Tuesday, February 05, 2008

TCE and Scottsdale's water: update on last month's contamination incident

The following is a long post, mostly of the 'copy and paste' variety, so let me summarize -

The Miller Road Treatment Facility remains shut down, and the EPA has ordered a full investigation. The EPA has requested a meeting with the Participating Companies (PCs) this week to discuss a number of options, including leaving the MRTF off-line as far as providing drinking water - it would just be a treatment facility aimed at controlling the spreading groundwater contamination plume. Other options include adding redundant systems.

I've copied and pasted where I could, but for some of it, I had to transcribe letters. I apologize for any typos (mostly misspellings) and take responsibility for those. However, there were a number of instances of poor grammar or awkward word choice. Those are the responsibility of the original writers.

If anyone is interested in the original email and attachments, drop a line to me at cpmaz[at]yahoo.com or contact Vicki Rosen at Rosen.Vicki[at]epamail.epa.gov to be added to her mailing list for the NIBW Community Involvement Group.

On to the actual post...

Vicki Rosen, the EPA's Community Involvement Coordinator, sent out an email yesterday regarding January's incident that affected approximately 5000 customers of Arizona American Water.

The message in its entirety (note: I adjusted the formatting and punctuation for readability, but made no content changes in copying the note or its attachments - except for editing out a couple of phone numbers) -

Hello CIG members,

I wanted to give you a quick update related to the failures at theMiller Road Treatment Facility (MRTF).

First, I've attached at the bottom of this page the Incident Report on the January failure which EPAreceived from the Participating Companies on January 23 and a letter EPA sent to Motorola on February 1. Second, I want to reiterate a few important points:

EPA has ordered a complete investigation into the causes of the incidents.
EPA has ordered a thorough evaluation of all options to ensure that it never happens again.
The treatment plant will remain shut down until EPA, the State and the County are satisfied it will operate safely.
Fines and penalties under the Consent Decree and Safe Drinking Water Act are likely down the road, but for now our highest priority is to ensure clean drinking water to the public.
EPA will review notification procedures that are in place to determine if they are adequate or need to be revised.
Below is information the Arizona American Water Company sent to its customers regarding the exposure the public may have received during the most recent event:

U.S. EPA advises that due to the short term duration of the exposure, the public should not experience and adverse health [sic] affects from tap water that was consumed in the 24 hour period prior to notification and shutting down the system. This would apply to both children and adults consuming up to 6 liters of water per day when TCE levels may have exceeded federal drinking water standards.
Nonetheless, residents with concerns regarding their particular health condition should consult their medical provider. The EPA has shared the sampling data on which this information is based with the ADEQ and Maricopa County.

I will be back in touch with you all as I have more information. In addition, I'm developing a fact sheet for the entire NIBW mailing liston the incident and what's being done about it.



(See attached file: Transmittal_J_Watt.012308.pdf)
(See attached file: MRTF.pdf)

The text of the letter from the NIBW participating companies -

January 23, 2008

Jamey Watt
Region IX (SFD-8-2)
75 Hawthorne Street
San Francisco, CA 94105-3901

Re: Discharge of Groundwater Exceeding Treatment Standards from Miller
Road Treatment Facility

Dear Mr. Watt:

This letter is formal notification that a malfunction at Miller Road Treatment Facility (MRTF) resulted in discharge of groundwater to the Paradise Valley Arsenic Treatment Facility (PVARF) that exceeded the treatment standard of 5 ug/l for trichloroethene (TCE). The equipment malfunction occurred on Tower 3 while treating groundwater extracted from well PCX-1. This notification complies with the seven-day written response requirement as specified in the North Indian Bend Wash Superfund Site Sitewide Operation and Maintenance Plan, dated June 15, 2006.

The blower on Tower 3 shutdown for unknown reasons at approximately 2:30 p.m. on Tuesday, January 15 after the operator had left MRTF for the day. The situation was detected on Wednesday, January 16 at approximately 6:30 a.m. when the operator returned to MRTF for his next shift. At approximately 6:45 a.m., the operator reset the control command and restarted the blower. The treatment train was shutdown at approximately 9:30 a.m. Arizona American Water notified the North Indian Bend Wash Participating Companies of the incident at approximately 10:00 a.m. Remedial Project Managers of Environmental Protection Agency and Arizona Department of Environmental Quality along with City of Scottsdale Water Department staff were contacted and verbally notified of the water quality incident on the same day.

Samples of water were immediately collected by AAW personnel at the MRTF and PVARF and submitted to Transwest Geochem, Inc. for rush analysis of NIBW chemicals of concern (COCs). Laboratory analysis of a sample collected from the MRTF effluent at approximately 9:00 a.m. on January 16 indicated a concentration of TCE at 15 Eg/l. A sample collected at approximately the same time at PVARF had a TCE concentration of 22 Eg/l.

Arizona American Water (AAW) has collected additional samples at PVARF and the Paradise Valley drinking water system. Those data have been submitted to and reviewed by EPA, Arizona Department of Environmental Quality, and Maricopa County. AAW has performed extensive response actions and is in communication with their customers and the appropriate agencies regarding the incident.

Well PCX-1 and Tower 3 had been operating continuously without incident since December 14, 2007 following extensive start-up testing. An aggressive monitoring program since mid-December indicated that treated water from MRTF has met treatment standards for the NIBW COCs.

The MRTF control system includes five interlocks associated with blower operation. These interlocks are low air flow rate, high and low air pressure, blower high vibration, and blower status. Initial investigation into the incident has revealed that moisture in the tubing from the air flow rate element to the transmitter prevented the measurement to drop below the interlock set-point when the blower shutdown.

The pressure monitoring device had been replaced, but not fully integrated into the control system and therefore the interlock was not active. Failure of the control system to recognize that the blower had shutdown based on status is unclear at this time.

The MRTF control system also includes redundant operator notifications in the event of certain alarms and shutdowns. Neither of the notification systems responded to the blower shutdown and no notifications were made to alert the operator of the equipment malfunction. Further investigation and testing will be required to determine the exact reason why the blower shutdown in the first place; why the blower status parameter did not initiate an alarm and treatment train shutdown; and why the redundant operator notification systems did not work.

As you know, the MRTF will be under going a non-routine preventative maintenance rehabilitation beginning in February 2008. The rehabilitation activities at MRTF include replacing the packing in each tower and upgrades to instrumentation. Based on the instrumentation and control system malfunctions associated with this incident, the NIBW Participating Companies will also ensure that there is a detailed review and validation of the MRTF control system during the rehabilitation project and that upgrades recommended as a result of this review are implemented.

If you have any questions, please feel free to call me.

Very truly yours,

Dennis H. Shirley, P.G.

The letter from the EPA to Motorola -

February 1, 2008

Mr. Michael Loch
Corporate Director, EHS Strategic Initiatives
Motorola Inc.
1303 East Algonquin Road, Mail Drop: 3rd floor
Schaumburg, Illinois 60196

Subject: Miller Road Treatment Facility, Indian Bend Wash Superfund Site, Phoenix, Arizona

Dear Mr. Loch:

The purpose of this letter is to convey the Environmental Protection Agency's (EPA's) concerns regarding the October 2007 and January 2008 incidents at the Indian Bend Wash Miller Road Treatment Facility (MRTF) which have resulted in discharges of of groundwater in exceedence of the treatment standard of 5 ug/l for trichloroethene (TCE). These continued failures at the MRTF are unacceptable to EPA. We expect a full investigation into both incidents and an evaluation of a full range of options to ensure that failures never happen again.

While we are evaluating our enforcement options, our highest priority is to ensure that safe drinking water is provided to the residents of Scottsdale and Paradise Valley. Therefore, pursuant to the Consent Decree (CD), Motorola on behalf of the Participating Companies (PCs) may not restart the treatment plant until all levels of government are confident that the system will provide clean drinking water and approval is formally granted by EPA, the State, and Maricopa County.

The first failure at the plant, which occurred during a planned maintenance event sometime between October 9, 2007 and October 17, 2007, resulted in incomplete remediation of the the groundwater at the MRTF. The effluent water from MRTF was sampled on October 15, 2007 and the result was 9.3 ug/l of TCE. This water then traveled to the Paradise Valley Arsenic Removal Facility (PVARF) where it was blended with water from other sources at a ratio of approximately 1 to 3 before entering the distribution system. Based on this blending, we project that the water served to the public was below the 5 ug/l MCL for TCE.

Upon learning of this plant failure, EPA and Arizona Department of Environment Quality (ADEQ) began an investigation of the incident which included meeting with the PCs and Arizona American Water on December 17, 2007. During our meeting, Motorola could not fully explain what happened at the Plant during this incident but they assured us that this was an isolated incident resulting from maintenance work being conducted at the plant. We were told that MRTF was to undergo a full rehabilitation that would result in performance improvements. EPA sent a letter to the PCs on December 14, 2007 requesting additional information needed to complete our assessment of the incident. In this December 2007 letter, we outlined short-term and long-term procedural requirements for MRTF to ensure that this type of incident did not reoccur during maintenance events. The PCs responded in a January 4, 2008 letter but did not commit to any procedural or equipment modification as requested. It is unclear at this time if the procedures could have prevented the second incident from occurring because of the uncertainties surrounding both incidents. However, we will conduct a full evaluation of all of the possible interim measures and long-term options taking into account information learned from both failures at the Plant.

A second malfunction at the plant occurred on January 15, 2008. The PCs contacted EPA upon discovery of the equipment malfunction and provided formal notification in a letter dated January 23, 2008. The equipment malfunction occurred on Tower 3 which is used to treat groundwater from PCX-1. The most recent sampling results from PCX1 show TCE concentrations at approximately 70 ug/l. No operator was present at the Plant when the malfunction occurred and the notification systems and alarms failed to function properly. As a result, water from PCX-1 was discharged from MRTF without treatment from 2:30 pm on January 15, 2008 until 6:30 am on January 16, 2008 when the operator returned to the Plant. No samples were collected from the MRTF or PVARF effluents when the malfunction was discovered at 6:30 am. The operator reset the control command and restarted the blower at 6:45 am. The system operated properly from 6:45 am until it was shut down entirely at 9:30 am. The MRTF effluent was sampled at 9:30 am, several hours after the system had been restarted, and TCE was detected at 15 ug/l. The PVARF effluent was sampled at the same time and TCE was detected at 22 ug/l. The PCs indicated that they, along with Arizona American Water, did examine flow conditions during the 16 hour period of the malfunction and based on their calculations believe that the 22 ug/l TCE detected in the PVARF effluent is likely representative of the TCE concentration that entered the drinking water system.

It is the responsibility and legal obligation of the PCs to ensure that the groundwater remedy selected at the NIBW site meets the water quality standards established in the Record of Decision. At this time, the EPA is not confident that the MRTF will completely remediate the groundwater as currently designed or that procedural changes can be put in place sufficient to ensure that a similar incident does not occur in the future. At the same time, both EPA and the State are concerned that if the system remains off too long the plume may spread and impact surrounding wells.

We request a meeting between EPA, ADEQ, and the PCs the week of February 4, 2008 to discuss implementation of interim measures necessary to capture the plume and the process of evaluating the long term options. Interim measures would involve pumping and treating the contaminated groundwater, but not yet serving the treated groundwater as drinking water. Interim measures will give us the time to thoroughly evaluate long term options.

Finally, we request that the PCs respond to the attachment by Feb 22, 2008. If you have any questions regarding this letter, please contact Sheryl Bilbrey at (xxx) xxx - xxxx or myself at (xxx) xxx - xxxx.


Keith Takata
Director, Superfund Division

Attachment to EPA's letter -

MRTF Attachment
Responses to be submitted to EPA by Feb 22, 2008.

Concurrent with developing responses to this attachment, EPA and the State request a meeting with the PCs, the week of February 4, 2008 to discuss interim measures to pump and treat the contaminated groundwater but not yet serve the treated groundwater as drinking water. While the interim measures are in place, we will have the time to thoroughly sidcuss and carefully decide long term options as described in the last section of this attachment.

The January 23, 2008 letter provides some information regarding the plant failure, however there is addition information required under Section 8.2 of the Operation and Maintenance (O&M) plan that was not included. Specifically, information regarding the person who discovered the malfunction must be provided. We also request that all electronic data from the plant be retained.

Compliance requirements for Consideration as part of the Overall Comprehensive Evaluation of the MRTF for Long Term Operation

EPA formally issued a response to the October 15, 2007 incident on December 14, 2007 outlining short-term and long-term compliance requirements associated with the overall operation of the MRTF, "start-up" sampling requirements, bi-weekly sampling, and notification requirements. Attachment 2 of the letter also included short term requirements for a detailed engineering evaluation of the Tower 2.

The recent failure of Tower 3 warrants a revision to this response letter to include a detailed engineering evaluation on the entire MRTF plant and associated groundwater extraction wells. As a result, the PCs must implement the following requirements in addition to the requirements outlined in the December 14, 2007 response letter to address the long term operation of MRTF. This includes at a minimum, addressing the following key issues:

* A detailed engineering evaluation of Towers 1, 2, and 3. This evaluation should be based on the original design of the MRTF as a basis of comparison. This evaluation should also include the extraction wells and their associated mechanical, electrical, instrumentation, and control systems.

* Provide a detailed work plan for an engineering evaluation of the entire MRTF facility and extraction well systems. This work plan should include a comprehensive and rigorous evaluation and assessment of key equipment, instrumentation and control systems similar in scope to an initial plant start up after construction (e.g. each instrumentation element and control loop is tested individually as well as part of an overall system). As part of the detailed engineering evaluation, trend analysis for all the measured operating and status parameters on the PLC should be done to better understand what caused the system components to fail and what repairs are necessary.

The work plan should also include review and reassessment of all operation and maintenance plans and associated procedures and protocols to validate that operation and maintenance procedures and functions are being properly implemented. Perform all necessary maintenance on Towers 1, 2, and 3 and extraction wells to reflect original design specifications. We suggest the following procedures should be incorporated into the operation and maintenance plan: 1) conduct monthly inspections of these Towers and extraction well systems to check compliance with operational and maintenance plan requirements. Provide a summary report of these observations. Inspections should include verifying alarm conditions and operational response for a non-compliant condition, 2) continue bi-weekly sampling at each of the Tower effluents for a minimum period of 30 days after each of the Towers is compliant with its efficacy. During start-up of each Tower, daily samples with fast turn-around-time should be considered at least for the first 5 days of operation, then switch to bi-weekly sampling as discussed above.

Evaluation of Remedy

Prior to MRTF shutdown, the treated water was discharged to the Paradise Valley Arsenic Removal Facility (PVARF) to be further discharged to either the drinking water supply or the canal depending upon the compliance requirements at the PVARF. We have requested an immediate discussion of interim measures we believe these additional long-term options must also be evaluated:

* Re-injection: Re-inject water back into the aquifer after it is treated at the MRTF. This option would require installation of new injection wells.

* Discharge to Canal: Discharge all treated water at the MRTF to the canal at the PVARF indefinitely.

* Operate More Towers at Reduced Capacity: Operate at least two towers at approximately half capacity each instead of just one tower at near full capacity. In this scenario, if one system were to fail, the effluent contaminant exceedance of the downstream composite water (one-half treated + one-half not treated) would be reduced significantly by about 50 percent.

* Redundant Treatment: Reconfigure the plant plumbing to put two towers in series and use the second tower as a redundant treatment to the first tower. Both towers would have to fail in order to cause a release of untreated water. This alternative would be in addition to the recommended compliance requirements noted above.

* Secondary Treatment: Use Liquid Granular Activated Carbon (LGAC) to treat the groundwater after the air strippers to remove any remaining TCE. This system will serve as a redundant system after the air strippers.

* Continuous VOC Monitoring: Installation of a VOC monitoring sensor to monitor TCE concentrations at a higher sampling frequency. This option would simply detect any TCE exceedances in the effluent of the air strippers. If a TCE exceedance is encountered, then interlocks connecting to the sensor would be programmed to shut the entire system down.

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