Home Water Treatment Devices - Point of Entry and Point of Use Drinking Water Treatment

POE and POU Information for Homeowners and Public Water Suppliers

A Point of Use (POU) device is a treatment device installed on a single faucet or spigot used for the purpose of reducing contaminants in drinking water at that one tap.  POU devices can sit on the counter, attach to the faucet, or be installed under the sink. A Point of Entry (POE) device is any unit installed to treat the water entering a house or building for the purpose of treating water distributed throughout the entire house or building. POE and POU devices are sometimes used by homeowners to enhance the aesthetic quality (taste, color and odor) of drinking water supplied by a local public drinking water system. In other cases they are installed by private well owners or Public Water Suppliers to meet drinking water quality standards.

Home Water Treatment Devices

Information for Homeowners

Home Water Treatment Might Not Be the Best Option for Everyone
It can be difficult to determine whether you need a water treatment unit in your home or what type of unit would be best for you. Residents of Massachusetts who receive their water from a Public Water Supplier (PWS) have drinking water that typically does not need treatment for health protection. Your PWS must meet all the requirements of the Safe Drinking Water Act and Massachusetts Drinking Water requirements and must supply you with an Annual Consumer Confidence Report to provide you with information regarding the quality of your water. For contact information for your Public Water Supplier see public water suppliers contact list. If you receive your water from a PWS, home water treatment units or use of alternative water would only be needed in cases where a PWS in noncompliance implements actions to come back into compliance or to improve the physical qualities of water - the taste, color, or odor.

If you have a private well and the drinking water has a contaminant that might make you or a family member ill, it is best to remove the contamination source or replace the unsafe water supply with a safe water supply. Home water treatment units may be used to lower health-related contaminants, but care must be taken to identify and use an effective system and to maintain it. Bottled water can be another alternative. Private wells are regulated by local Boards of Health. For MassDEP guidance on private wells see Private Wells.

Selecting and Maintaining a Home Water Treatment Unit
You may want to get your water tested first to determine what, if any, contaminants are present. If you get your water tested, you should use a Massachusetts certified lab. See Find a MassDEP Certified Lab for a list of certified labs. For some contaminants, EPA approved labs may also be available.

No single treatment process can remove all substances in water. If you decide to install a home water treatment unit, the unit (or units) you choose should be certified by NSF, UL, Water Quality Association (WQA), CSA Group or IAPMO R&T, Inc. and specifically labeled to reduce or remove the contaminant you are concerned about.  If there are several substances you want removed from your water, you may need to combine several treatment processes into one system. For a list of certified devices, search NSF Certified Drinking Water Treatment Units, Water Filters. For links to certification bodies:

You should continue to test your drinking water after you install a treatment unit because there is often no way to know if a treatment system has failed. All home water treatment units require regular maintenance to work properly. Regular maintenance can include changing filters, disinfecting the unit, or cleaning scale buildup. Home water treatment units that are not properly maintained will begin to lose their effectiveness over time. In some cases, unmaintained units can make quality worse.

Lead in Drinking Water
If you are concerned that there may be lead in your drinking water see Is there lead in my tap water?

The USEPA has published a guide to help in finding a home water treatment device that will remove lead. See Consumer Tool for Identifying POU Drinking Water Filters Certified to Reduce Lead.

PFAS in Drinking Water
If you are concerned that there may be PFAS in your drinking water, see MassDEP Fact Sheet - PFAS in Drinking Water: Questions and Answers for Consumers.

Point of Use (POU) and Point of Entry (POE) treatment devices are not specifically designed to meet Massachusetts’ or federal drinking water standards for PFAS.  Any treatment device you use should be certified to meet “NSF/ANSI 53” or “NSF/ANSI 58” standards.  Although such certification documents that a treatment device can remove PFAS, it's important to note that the current certification standards for PFAS filters (as of April 2024) do not yet indicate that a filter will remove PFAS down to the levels EPA has now set for a drinking water standard. EPA is working with standard-setting bodies to update their filter certifications to match EPA’s new requirements. If you chose to install a treatment device, you should check to see if the manufacturer has independently verifiable PFAS monitoring results demonstrating that the device can reduce PFAS below the MassDEP and EPA drinking water standards. See more detailed information on POU/POE treatment systems in the Private Well Factsheet.

Creating a New Public Water Supplier by Installation of a POE Device
In some situations the installation of a Point of Entry (POE) drinking water treatment unit into a building would be regulated by MassDEP. If you are installing a POE device to treat water entering a building that regularly serves an average of at least 25 individuals daily at least 60 days of the year, the installation may create a consecutive PWS that would be regulated by MassDEP; see the tab on Water Suppliers if this applies to you.

Information for Public Water Suppliers

Existing Public Water Suppliers (PWS)
Existing Public Water Suppliers may be considering the installation of Point of Use or Point of Entry devices in their customers' homes in order to meet Massachusetts Drinking Water Quality Standards versus installing a centralized water treatment system. POU and POE treatment devices rely on many of the same treatment technologies that have been used in central treatment plants. However, while central treatment plants treat all water distributed to consumers to the same level, POU and POE treatment devices are designed to treat only a portion of the total flow.

Not all types of contaminants can be treated with a POU or POE device. See EPA's guidance document with recommendation on how to select, install, operate, maintain, and monitor this equipment. The guidance document also outlines the technical, operational, and managerial issues involved in implementing a POU or POE treatment strategy. See Additional Resources Point-of-Use or Point-of-Entry Treatment Options for Small Drinking Water Systems.

Installation of POE or POU devices in order to meet Massachusetts Drinking Water Standards (reduce contaminants to less than the maximum contaminant level or action level and/or satisfy a treatment technique requirement), is regulated by MassDEP. See Additional Resources Self Guide for Point-of-Use and Point-of-Entry Treatment Devices to get started on the process of permitting and approval for use.

Creation of a New PWS by the Installation of POU/POE Devices
For owners of buildings considering the installation of POE/POU devices, MassDEP does not regulate POE/POU devices unless the installation would create a consecutive Public Water Supplier (PWS). If the device treats all the water entering the building (a POE device) and regularly serves an average of at least 25 individuals daily at least 60 days of the year, the installation would create a PWS. If the POE device is being used to address aesthetic concerns only, it is not regulated by MassDEP as long as the owner meets all the requirements of the MassDEP Drinking Water Regulations, 310 CMR 22.23 (6) (see Additional Resources below). If the POE device is being used to meet Massachusetts Drinking Water Quality Standards (reduce contaminants to less than the maximum contaminant level or action level and/or satisfy a treatment technique requirement) the owner would become a PWS and would be regulated as such by MassDEP.

Schools that are installing POU treatment at bubblers, water fountains and kitchen sinks in order to remove lead are not considered consecutive PWS. Drinking water sitting stagnant in plumbing overnight can leach lead from the pipes and fixtures in a school containing lead (such as older brass fixtures). The long-term solution for all schools in Massachusetts is to replace the plumbing that contains lead.

New Technology Approvals for POE/POU Devices/Systems (BRP WS31)
POE/POU devices need a new technology approval when used by a Public Water Supplier to meet Massachusetts Drinking Water Quality Standards and comply with 310 CMR 22.23. See Additional Resources - Technology Approvals for POE/POU Devices/Systems for a list of new technologies for POE/POU devices or systems that have been approved for use by Public Water Suppliers in Massachusetts. The inclusion of a technology on this list does not constitute MassDEP endorsement of the product. Some products may no longer be available.

f you are interested in obtaining approval for a New Technology for a POE/POU treatment system that is not currently on the MassDEP list, visit the MassDEP website at https://www.mass.gov/how-to/ws-31-new-technology-vending-machines-poupoe-devices.

Additional Permit Requirements when a PWS Plans to Use POU/POE Devices to Remove a Contaminant that Exceeds a Massachusetts Maximum Contaminant Level (MMCL) or Other Drinking Water Standard Specified by MassDEP
In addition to the requirement to use a POU/POE treatment device that has received MassDEP new technology approval, you will be required to submit a permit application to modify an existing PWS by installing POU/POE devices.  See the Self Guide for Point-of-Use and Point-of-Entry Treatment Devices for more information and links to the applicable permit application forms.

What are the Implications for a PWS Regarding Existing POU/POE Treatment Devices if the PWS has an MMCL Violation?
As part of Public Notice (PN) and/or Public Education (PE) requirements that result from an MMCL violation, a PWS must inform its customers whether or not  existing POU/POE devices that their customers may have installed have been evaluated by the PWS to determine their efficacy to remove the contaminant(s) of concern.  The PN and/or PE requirements for a PWS with an MMCL violation will be different for a PWS that is, or had been, actively promoting the use of POU/POE devices to address aesthetic water quality issues.

Your customers who had previously installed POU/POE devices to treat for aesthetic purposes may have non-compliant wastewater discharge issues associated with those devices due to the MMCL violation event.  See the section below regarding wastewater disposal for more details.

Additional Resources

Wastewater Disposal from POU/POE Devices (for both Homeowners and Public Water Suppliers)

Before finalizing your choice of POU/POE treatment device make sure that you have an acceptable and approvable disposal option for any wastewater that may be generated by that device. 

Discharge to Municipal Sewer System
Discharge to a municipal sewer system is potentially an option, provided that the local sewer authority approves of the discharge. 

Discharge to Underground Injection Control (UIC) Well
On-site discharge to a registered Underground Injection Control (UIC) well is only an option if nothing in the wastewater exceeds any Massachusetts Contingency Plan (MCP) Reportable Concentration Limit (RCL) or any health-based Massachusetts Maximum Contaminant Level (MMCL) for Public Drinking Water with the exception of sodium and manganese and the limited exceptions for treating arsenic and radiologicals discussed below.

There are limited exceptions for treatment devices that are used to remove naturally occurring arsenic and radiologicals and they are handled on a case-by-case basis (see Arsenic & Uranium Bedrock Well Study: Arsenic &  Uranium FAQ). However, under no circumstance may spent regeneration brine solution from an ion exchange system designed to remove arsenic or radiologicals discharge to a UIC well.

The discharge to a dry well (or any other subsurface infiltration structure) requires the submittal of a MassDEP Underground Injection Control (UIC) registration application and MassDEP approval, with the exception of parcels of land that are only used for a one-unit residence.  See MassDEP DWP UIC Program for details.

Discharge under a Groundwater Discharge Permit
A Groundwater Discharge Permit would be required for on-site wastewater discharge if it would not be eligible to obtain MassDEP approval for a UIC Registration application due to the contaminant concentrations in the wastewater.  This option is probably cost prohibitive due to the following:

  • installation of additional wastewater treatment device(s) to remove the contaminant from the POU/POE wastewater prior to on-site discharge and,
  • installation of upgradient and downgradient monitoring wells, and
  • routine monitoring requirements of the contaminant concentrations in the wastewater and in the upgradient and downgradient monitoring wells and,
  • operation by a MassDEP Certified Wastewater Treatment Plant Operator.

Temporary Storage of Wastewater in an Industrial Wastewater Holding Tank (IWHT)
If discharge to a municipal sewer system or UIC well is not an option and the Groundwater Discharge permitting option is cost prohibitive, then your only remaining option may be to install an onsite Industrial Wastewater Holding Tank (IWHT) and have it periodically pumped out and hauled by a licensed hauler to a facility that is authorized to treat the wastewater.  However, PWS should be aware that due to safety concerns, MassDEP Drinking Water Program (DWP) is unlikely to approve of the use of an IWHT at your customers’ properties.  Therefore, if you are a PWS and the use of an IWHT is the only option available for the treatment device that you are considering, you should seek an alternative treatment option that doesn’t generate water purification backwash with concentrations above an MCP RCL or a Drinking Water MMCL.  The use of an IWHT would require the filing of a WP 56: Industrial Wastewater Holding Tank Compliance Certification form for each parcel on which an IWHT is installed.

Discharge to Title 5 Septic System is Prohibited
You should be aware that Title 5 regulations, 310 CMR 15, specifically state that “backwash of water purification or filtration devices shall not be discharged to an on-site [Title 5] system.”  Discharge to a Title 5 system is prohibited whether or not the wastewater exceeds any MCP RCL or DWP MMCL.

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