Steven Paquette has been appointed president of the U.S. water and environment business unit at WSP | Parsons Brinckerhoff, a global...
As rural, urban fringe and suburban populations increase in all regions of the country, those residents place increasing demands on available water resources. The population of the U.S. is expected to increase significantly in the next 25 years and each of these residents will expect a safe and reliable source of water and a safe and effective wastewater treatment system. Both of these elements of infrastructure must be sustained through time and this will require adequate technical, managerial, and financial capacities in the management systems developed to address the water and wastewater infrastructure.
Options available to manage wastewater are reasonably well known. They consist of a central collection and treatment facility of an onsite wastewater solution. Increasingly, the onsite and decentralized wastewater solution is receiving renewed interest as a permanent solution. Onsite and decentralized technologies are available to achieve very stringent performance levels—levels that mimic the most stringent produced in large, centralized infrastructure.
To achieve these stringent levels:
Demands on the finite supply of water will grow, and one mechanism available to address this demand is through comprehensive recycle and reuse programs. These comprehensive approaches will be required to satisfy the demands placed on resources. Safe and reliable water reuse efforts will be necessary to sustain populations. The real costs associated with failure to recycle and reuse valuable water resources result in the discharge of billions of gallons a day to surface streams, increases in consumptive uses for water, and a general failure to realize the true value of water as a vital resource.
Several communities in the U.S. have developed and implemented comprehensive reuse efforts and these incorporate the concepts promoted by the EPA through the onsite and decentralized program into a managed water resource effort. Communities in the Atlanta, Raleigh-Durham, and Charlotte, N.C., areas have developed these programs to satisfy growing demands for available water supplies and as alternatives to wastewater discharges into sensitive water-bodies.
When properly developed and implemented, reuse programs have been demonstrated as effective in extending available water resources and reducing pollutant discharge to surface waters without creating known risks to public health or environmental quality.
The development of reuse programs as integral to onsite and decentralized efforts will require regulatory programs that support the reuse of reclaimed water, the development of reliable treatment and monitoring systems, and a cadre of operators skilled in inspecting, maintaining, repairing, monitoring and managing treatment and dispersal systems.
Wastewater reuse is here and is incorporated into comprehensive water management efforts. Reuse has been a common practice for generations but only recently has it received the attention necessary to sustain it as an element of the onsite and decentralized wastewater industry as a permanent element of the overall infrastructure. Equipment reliability, operator training and certification, improvements in regulatory programs and demand for reclaimed water are each driving the industry to the recognition of recycle and reuse as a component of the industry. Reuse programs promote many benefits, but not without associated risk. The question then becomes one of managing the risk and through comprehensive management efforts, risk can be managed adequately.
The challenge we as professionals face is to assure the design and operation of recycle-reuse systems is reliable and adequate redundancies are incorporated into systems; the operation and maintenance is satisfactory and performed by trained competent service providers; the reporting is adequate and meets the needs of the regulatory agency; and the public, and site management is adequate to protect public health and environmental quality.
Incorporation of recycle and reuse into water management efforts through the decentralized effort offers communities tremendous opportunity to conserve valuable resources at or near the point of generation, an opportunity to protect local tax base and assets, and an opportunity to protect investment.
Community leaders are party to those decisions that result in a wastewater solution. As communities rely more heavily on performance–based solutions to wastewater management because of stringent environmental or health requirements, management systems must emerge to protect the community investment and preserve the value of the community. The vision of the EPA and other responsible regulatory agencies assures the long term and sustainable management of infrastructure.
A more complex treatment system, such as a surface discharging aerobic system with filtration and disinfection, will require routine monitoring and attention from a professional technician to retain its potential as an effective wastewater treatment system, and requires, therefore, a higher level of management to accommodate this requirement.
Refer to the EPA Onsite Design Manual (EPA, 2003) for guidance on performance and management requirements for onsite technologies.
EPA recommends Model Program 1, System Inventory & Awareness of Maintenance Needs, as a minimum level of management. Model Program 1 represents the recommended management needs for a program where conventional onsite systems, owned and operated by individual homeowners, are sited in areas of low environmental sensitivity, (i.e., no site or soil restrictions such as drinking water wells in close proximity or a high groundwater table). This type of wastewater treatment system is typically not adequately maintained, either because the homeowner tends to ignore even the most basic maintenance requirements or is uninformed as to what is required.
Also, the local regulatory agency is often not aware of the location of all systems within its service area. Model Program 1 is intended to raise the local regulatory agency’s awareness of the location of systems, raise homeowners’ awareness of basic system needs and ensure homeowners meet the system's basic needs. This Program is also necessary as a starting point for communities to have basic data that will allow them to make determinations if higher management levels are necessary. In the Albemarle (N.C.) Regional District this is being accomplished for a fee of $50 per visit.
Model Program 1 also addresses conventional onsite systems, most commonly incorporated into existing programs and representing the vast majority of systems currently in use. However, overall management of these systems is not adequate. Implementation of Model Program 1 will not only raise the quality of management of the typical onsite system but also will establish program elements to identify and deal with circumstances requiring even higher levels of management. A planning area may, for instance, have conditions where there are varying levels of environmental sensitivity. A higher level model, more appropriate for areas with higher sensitivities, can be incorporated into the overall management program to customize system management to the needs of the community or service area.
It is important that the management program be sufficient to adequately manage the full range of environmental conditions. For example, Model Program 3 might be selected for the more sensitive areas such as those along a lakefront or estuary, that have shown to have poor water quality, but a lower level model would still be appropriate for conventional systems in areas that are not as sensitive.
EPA recommends Model Program 2, Management Through Maintenance Contracts, where sites with limiting conditions, such as small lot sizes, or restrictive soil conditions (i.e., slowly permeable soils, shallow soils with limited treatment capacity or high ground water table) are encountered in a small portion of a community. These limiting conditions require improved effluent dispersal to the soil or additional treatment units such as media filters or aerobic treatment units, and are typically operated through contract with equipment vendors. Model Program 2, therefore, sets higher expectations for a regulatory program and for educating homeowners.
EPA recommends Model Program 3, Management Through Operating Permits, for situations where the receiving environment indicates a need for advanced levels of treatment, such as an unconfined aquifer used as a drinking water supply or a fish spawning area. Model Program 3, consistent with the increasing risk, recommends setting measurable performance standards and ensuring compliance by issuing renewable operating permits which indicate specific performance criteria to be achieved. The regulatory agency monitors these systems for compliance with the performance criteria. Performance-based management programs are operating for fees of $100.00 to $150.00 per visit.
EPA recommends Model Program 4, Responsible Management Entity (RME) Operation & Maintenance, where engineered designs, such as aerobic treatment units, are required to overcome site, soil or environmental conditions that are not conducive to conventional or alternative onsite technology. Frequent monitoring and maintenance is needed in these situations. Model Program 4 recommends that operation and maintenance be provided by a public/private RME that is responsible for system performance to ensure the maintenance needs are met.
This program is operating in New Mexico at a cost of approximately $20.00/month.
Model Program 5, RME Ownership & Management, represents the management needs of a more complex program where a very high level of control is required due to public health or environmental concerns or use of complex technologies. Model Program 5 includes the public/private RME as the designated management entity that both owns and operates the onsite systems in a manner analogous to a publicly or privately owned wastewater utility. In this level of management the utility maintains total control of all aspects of management, not just operation and maintenance. This program level operates in both the private utility model and the public utility model. The Tennessee Onsite Utility Co., charges at a rate of approximately $35.00/month while the Shannon City Utility provides water and sewer for approximately $38.00/month