By Tom Bruursema
Is it practical for central treatment facilities to use point-of-use/point-of-entry (POU/POE) water treatment as a means to achieve compliance with the Safe Drinking Water Act (SDWA)?
In light of the recent change to the regulated arsenic standard, dropping the maximum contaminant level (MCL) for drinking water from 50 parts per billion (ppb) to 10 ppb, many now view POU/POE technologies as being not only practical, but quite possibly a necessity.
To facilitate both education and action on this issue, NSF International and the NSF Center for Public Health Education recently held a conference, “Public Water System Compliance Using Point-of-Use and Point-of-Entry Treatment Technologies,” on Feb. 13-14, in Orlando, Fla. More than 120 professionals attended the conference representing a cross-section of the stakeholder community. A total of 16 experts—ranging from state and federal regulatory officials, utilities, consultants and industry representatives—presented on the many aspects of using POU/POE as a compliance tool. This was the second NSF conference in a series targeted at specific risk management issues affecting the POU/POE industry, with the first being the “NSF International and World Health Organization Symposium on HPC Bacteria in Drinking Water – Health Effects?” held in Geneva, Switzerland, April 21-23, 2002.
The U.S. Environmental Protection Agency (USEPA) has been very active over the past year in clarifying regulations relating to the use of POU/POE for compliance, and developing guidelines and funding pilot studies. Several USEPA representatives made presentations including a detailed review of federal regulations relating to the selection and application of products, as directed by the 1996 amendment to the SDWA. They also reviewed the USEPA’s draft document, “Guidance on Implementing a Centrally Managed Point-of-Use and Point-of-Entry Treatment Strategy for Compliance.” As a guidance document, it has no force of law, but does offer clarification on regulations and suggestions for an implementation strategy that complies with the regulations. This document will be key in the future success of this approach, particularly in providing guidance to state regulators. It was announced at the conference that a revision to the guidance document is due out in May.
While we often think in terms of the utilities and the POU/POE industry as being the drivers behind this initiative, the USEPA was quick to point out the importance of the consumers and, more specifically, their veto power. Considering these devices need to be installed and maintained in the home, consumers have ultimate control over the ability to provide treated water. Emphasis was placed on developing consumers’ confidence in advance through proper education. Participation of 100 percent remains a requirement of the SDWA, i.e., all homes and businesses must receive potable water whether by central treatment or POU/POE. Achieving this will be difficult, but more likely obtained through demonstration of an affordable and credible program with limited burden on the consumers. Independent product testing and certification to the ANSI/NSF standards was emphasized as a key element in achieving consumers’ confidence as well as a requirement of the SDWA.
Recognizing the primary benefit of using POU/POE devices as a compliance tool was affordability, the USEPA also reviewed its cost analysis studies. Equipment purchase vs. rental were both analyzed and compared to central treatment, taking into consideration POU/POE installation, maintenance, sampling, pilot demonstration, public education, waste disposal, record keeping and other factors. In the case of POU treatment for arsenic using reverse osmosis (RO), the point of convergence for all three options was approximately 100 households. Below 100, use of POU was more economical and, above that, central treatment was more economically feasible. In comparison to POE, the point of convergence came much earlier at around 25-50 homes due to the added cost of treating all water in the home rather than at a single tap. The comparison of rented vs. purchased equipment showed little difference in the break-even point when averaging cost over time, but clearly has an impact on initial cost to the homeowner. While the break-even point of 100 households for POU treatment may seem to be a limiting factor, the USEPA pointed out that 30 percent of all community water systems affected by the new arsenic rule serve fewer than 100 people.
The state perspective, as presented by representatives of Utah and Illinois, reflected on the added burden to states using POU/POE. As a compliance issue, states are given primacy by USEPA to implement the SDWA. In the case of POU/POE devices, new rules need to be drafted to allow for this option. In consideration of limited state resources, there was a need expressed to develop draft rules states can adopt more easily. The agency is considering a further rule adoption that would complement the existing SDWA while also providing additional assistance to states for simplifying their local adoption of appropriate regulations for the use of POU/POE.
The utility perspective, as presented by the Los Angeles Department of Water and Power (LADWP), included first-hand experience with homeowners and POU devices. Considering that the LADWP has nearly 700,000 connections serving a population of 3.8 million people, use of POU/POE devices would clearly not be a practical option to central treatment. LADWP conducted a customer survey, however, and discovered 53 percent of its customers would be interested in a POU treatment system in the home, if it were provided at cost. Further, LADWP recognized customer satisfaction with taste was a primary factor in the consumers’ perception of “safe water.” Recognizing it will never be able to fully manage aesthetic quality through central treatment, POU devices provided by the utility may offer a means to improve water quality and, therefore, overall customer satisfaction. LADWP also learned consumers wanted enhanced treatment to be an option rather than a requirement, along with other options such as bottled water. LADWP recognizes consumers view the department as having the expertise in water, giving the utility an advantage in providing alternatives such as POU to their customers with added confidence. This is a significant factor in the overall success of such a program.
Using a pilot study, the LADWP learned some of the challenges inherent with home installations. First, it found that equipment vendors and installers vary in how they approach the consumers. Some provided helpful information and education while others offered very little, impacting overall consumers’ confidence and comfort. Second, installation options can vary due to the age of the home, type of plumbing and ease of access. This brings into question the idea one technology can meet a community’s needs. Another finding related to the home environment and the realization utilities cannot control cleanliness of the home. This could impact issues such as proper sample collection.
While recognizing the shortcomings, LADWP voiced optimism POU devices can be used effectively for improving water quality and customer satisfaction. LADWP is updating its website to include information relating to POU including links to other related sites. Long-term considerations include vendor partnerships, rebate programs for those customers who make their own POU purchase, partnerships with consumer groups for enhanced education, and others.
Several individuals representing the POU/POE industry, private consultants and government made presentations on the many treatment technologies available in the marketplace today. The basic message was that POU/POE technologies have been available for several decades, covering a wide range of product types and capabilities. Further, American National Standards and independent product certifications exist for most product types and water-related contaminants, allowing for proper evaluation of materials, structural integrity and contaminant-reduction performance claims. These are important aspects related to government, utility and consumers’ confidence. What remains is an education gap that needs to be addressed. Regulators, utilities and consumers need to become more knowledgeable of the available options, capabilities and critical technology considerations including flow rates, replacement frequencies, waste generation, installation needs and more. A lack of knowledge and information will only reinforce the resistance to POU/POE products as a compliance tool.
NSF provided a detailed review of the available standards that exist today, the role of the American National Standards Institute (ANSI), and the process of achieving product certification. The 1996 amendment to the SDWA specifies use of only those products certified to the ANSI/NSF standards, where available. With nearly 5,000 models certified to NSF standards, it was made clear that there were many vendor and product options available to satisfy the need for use of POU/POE as a compliance tool.
Learning by example
An important element of the conference was an update from those organizations that are actively engaged in piloting the use of POU/POE devices by public water utilities. Three pilots were presented including two funded by the American Water Works Association Research Foundation and one by the USEPA.
Two of the pilots are targeted at POU devices for the treatment of arsenic. The performance of the selected technologies was shown to be acceptable to-date in both cases, demonstrating that the delivery of safe water from a POU installation can be achieved. Treatment technologies included RO, activated alumina, and granular ferric hydroxide. Cost analyses demonstrated a similar result to that of the USEPA, showing a break point between POU and central treatment somewhere under 200 connections, and clearly more cost effective using POU at 80 and fewer.
The third pilot is reviewing the use of POU/POE technologies in a more general scope including but not limited to compliance. Use of these devices in conjunction with all central treatment operations was evaluated, similar to the applications and opportunities identified above by LADWP. Consumers’ acceptance and confidence were again emphasized as major factors, and the advantages that utilities have with achieving customer confidence when introducing new approaches to water treatment. All three pilots are continuing in their investigations and will be publishing final reports later this year.
Future utility POU/POE use
The conference clearly identified some of the difficulties with using POU/POE treatment technologies as compliance tools. Most notable were the following:
- Requirement to treat water remotely; i.e., in the home, leading to reduced confidence in the quality and consistency of treatment;
- Ability of the consumers to drink untreated water simply by using untreated taps;
- Need for development of state regulations governing the acceptance and use of POU/POE devices when used as a compliance tool, and
- A lack of knowledge by the government, utilities and consumers regarding POU/POE technologies.
The above issues, however, were balanced by the benefits, needs and opportunities POU/POE treatment can offer including the following:
- Cost benefits of using POU/POE as a compliance tool for many small communities;
- Ability of utilities to improve upon overall customer satisfaction with their water quality;
- Availability of many certified systems that can deliver treated water meeting the SDWA, and experience of several decades with their use and installation in homes, and
- The speed of implementation to address reduction of contaminants.
Many consumers across the country use supplemental treatment devices in their homes to improve the aesthetic quality of their public water supplies such as the reduction of chlorine and hardness. Further, residential treatment systems have been used for decades to effectively remove both aesthetic and health contaminants in private water supplies. The use of POU/POE devices in the home to reduce health contaminants in public water supplies is only the latest addition to the expanding application of these products. The biggest difference now, however, is the involvement of utilities and the accountability for delivering safe water through home treatment. This brings new challenges and additional concerns. Whether the benefits outweigh the challenges is still not without debate; however, representatives from all stakeholder communities agree that the use of POU/POE by public water utilities has the potential to benefit everyone. It’s a shift in thinking that, in practice, will not come quickly but the momentum has begun.
(For more information on the USEPA’s role efforts, download “Guidance for Implementing a Point-of-Use or Point-of-Entry Treatment Strategy for Compliance with the Safe Drinking Water Act” at http://www.epa.gov/ogwdw000/standard/draftguid_pou_poe.pdf. To download copies of the presentations from the NSF Conference, visit http://www.nsf.org/cphe/cphe_proceedings.html.)
About the author
Tom Bruursema is general manager of NSF International’s drinking water treatment unit testing and certification program. He is a 17-year veteran of NSF and holds a bachelor’s degree in science and a master’s degree in general biology from Eastern Michigan University. He can be reached at (734) 769-5575, (734) 827-7122 (fax) or email: firstname.lastname@example.org