The Optimization State – Alabama

These are some news and views submitted by the AWOP states.  Please use this for your enlightenment, enrichment and maybe even your entertainment!  AND think about what your state wants to share for the next Optimization State.

Alabama has recently released their latest AWOP newsletter – Drawing the Graph.  The newsletter highlights activities in the state’s optimization program.  This issue shares how many of the state’s surface water systems are optimized – 38%.  There is also an article on the “costs” of optimization that really shows what a water system gets for their investment.  On the technical side, the newsletter examines automatic flushing for DBP control and Extended Terminal Subfluidization Wash.

You can review the Alabama newsletter HERE.   Is this something your state might be able to do?

The Optimization State – Kentucky

These are some news and views submitted by the AWOP states.  Please use this for your enlightenment, enrichment and maybe even your entertainment!  AND think about what your state wants to share for the next Optimization State.

The Kentucky AWOP team bid farewell to Jim Hamon, a founding member of the Kentucky AWOP, when he retired on October 1, 2010.  Even with budget constraints, Russell Neal was hired to fill that vacancy on January 16, 2011.  Russell comes to the group with a BS in Biology with a minor in Chemistry and a MS in Aquaculture and Aquatic Science from Kentucky State University.  Russell began his environmental work at the Kentucky State University in performing aquaculture research.  Russell will be providing technical assistance to drinking water systems that are located in the Hazard & Frankfort Regional offices.

The first quarter of 2011 has been full of activity, with the Kentucky AWOP team working to update the AWOP.  Kentucky made the decision to split the AWOP into two categories, a Microbial AWOP and a Disinfectants and Disinfection Byproducts (D/DBP) AWOP.  For the Microbial AWOP, the updates have not affected the existing goals, but rather the awards criteria.  Kentucky presents Microbial Optimization Certificates annually.  To receive an Optimization Certificate for being optimized, in addition to meeting the Microbial AWOP goals, the system must have no turbidity violations for the calendar year.  Systems must also submit turbidity data monthly.

For the D/DBP AWOP, specific D/DBP goals were set for both the treatment plant and distribution system.  Plant tap goals include TTHM and HAA5 limits, treated TOC limits, TOC performance removal ratio limits, and CT requirements.  Distribution goals include both short and long term TTHM and HAA5 limits, flushing requirements, and disinfectant residual limits.  Kentucky will be presenting D/DBP Optimization Certificates annually.  To receive an Optimization Certificate for being optimized, in addition to meeting the D/DBP AWOP goals, the system must have no Disinfection Byproduct violations for the calendar year.  Systems must also submit Plant Tap TTHM and HAA5, Distribution TTHM and HAA5, and Plant TOC data quarterly.

These new rules were put in place to further encourage systems to protect public health and maintain compliance.  Now for both the Microbial and D/DBP AWOP, in order for systems to be considered for optimization they must formally commit to AWOP.  To do this they must submit a letter of commitment, formally adopt the goals, and post them at a prominent location at their plant. To be in the running for either the Microbial AWOP Champion Award or the D/DBP AWOP Champion Award, a three year longevity award, the system will not be considered if they have any SDWA violations for the three year period.

The Optimization State

News and views from the AWOP states.  Please use this for your enlightenment, enrichment and maybe even your entertainment!  AND think about what your state wants to share for the next AWOP News.

Pennsylvania

Pennsylvania and EPA Work on Distribution System Optimization Study: In a continuing effort by Pennsylvania to develop a distribution system optimization program that is consistent with the most recent protocols and monitoring techniques, Pennsylvania staff participated in an EPA Area Wide Optimization Program (AWOP) Distribution System Optimization field event in Johnstown, Pennsylvania on August 24-27, 2010.  This was the sixth detailed study conducted by the AWOP Distribution System Optimization Team on a Pennsylvania system.

Pennsylvania staff worked with a team of industry leaders in the field of distribution system optimization on a rigorous 4-day comprehensive evaluation of the Greater Johnstown Water Authority system.  The purpose of the field event was to gather comprehensive distribution system data utilizing a calculated flush time distribution system sample collection protocol.  The goal of this sample protocol is to establish a consistent method that will provide an accurate and representative sample of water quality at a specific point in the distribution system.  Both fire hydrants and residential taps were evaluated using this protocol.  Extensive staff interviews were also incorporated as part of this field event.  The interviews are used to evaluate the system’s administrative and management capabilities as it relates to the implementation of distribution system optimization.

In addition, continual monitoring equipment was deployed at two of the system’s storage tanks.  The equipment monitored for turbidity, free chlorine, pH, conductivity and temperature.  Currently, the Pennsylvania Department of Environmental Protection is the only state agency to utilize this valuable monitoring equipment.

The data collected by the team was used to develop a chlorine map of the distribution system, which is a method of comparatively estimating water age and disinfection by-product (DBP) formation at key locations.  Samples were shipped to a certified lab for definitive TTHM and HAA5 levels to compare with field data.  Ultimately, the data will be used to evaluate the overall chlorine mapping process as an accurate indicator of DBP formation throughout the distribution system.  The information and experience gained during this field event will help assure that Pennsylvania’s distribution system optimization program is developed in a manner consistent with national protocols and standards.  Pennsylvania’s participation on this team of industry leaders is extremely beneficial and will continue via monthly conference calls and semi-annual field events.

Pennsylvania will follow up with the Greater Johnstown Water Authority with the final report as well as to determine if any special studies or operational changes are occurring based on the information gathered during the event.  A special study approach has been established and was presented to the system to ensure that educated process control decisions are made towards optimization without compromising public health.

The contact for this activity is Paul Handke at (717) 783-3900 or phandke@state.pa.us.

Texas

Texas Optimization Program (TOP): The Texas Optimization Program’s Core Team has had a busy summer, having done a mandatory Comprehensive Performance Evaluation (mCPE), an Optimization CPE (oCPE), and two Special Performance Evaluations (SPEs) since the beginning of June.  Additionally, the team, along with Region 6 EPA, held Session 4 of the Disinfection By-Product Performance Based Training (DBP PBT) in July.

The Optimization CPE, also a joint project led by Region 6, was done at the City of Port Arthur’s 24 MGD Water Purification Plant.  The City of Port Arthur was selected by EPA as an Environmental Justice Program focus site and the CPE demonstrated that while not optimized, the water treatment plant is not a cause for concern.

The DBP PBT has been a success with the participating operators, the Core Team, and Region 6.  The original 7 plants are continuing to gather data and have recently begun implementing their individual control strategies.  Session 5 is being held in Austin on October 14 and at that time, the operators from each plant will present data demonstrating whether or not their chosen control strategy has been successful, discuss the findings with the other operators and the trainers, and make a decision on whether or not to continue with that strategy or to try something different.  The final PBT session will be held in Austin in January, 2011.

Texas continues to participate in the Region 6 AWOP.  Two representatives attended the quarterly meeting in Des Moines in September and they will be participating in the multi-state CPE in Oklahoma in November.

Microbial Optimization Goals – Then and Now

By Larry DeMers and Bob Hegg – Process Applications, Inc.

The microbial optimization goals provide the basis for the national Area Wide Optimization Program.  These goals were introduced to the AWOP states at the beginning of the program and were used to encourage a different level of performance from surface water treatment plants than the regulatory requirements at the time.  However, the initial development of these goals goes back even further in time.  The first Composite Correction Program handbook published by EPA in 1991 for water treatment optimization does not specifically list performance goals.  Performance is discussed under the “Conducting Performance Assessment” section of the CPE methodology and reference is made to achieving 2 NTU from sedimentation basins and 0.1 NTU from filters.  Included in a discussion in filter performance after a backwash, acceptable performance is described as a turbidity increase of 0.2 to 0.3 NTU for less than 10 minutes after a backwash.  Moving on to the 1998 edition of the Composite Correction Handbook, Chapter 2 is devoted to protection of public health from microbial pathogens, and the research basis for the optimization goals and specific performance goals are described within the chapter.  The turbidity performance goals, which all AWOP participants are familiar with, are summarized below.

Individual Sedimentation Basin Performance

  • Settled water turbidity less than 1 NTU 95 percent of the time when annual average raw water turbidity is less than or equal to 10 NTU.  This goal increases to 2 NTU when the annual average raw water turbidity is greater than 10 NTU.

Individual Filter Effluent Performance (IFE)

  • Filtered water turbidity ≤ 0.1 NTU 95 % of the time (excluding 15 minute period following backwashes) based on maximum values recorded during 4-hour time increments.
  • Maximum filtered water turbidity of 0.3 NTU.
  • Initiate backwash after turbidity breakthrough has occurred and before turbidity exceeds 0.1 NTU.
  • Maximum filtered water turbidity following backwash of < 0.3 NTU.
  • Maximum backwash recovery period of 15 minutes (i.e., return to < 0.1 NTU).

Although specific goals were not established for combined filter effluent turbidity (CFE) in the 1998 edition of the handbook, the same goals as with IFE are applied to CFE when interpreting performance at this location.  This point is demonstrated in the handbook in the CPE methodology section on assessing plant performance.

Further discussion on interpreting the filter backwash recovery performance goals occurs in Chapter 4 under supplemental data collection.  This section states that the same goals (i.e., limit turbidity spike to < 0.3 NTU and recover to ≤ 0.1 NTU within 15 minutes) should be used to assess filters with filter-to-waste capability.  The 15 minute recovery period starts when the filter begins filtering during the filter-to-waste period.  The rationale for this approach is that the filter-to-waste period is a key indicator of a plant’s process control, and monitoring of performance should start immediately after the filter is placed back in service.  This description is important to remember, since NOLT has made changes to this interpretation that are currently being applied during Targeted Performance Improvement (TPI) activities (e.g., CPEs, PBT), and they will be discussed later in this article.

Since the last update of the turbidity performance goals in 1998, further research using higher resolution turbidimeters and particle counters have confirmed the validity of these goals and provided the basis for refinements.  One specific refinement is the use of two significant figures when referring to the filtration goals (i.e., 0.10 in place of 0.1 NTU, 0.30 in place of 0.3 NTU).  One specific research project that is included in the “Why Optimize” presentation during PBT references work conducted by Emelko (Water Quality Technology Conference, 2000) on Cryposporidium removal during filtration.  The researchers were able to demonstrate 5 to 6 log removal during optimized, stable filter operation, and the measured turbidity during this period of operation was approximately 0.04 NTU.  At the end of the filter run the log removal decreased to 2 to 3 log with a corresponding turbidity increase to approximately 0.10 NTU.  Advances in turbidimeter resolution also support the refinement in turbidity readings.  A common low range process turbidimeter currently used in water treatment plants (i.e., Hach 1720E) has an accuracy of ± 2 % of the reading or ± 0.015 NTU from 0 to 40 NTU.

A recent refinement to the sedimentation and filtration optimization goals was reported in the August 2009 edition of AWOP News.  This article described a recommended approach for establishing the frequency of data collection for continuous reading turbidimeters when pursuing process optimization.  For sedimentation basins a frequency of at least 15 minutes is recommended.  For individual filters and combined filter effluent at least a 1 minute frequency is recommended.  Additional information on this refinement can be found in the article.

For the last microbial goal refinement discussed in this article, revisions to the filter-to-waste performance goal will be reviewed.  The performance goals for plants without filter-to-waste capability remain the same, other than the change to using two significant figures.  These plants should strive to limit their turbidity spike following backwash to < 0.30 NTU and should achieve ≤ 0.10 NTU within 15 minutes of return to service.  Recent experience from PBT plants implementing special studies has shown that filter backwash spikes can be reduced substantially through use of practices such as filter rest periods and the extended terminal subfluidization wash (ETSW).  In many cases filter spikes can be reduced to < 0.10 NTU.  For filters with filter-to-waste capability the performance goals have changed to the following:

  • Minimize the turbidity spike during the filter-to-waste period (i.e., record the highest turbidity and direct optimization efforts at minimizing this value).
  • Return the filter to service at ≤ 0.10 NTU.

This refinement does not establish a maximum turbidity value or length of time to the filter-to-waste period.  The primary reason for this change is that, under the revised goal, filters are not returned to service until the turbidity is ≤ 0.10 NTU thus limiting the need to establish specific maximum turbidity and duration goals for water that is going to waste.  The revised goal recommends that plant operators monitor performance during filter-to-waste and minimize the turbidity spike during this period, a practice that has not been pursued by plants in the past but is a key activity during PBT.  The magnitude of the spike during the filter-to-waste period can be used as a relative indicator of filter conditioning prior to the filter going into service.  Most plant operators have a desire to keep filter-to-waste periods short, since they want to minimize wasting production water.  Consequently, operators are motivated to achieve ≤ 0.10 NTU as quickly as possible during filter-to-waste.

An example post filter backwash assessment from a recent Oregon PBT session is shown in the chart below.  These turbidity data describe the performance of a filter during the filter-to-waste period.  During the initial part of the period the turbidity reflects the quality of the backwash water exiting the filter.  Once this water is removed, settled water passes through the filter, and the maximum turbidity of 0.13 NTU occurs at about 12 minutes into the period.  A turbidity of 0.10 NTU is reached between 17 to 18 minutes.  At this time the plant operator changed from filter-to-waste to filter-to-clearwell operation.

It is important to understand that the initial lag in the turbidity response can be impacted by the size of the filter, including the underdrain volume, as well as the filter-to-waste rate.  Ideally, the filter-to-waste rate is similar to the filtration rate; however, this is not always the case for plants with different size waste piping.  It is also important to understand that the potential exists to minimize the turbidity spike and duration of the filter-to-waste period described by the performance in the chart.  As described previously, many PBT operators have been able to utilize the special study approach to maintain the turbidity spike during filter-to-waste at ≤ 0.10 NTU.

Almost 20 years after the publication of the Composite Correction Program handbook for surface water treatment plants, the basis for the turbidity goals remains in place.  The refinements described in this article have been made based on industry research, changes in instrumentation capability, and the considerable amount of experience gained through implementing AWOP activities.

The Optimization State

News and views from the AWOP states.  Please use this for your enlightenment, enrichment and maybe even your entertainment!  AND think about what your state wants to share for the next AWOP News.

Iowa

Greenfield Success Story

In fall of 2007, the Iowa DNR field staff offered training in the use of the Optimization Assessment Software (OAS) to all of the state’s 32 surface water systems.  In response to the training, several water system operators began using OAS and sending it in to the central office for review each month.  One of these was Water Plant Foreman Garry Miller of the Greenfield Municipal Utilities (GMU) water plant.  The plant utilizes water from six wells, Greenfield Lake, Nodaway Lake, and the Middle Nodaway River to produce water for a population of approximately 2,300 people.  Potassium permanganate is added at the Greenfield Lake inlet, and then water flows by gravity to the treatment plant, where coagulant is added.  Flocculation/sedimentation is accomplished through a Trident Microfloc clarifier/filtration system followed by disinfection and fluoridation.  Because of the lack of sedimentation in this process, the plant is classified as direct filtration.

Miller began using the OAS software in November of 2007, and he noted with his first electronic submittal that the plant had filter to waste, but that filters were put back in service once turbidity dropped below 0.40 NTU.  He thought he could lower that to 0.20 NTU or lower.  He also mentioned that he was in the process of finding a computer programmer to repair a problem in the software that he thought would reduce the combined filter effluent (CFE) to less than 0.1 NTU 95 percent of the time.  On November 29, 2007, the computer programmer arrived and found that at 12:01 a.m. each morning, the computer program was taking that combined filter effluent turbidity measurement and adding it to the 12:00 a.m. measurement and recording it in the spreadsheets as the reading for 12:01 a.m., effectively doubling the reading.  Many times, this 12:01 a.m. reading was the highest reading of the day.  The OAS spreadsheet showed an immediate effect following the fix.  The 95th percentile for CFE did not change from 0.19 NTU, but GMU went from meeting the CFE optimization goal of 0.10 NTU 17.5 percent of the time, to meeting it 49.5 percent of the time after the computer program fix.  It also provided a more accurate picture of how things were going at the plant.

Program fix to more accurately portray CFE turbidity

After taking a look at the data in the OAS spreadsheets in November and December of 2007, Jennifer Bunton of IDNR contacted Miller about days with very high turbidities and found that Garry was reporting turbidity data even on days when filter maintenance was being performed, because he hadn’t realized these numbers were not considered valid for compliance.  They also discussed the fact that most of the maximum daily values were occurring during backwash and filter to waste.  Miller thought about this and decided that maybe there was a problem in the control panel, because the relays were supposed to block turbidity data from reaching the plant computer and spreadsheets during backwash and filter to waste.  He thought that perhaps the input signal to the relay was coming from the wrong terminal in the plant PLC, so he talked with his manager about it, and they agreed this could be a problem.  In November of 2008, Miller and the Utilities Superintendent, Duane Armstead, were able to negotiate a deal with the control panel technician and he came out to fix the problem.  Results were evident immediately, as the OAS data showed. 

Control panel fixed to eliminate recording during backwashes and filter to waste periods

In the year since the backwash and filter to waste data were blocked from recording, GMU has gone from meeting the individual filter goal of 0.10 NTU zero percent of the time to meeting the goal 68.8 percent of the time—a drastic improvement.  The GMU plant is also now meeting the CFE goal 97.3 percent of the time.  There have not been a lot of operational changes at the plant, and Miller has not been able to participate in the state’s Performance Based Training program because of demands on his time, but GMU now has more representative data to use for optimization purposes.  This shows a very different picture from what IDNR saw during its initial data collection efforts in 2006, and it also shows the benefit of just providing optimization information to systems in a format that is easy to understand.  Miller agrees, saying, “I guess I never paid too much attention to all this before I started using the OAS spreadsheets…Thanks for planting the seed as far as keeping a closer eye on how your plant is truly performing.”

Miller says he is a “behind the scenes kind of guy,” but Bunton disagrees.  “It’s only because Garry took the initiative to start thinking about why his data looked the way it did that he was able to convince his manager to make the changes necessary to portray the true picture of what was going on at the GMU plant.  His attitude and persistence are to be commended and his actions show that he is truly a professional.” ♦