parameters on P transport.