January 17, 2006

Mr. W. Calvin Horton, Town Manager
Town of Chapel Hill
405 Martin Luther King Jr. Boulevard
Chapel Hill, NC 27514

Dear Cal:

In accord with the Special Use Permit for the Mason Farm Wastewater Treatment Plant, we are pleased to submit the enclosed annual report on our progress toward our off-site odor elimination goal and in the overall improvements underway at the plant.

The attached report essentially updates the progress report which we submitted at the Town Council’s public forum on November 14, 2005. Please note that the attached report refers to but does not include the Odor Elimination Compliance Monitoring Program which we previously submitted to the Town.

Some key items in the attached report include:

In late November, our contractor completed the installation of new cover structures on our four solids digesters in      accord with the original project schedule as a major step forward in odor elimination.

We will meet with interested customers and other stakeholders on January 31st to discuss planning the odor      study to be done by a consulting firm. Our approach in developing the objectives and scope of the odor study will      be collaborative.

In accord with the Town Council’s resolution adopted on November 14th, we will work with stakeholders to      develop an operational definition of odor elimination, and our quarterly reports to the Town of Chapel Hill and      other local governments will also include updates on odor elimination work at the Mason Farm plant.

We remain committed to working with our customers and the Town to achieve results that will be fully satisfactory to the community. We sincerely hope that this process will prove to be a model example of wastewater odor control with open, effective public participation that benefits all parties.

Sincerely,

Ed Kerwin
Executive Director

C:         OWASA Board of Directors

January 17, 2006

Annual report to the Town of Chapel Hill regarding odor elimination at the Mason Farm Wastewater Treatment Plant

Introduction

This annual report is submitted in accord with conditions in the Special Use Permit as modified by the Town Council on March 1, 2004 for the Mason Farm Wastewater Treatment Plant (WWTP).

The special use permit includes the following requirement: 

Offsite Odor Elimination, Monitoring and Annual Report: That OWASA shall present an annual report to the Town Council regarding progress in meeting their offsite odor elimination goal to report on progress during construction, and to report on maintenance and the continuing efficacy of the program post-construction.  The Town Council may reduce the frequency or end the annual report requirement at such time as it determines reasonable.

Actions and Improvements in 2005

Odor-related improvements

Digester covers: Our contractor completed the installation of new cover structures on the four “solids digesters” at the WWTP in late November, 2005 in accord with our original project timetable. (Our “solids digesters” are tanks where solids separated from wastewater are converted into biosolids for reuse on farms to help grow crops for non-human consumption.)

The first two of the new digester cover structures were installed in 2004. In 2005, the two remaining digesters received new covers and one of the previously installed new covers was repaired in the fall after leaks were found.

We believe the digester cover improvements, which cost about $3.5 million, were a significant step forward in reducing odor releases. The covers were originally installed with a circumferential gap that enabled the covers to slide up and down as needed during biosolids treatment, but the gap also allowed releases of odor.  The new digester covers are fixed and they have a perimeter seal to contain foul air in the digester tanks for transport through pipes for burning as fuel or for disposal.

Left: Part of a fixed digester cover structure including the seal installed to prevent leaks at the perimeter of the cover.

Number of reports of odor releases from the WWTP

The table below shows the number of reports of odor from the WWTP from 2002 through 2005.

Several customers have informally reported to us that odor conditions improved as the installation of digester covers progressed over the last year or so.

However, odor reports from citizens increased in November and December, 2005 due to malfunctions in the system of “gas handling” pipes that carry foul air away from the digesters for use or disposal.

We identified these pipes as an additional odor source in the late fall and are planning to renovate or replace them in 2006.

REPORTS OF ODOR FROM THE MASON FARM WASTEWATER TREATMENT PLANT,
2002-2005

Communications with our neighbors and the Town of Chapel Hill
 
Construction-related notices: In 2005, we sent several notices by paper and/or e-mail to customers in the area around the WWTP to advise them about noisy work, increases in construction traffic and anticipated odor releases related to construction.

Community Meeting: On September 15th we held a community meeting to discuss a draft Odor Elimination Compliance Monitoring Program with our neighbors. We invited more than 700 people to this meeting by e-mail and paper mailings. A summary is attached.

The OWASA Board approved the Compliance Monitoring Plan, with changes reflecting feedback we received from stakeholders, in a public meeting on October 13, 2005.

Town Council’s Public Forum: On November 14th, we made a presentation to the Town Council and the community in a televised public forum on our progress in eliminating odor releases from the WWTP. We reported that completion of the digester cover installations was pending, additional odor elimination work is needed and we will do an odor study beginning in 2006 in consultation with stakeholders. We also presented the Odor Elimination Compliance Monitoring Program.

In accord with the Council’s decisions at the end of the public forum, we will work with stakeholders in the WWTP area to draft an operational definition to clarify the practical meaning of “odor elimination.” We appreciate the recognition by the Town and other stakeholders that perfect odor elimination is not practical although it continues to be our goal.

In addition, we will include updates about the WWTP improvements and odor-related matters, including tabulations of odor reports from the community, in our future quarterly reports to the Towns of Chapel Hill and Carrboro and Orange County.

Upcoming Actions

Next community meeting

We will meet with interested stakeholders to discuss planning the odor study and related matters on Tuesday night, January 31st, 2006 at 7:00 pm in the OWASA Community Room. The primary purpose of this meeting will be to enable citizens to meet and talk with our odor consultant and OWASA staff about what the study should accomplish, how it will be done and how citizens should be involved and informed during the study process.

We want to involve stakeholders at this early stage, before the scope of work for the odor study has been prepared, with the objective of reaching consensus on how it will proceed and what it will provide when complete. At the community meeting, we will also discuss developing an operational definition of odor elimination as a follow up to comments from citizens and the Town Council’s discussion in November.

Gas handling system improvements

As discussed above, we recently identified the pipes that carry foul air away from our solids digesters as an odor source and we plan to rework or replace them in 2006. Design work has begun and it should be complete this winter in preparation for the contracting process.

The work may take 6 to 9 months, depending on the specific scope of work, weather conditions and so forth. Unfortunately, some temporary releases will likely be necessary during the construction.

Plant improvements under contract for completion by 2007

As indicated in previous reports, the odor-related improvements scheduled to be completed at the WWTP by May, 2007 include:

Enclosing the WWTP “headworks,” where wastewater enters the west side of the plant in concrete channels and      goes through preliminary treatment tanks that are now open to the air. When this area is enclosed, the foul air      from it will be treated in our odor scrubber. (Please see Attachment 2 for background information about the      scrubber, which was installed in 2004.)

Installing equipment to remove foam that floats on the surface of wastewater while it is treated biologically in      “aeration basins” to remove phosphorus. The foam can be an odor source.

Covering a new sewage pump station to capture foul air for treatment in the scrubber.

Conclusion

We welcome the opportunity to receive comments and respond to any questions about this report or the Mason Farm Wastewater Treatment Plant improvement project and our odor elimination plans.

We look forward to making further progress in the odor elimination program and continuing our discussions with customers in the area around the Mason Farm Wastewater Treatment Plant and with the Town.

Attachments:

1. Summary of community meeting on September 15, 2005
2. Additional background information

Attachment 1

SUMMARY OF COMMUNITY MEETING

regarding odor elimination at the Mason Farm Wastewater Treatment Plant and
a draft plan for evaluation and monitoring of odor-related improvements

7:00 pm, Thursday, September 15, 2005, in the Community Room,
OWASA Administration Building, 400 Jones Ferry Road, Carrboro

Participants

Barnes Bierck, 3 Hampton Hill Place, Chapel Hill
Sian Kwa, 109 Pine Lane, Chapel Hill
Peg Parker, 1010 Highland Woods Road, Chapel Hill
Gary Richman, 1008 Highland Woods Road, Chapel Hill
Jim Ward, Curator, North Carolina Botanical Garden; Chapel Hill Town Council Member
Mark Witcher, 101 Siler’s Fen Court, Chapel Hill

OWASA

Randolph M. Kabrick, P.E., Secretary, OWASA Board
Ed Kerwin, Executive Director
John Greene, P.E., General Manager of Operations
Imtiaz Ahmad, P.E., Director of Planning and Engineering
Walter Gottschalk, Manager of Wastewater Treatment and Biosolids Recycling
Greg Feller, Public Affairs Administrator

Introduction

Ed Kerwin welcomed the citizens and said that the meeting’s primary purpose was to receive feedback about a draft plan for monitoring and evaluating odor at the Mason Farm Wastewater Treatment Plant (WWTP) after scheduled completion of odor-related improvements to four solids digesters by the end of November, 2005.

Mr. Kerwin presented a map of key facilities in the WWTP site and reviewed odor control improvements at the plant in recent years.

Summary of Comments by Citizens

Notes: Comments below are paraphrased and not in actual order. This summary focuses on comments received from citizens; OWASA staff’s responses to questions below are intentionally not included.)

Summary of Community Meeting on September 15, 2005

OWASA personnel at the WWTP are desensitized to odor and the draft monitoring plan should take a different      approach. Monitoring should include getting wind direction and speed, etc. Non-operations personnel should do      odor surveys under stable atmospheric conditions to check for continuous odor sources.

Having WWTP personnel monitor on-site odor is an acceptable management approach that does no harm.

What are the operating options for monitoring odor? Failure of a pump motor should trigger an alarm in the      WWTP control room. Time and money are needed to monitor factors such as temperature and pressure data, but      this effort will be rewarded with better operation.

The odor monitoring and evaluation system should be more than a good, quick response system when odor      occurs. The missing component is measurement of odor elimination.

Who judges whether odor is strong or mild? When odor is released, OWASA should dig into the operating      records, interview staff, go to the house where odor is reported and use a 0-5 scale for rating the odor level.

Solids in the fermenter have an unpleasant smell and they should be targeted for odor elimination. The consulted      hired by OWASA in 2004 identified the first aeration basin as odorous because it receives fermentation      products. Biological systems are tricky.

Does the plant have a variable feedstock pattern? Influent monitoring is needed if so.

How effective is hydrogen sulfide monitoring? Will it be continuous? How many monitors will be used? Have they      been used before? How long will they be used?

There were differences between OWASA staff and OWASA’s consultant in 2004 about appropriate investments      to eliminate odor. If the goal of odor elimination is not met, OWASA has an implied obligation to do more.

Odor elimination can include parallel tracks of operational and capital improvements.

Odor can result from improper design or operation—take a hard look at both of those. An odor consultant should      identify pumps where careful monitoring of pressure is needed.

OWASA appears to be doing a good job in making odor-related improvements at a cost of $5 million. Perfect      odor elimination is not expected. OWASA should notify its neighbors when there is an odor event so that citizens      will know that it is not necessary to report odor to OWASA. Pro-active notices by OWASA to customers should      be part of the monitoring process. OWASA should also notify the Town Manager’s office when there is an odor      event; the Town Council should be kept informed about OWASA’s progress.

There will always be some odor.

(From a resident who has lived in the area since 1958) Odor has been noticeable in the last 15 years.

Odor was noticeable 20 years ago at times.

Odor has not been as bad recently. Why did OWASA begin operating the digesters at a higher temperature in      2001? To inactivate pathogens.

Instruments should indicate odor releases and the need to follow up before odor reaches overload levels.

Will OWASA have high odor alarms? Refineries use alert, action and shut down levels.

How is the Mason Farm Plant protected from flooding? How does the elevation of tanks at the plant compare to      Jordan Lake’s level? The community has seen 100-year flood levels multiple times; a 500-year flood level      criterion should be used in planning and design work.

Can plant operators get to the plant during flood conditions?

When will the Mason Farm plant run out of capacity?

____________________________________________
Prepared by Greg Feller, Public Affairs Administrator

Attachment 2

ADDITIONAL BACKGROUND INFORMATION ABOUT ODOR ELIMINATION
AT THE MASON FARM WASTEWATER TREATMENT PLANT

Need for and planning of the WWTP improvements

In 2002, following several discussions, the OWASA Board of Directors decided to move forward with a project to:

Install filters and an ultraviolet (UV) light disinfection system to increase      the quality of treated wastewater released to Morgan Creek, a tributary      of Jordan Lake, which is a regional water supply source for several      communities. In addition, the enhanced treatment will meet State      standards for the planned reuse of highly treated wastewater for      certain non-potable purposes.
Expand the plant’s “peak month” capacity from 12 to 14.5 million      gallons per day.
Make improvements to better capture and control odorous air in      response to feedback from neighbors.	Above: The new filter structure or "gallery" at the Mason Farm WWTP. This building also houses the new ultraviolet light system for disinfecting wastewater.
Increase the energy efficiency and sustainability of the plant operation      through greater use of methane to power heating and pumping      equipment. Methane is produced in treating biosolids.
Increase the reliability of the WWTP by adding a second large standby power generator and a building to house      it.

In May, 2004, a three-year, $50 million improvement project began at the WWTP in accord with the Town Council’s approval of a special use permit in March, 2004 as noted above. This improvement project is financed primarily from bonds.

Public communications and discussions

In 2002, we began making operating and maintenance changes to achieve short-term reductions in off-site odor and planning the more extensive capital improvements needed to resolve the odor releases for the longer term, and we began a communication process with stakeholders.

Starting in March, 2002 we held several meetings with homeowners’ organizations in Highland Woods and Hunt’s Reserve, and began providing information and periodic updates to customers in the areas where odor was reported. In part, we encouraged customers to report odor when they noticed it at any time of day so that we could promptly investigate to determine and address the source of the odor.

On March 1, 2004, the OWASA Board of Directors formally established a goal of having no off-site objectionable odors at the WWTP. (The resolution adopting this goal was submitted to the Town Council that night for consideration with the WWTP Special Use Permit modification.)

In April, 2004, we held a community meeting to discuss plans for the WWTP improvements including odor elimination work and plans for an odor study and evaluation process with stakeholders following completion of the new digester covers in November, 2005.

In May, 2004, we established and publicized a 24-hour Hotline, 537-4376, for citizens to report odor and check the status of the WWTP improvement project. We continue to provide mail and e-mail project updates and notices to customers about the conditions such as temporary odor releases due to construction and work involving noise, additional traffic, etc.

Odor-related facility improvements and related actions from 2002 to 2004 at the WWTP

General: Increased focus on identifying, cleaning and enclosing locations where wastewater odor can be        released to the open air.

January, 2002: Ceasing operation of old facilities called “trickling filters” where wastewater was exposed to the        open air early in the treatment process.

2003-04: Odor study by the firm of Hazen & Sawyer including assessment of release points and evaluation of      improvement needs.

October, 2003: Installation of covers on tanks where fully treated biosolids are stored temporarily pending      transport to farms. The odor study identified these tanks, which had been open to the air, as a significant source      of odor.

February, 2004: Installation of an odor “scrubber,” which receives air pumped from the biosolids storage facility      and removes odor with mechanical and chemical processes.

Left: A biosolids storage tank with the cover installed in 2003.

Right: The odor scrubber installed in 2004 to receive and treat foul air from our biosolids storage tanks. The scrubber uses a combination of mechanical and chemical processes (rotation of plastic sheeting inside the scrubber and addition of chlorine) to remove odor.

2004, various dates: Installation of a back-up fuel supply, video monitoring system and related procedures so that     methane produced in biosolids processing is fully burned off. Before this system was in place and operating     properly, unburned methane was released at times and resulted in off-site odor conditions.