# Presentation: 666932

## Point-of-Use and Point-of-EntryJanet CherryThe Cadmus Group, Inc.

## Point-of-Use (POU) Treatment

**Notes:**
A point-of-use (POU) device will treat the water at the tap where the device is installed.  For instance, the POU device is typically installed under the kitchen sink and will treat a side stream of water from the cold water line.  A separate faucet is typically installed to dispense the treated POU water. 

## Point-of-Entry (POE) Treatment

**Notes:**
A point-of-entry (POE) device treats all water that goes into the home.  A POE device is typically used when the contaminant is volatile in nature, such as VOCs or radon.  Water used for outside purposes, such as lawn watering, is typically not treated. 

## SDWA Requirements

- POU devices:
- EPA cannot list POU as an affordable technology for compliance with an MCL or treatment technique for a microbial contaminant or indicator of a microbial contaminant.
- POU and POE devices:
- Must be controlled and maintained by the PWS.
- Must have mechanical warnings to automatically notify customers of operational problems.
- Where ANSI standards have been issued, only units meeting these standards may be used in a compliance strategy.

## ANSI/NSF Standards

- Standard 44:  Cation Exchange Water Softeners
- Standard 53:  Drinking Water Treatment Units- Health Effects
- Standard 55:  UV Water Treatment Systems
- Standard 58:  RO Drinking Water Treatment Systems

**Notes:**
It is important to note that ANSI/NSF certified devices do not exist for all contaminants.  For instance, only one POU adsorptive media device currently exists for arsenic removal that ANSI/NSF Standard 53 certified.  More should be commercially available since this technology is rapidly developing.

## 40 CFR 141.100

- Language specific to Point-of-Entry devices
- Similar to language in 40 CFR 142.62

**Notes:**
The language in 40 CFR 141.100 is specific to POE devices and does not address the use of POU devices for compliance with NPDWRs.  The POE language in 40 CFR 141.100 is very similar to the language in 40 CFR 142. 62 for POU and POE devices used under a variance or exemption.

## 40 CFR 142.62(h)

- Requirements for PWSs that use POU or POE devices as a condition for obtaining a variance or an exemption from NPDWRs:
- The PWS is responsible for operating and maintaining the devices.
- PWS must obtain the approval of a monitoring plan prior to installation of devices.

## 40 CFR 142.62(h)

- The PWS must apply effective technology under a State-approved plan.  The microbiological safety of the water must be maintained at all times.
- The State must require adequate certification of performance or a rigorous engineering design review of the POU and/or POE devices.
- The design and application of the POU and/or POE devices must consider heterophic bacteria concentrations in water treated with activated carbon.

## 40 CFR 142.62(h)

- The State must be assured that all consumers will be protected.
- In requiring the use of a POE device as a condition for granting an exemption from the treatment requirements for lead and copper, the State must be assured the device will not cause increased corrosion of lead and copper bearing materials located between the device and the tap that could increase contaminant levels at the tap.

## Arsenic Rule

- SSCTs for arsenic removal (for systems serving 10,000 or fewer):
- POU Reverse Osmosis
- POU Activated Alumina

**Notes:**
In the recently promulgated Arsenic Rule, POU RO and activated alumina are listed as small system compliance technologies (SSCTs) in 40 CFR 141. 62.  

## POU Reverse Osmosis

**Notes:**
This picture illustrates a 4-stage POU RO unit that could be installed under the sink.  Many of these exist that are ANSI/NSF Standard 58 certified that can remove arsenic.  This device will create a waste stream that will need to be properly disposed.

## POU Adsorptive Media (NSF Certified)

**Notes:**
Only one device is ANSI/NSF Standard 53 certified for arsenic removal as of August of this year.  This particular device has a sediment prefilter that encases another filter that contains an adsorptive media that removes arsenic, all contained in one vessel.  The adsorptive media is used on a throw-away basis.  No liquid waste stream is generated by this type of device.

## POU Adsorptive Media (Non-NSF Certified)

**Notes:**
This particular device is a typical adsorptive media installation that consists of a particulate pre-filter followed by an adsorptive media vessel that contains either activated alumina, granular ferric hydroxide, or other adsorptive media.  The adsorptive media is used on a throw-away basis.  No liquid waste stream is generated by this device.

## POE Adsorptive Media – Auto Backwash

**Notes:**
This type of POE adsorptive media device is backwashed periodically to remove sediment build-up and increase productivity.  Most ferric adsorptive medias commercially available, such as granular ferric hydroxide, are used on a throw-away basis.  Disposal of the backwash stream needs to be considered.

## POE Anion Exchange – Auto Regeneration

**Notes:**
This POE AX operates very similar to a water softener.  A brine tank that contains salt is used to automatically regenerate the AX resins.  Disposal of the liquid waste needs to be considered.

## POU Case Study- Fallon Air Force Base

- POU RO devices installed to address arsenic
- Device had GAC per-filter, sediment pre-filter, RO, and post GAC filters with storage tank

## POU Case Study- Fallon Air Force Base

- No pilot test conducted- POU RO considered a temporary solution to arsenic MCL until system connected to City of Fallon water
- All units installed and maintained under contract by the vendor
- Installation averaged one hour

## POU Case Study- Fallon Air Force Base

- Maintenance and disinfection performed every 9 months
- Both GAC and sediment pre-filters replaced every 9 months
- RO filters replaced every 27 months
- Units removed 90% of arsenic

## POE Case Study- Lumni Island

- POE AX devices installed to address arsenic
- System required to perform extensive pilot testing (2 studies conducted over 4 years)

## POE Case Study- Lumni Island

- System must have certified operator and operator checks POE devices every 3 months
- Takes samples to verify treatment
- POE devices removing arsenic and meeting the MCL
- Device automatically regenerates and waste sent to the individual septic tank and drainfield
- For compliance purposes, each home is considered individually by the State

## General Information

- EPA is currently finalizing a guidance manual to assist states and systems with implementing a POU or POE treatment strategy
- EPA is also working on a cost document that may assist states and systems with identifying potential costs associated with a POU or POE treatment strategy