Septic Systems and Waste Management
Integrated Water Design (IWD)
Congress recently approved a National Decentralized Wastewater Demonstration Project in northeastern North Carolina. The project is called the Pasquotank River Watershed Project. It is one of six special water management projects funded across the United States by Congress. This project will be jointly led by the Albemarle Regional Health Services Agency and the College of Agriculture and Life Sciences at North Carolina State University as well as North Carolina Cooperative Extension. It will also include other partners. The project work plan is currently being developed. The project will start after EPA has approved the project work plan.
Traditionally, water management in a community has been handled via separate methods, technologies and regulations for:
- Household wastewaters (septic systems),
- Storm water removal,
- Water table management,
- Flood control, and
- Erosion and sedimentation control.
Professionals who plan and design septic systems do not typically consider the effects of the septic system used in a subdivision on other water management needs, such as storm water treatment. Rules that regulate the design of septic systems are separate from those that regulate storm water treatment and removal. Likewise, professionals who plan and design storm water treatment systems, or flood control systems, dont address the likely effects on the septic systems installed in the area. The same can be said for the other water management issues listed above.
Therefore, one of the key points of this project is to demonstrate a new method to manage water in a community using a watershed approach. This method is currently being called Integrated Water Designs or IWD. Integrated Water Designs will address water management from all of the water management issues listed above and do so in a coordinated way. This project is expected to break across technology and regulatory barriers that have led to uncoordinated water management in local communities throughout much of the United States. Hence, this is a national demonstration project.
The Integrated Water Designs that will be developed as a part of the project will primarily be land-based technologies. That is, the land will be a critical part of the wastewater (septic system) and storm water treatment systems for protecting water quality. The land, and particularly how it is managed, will also play a role in minimizing water quantity impacts such as flooding, erosion control, and storm water removal. Integrated Water Design concepts can include technology designs for on-site wastewater treatment (septic systems), storm water treatment and removal, drainage of surface water and ground water, flood control, water table management, erosion and sediment control, water supply and agriculture water needs.
The first part of this project is to develop the IWD concepts and then select and design the technologies. A team of land-based technology experts from North Carolina State University, other universities, local and state agencies and other organizations will accomplish this task. The Integrated Water Designs developed by this team will be installed in a demonstration community or subdivision where their performance can be monitored. First, through, the existing baseline water quality conditions and water quantity impacts (e.g. storm water removal, flooding, etc) in the community will be monitored scientifically. Then, the effects of IWDs on water quality and management will be measured.
Existing Conditions
Many rural and urban areas in the Pasquotank River watershed are growing so rapidly that they present technological challenges for maintenance of water quality and protection of the environment. The physical conditions include wet, slowly permeable soils on very wide flat areas that drain to the Albemarle Sound. Water does not move easily or flow rapidly through these soils.
Septic systems are utilized 
throughout much of the rural
and developing areas in the watershed. Because of the flat topography these areas naturally have ground water
close to the ground surface. Soils oftentimes have clayey or silty subsoils
that limit downward movement of water. Therefore, traditional septic systems can not be used in many areas. But
these clayey subsoils are frequently underlain by sandy, more permeable soil
layers that can allow faster water movement through them. Due to these soil
conditions, a unique type of septic system that includes a sand lined trench drainfield is used on many
building lots in the watershed. Sand lined trench systems are installed by
digging out the clayey soil layers and replacing this material with sand that
is brought to the site from another location. Then, the gravel-filled septic system drainfield trenches are installed
on top of the imported sandy fill material. These sand lined trenches are used
together with drainage ditches and/or buried draintubing along the lot
perimeters. The purpose of the drainage system is to improve wastewater
treatment in the soil by controlling the water table. This local drainage
around each lot is then connected to subdivision-wide drainage systems. These
subdivision-wide drainage systems frequently are deep ditches surrounding the
subdivision. The subdivision-wide drainage systems then connect to larger more
regional drainage networks that move the water to swamps, DOT ditches, rivers
or the sound. This drainage network not only controls the water table for the
septic systems to work correctly, but also removes storm water and helps
prevent flooding. Therefore, the drainage network is needed for more than one
reason. One problem is that the deep drainage ditches that all of this water management depends upon frequently fill
in with sediment over time. Both the septic systems and the drainage networks
must be carefully maintained to function effectively. The drainage networks are
also important for agricultural to enhance productivity and water quality.
However, agricultural BMP practices oftentimes utilized controlled drainage
that holds water in the ditches.
Project Overview
One demonstration community will be selected at some location in the Pasquotank River watershed based upon the interests of the homeowners to participate in the project and the potential for IWD technologies to solve an existing, critical water management problem. The project team is currently in the North Meadows subdivision to collect information for developing the project work plan that must be submitted to EPA before the project can start. The subdivision has not been identified as the place where this project will be conducted. However, the project team is looking at whether the North Meadows subdivision might be a good place to use the IWD approach. No demonstration community will be selected until after we can determine that the project has a high likelihood of success at that location and a formal community meeting is held to describe the project fully enough so that the citizens in the community can determine if they want to become the demonstration community for this project.
Once a project work plan has been reviewed and accepted by EPA and a demonstration community selected, then very shallow monitoring wells will be installed. Ground water and surface water samples will be collected and water flow conditions monitored to determine the existing baseline water conditions in the demonstration community. This will be done before the integrated water management designs are installed. The monitoring effort is expected to include assessment and tracking of key water quality pollutants as they move through the ground water. Bacterial source tracking (BST) techniques will be investigated to determine if they can help identify key microbial pollutant sources.
Once the NC State University-led team develops the Integrated Water Design concepts, the technologies selected will be installed under the direction and coordination of the Albemarle Regional Health Services Agency. In addition, more advanced types of septic systems (beyond the sand-lined trench system currently used for wastewater treatment in the watershed) will be evaluated to determine their potential use as IWDs for repair of failing septic systems. Septic system failures can occur as hydraulic surface failures or as ground water contamination failures.
The project involves a substantial partnership between the Albemarle Regional Health Services Agency and North Carolina State University. The Albemarle Agency's management entity and management monitoring programs can provide observation and maintenance of critical water structures and non-structural components of the integrated water designs during the project. The NC State University team can assess water quality improvements resulting from implementation of the integrated designs. They plan to compare ground water and surface water conditions before and after installation of Integrated Water Designs.
The NC State University team, working in partnership with the Pasquotank County Cooperative Extension office and the local Albemarle Agency staff will coordinate technology transfer training in the county. Water management professionals throughout the state will also be trained at the Universitys hands-on training centers that are located throughout the state. New hands-on demonstrations and training materials will be developed to describe the IWD approach to practicing professionals such as soil scientists, planners, technology designers, installers and service providers. The North Carolina Cooperative Extension will lead public educational programming efforts for community decision makers and field practitioners.
This project will take 4 to 5 years to complete due to the need to establish baseline water quality conditions in the demonstration community, develop and install the integrated designs, assess their effectiveness and then provide technology transfer training and education programs to disseminate the results.
Project Team
The demonstration community will be selected and the project implemented by a team led by Mr. Ralph Hollowell and Dr. Mike Hoover. Mr. Hollowell is an Assistant Director and Soil Scientist in the Albemarle Regional Health Services Agency. Dr. Hoover is Professor of Soil Science at North Carolina State University and an Extension Soils Specialist with North Carolina Cooperative Extension. The NC State University project team includes faculty from a number of departments and colleges, including the North Carolina Cooperative Extension.
The Albemarle Regional Health Agency is uniquely qualified to lead this project due to its extensive, unique and forward-looking wastewater management program that extends throughout the entire northeastern corner of North Carolina, covering 11 of the state's 100 counties. This wastewater system management program is an important organization that has been helping to protect the environment in northeastern North Carolina. It is one of the primary reasons that this national demonstration project is being located in this watershed. The agency has the capability to integrate the other aspects of water management such as storm water and flood control into its wastewater management program.
Groups such as the local Soil and Water Conservation District, East Carolina University, North Carolina A&T University, Elizabeth City State University, the UNC Coastal Studies Institute and other organizations also have substantial expertise in water management. Therefore, they will be asked to become involved in this national project and help solve the problems in the demonstration community.
Contact Information
North Carolina State University
Albemarle Regional Health Services
NC Cooperative Extension: Pasquotank County Center