LRWRP_Design_Report_Appendix_A.pdf

APPENDIX A

MINUTES OF THE MEETINGS

MEETING MINUTES

BC/City I Azee Ma&

Item

File: 26517-01511

Date:

9-7-2004

?urpose:

(ickoff Meeting - Lompoc Regional WRP Upgrade Project

Ciiy Staff BC Staff Jim Beck Mike Anderson Susan Halpin Ron Appleton Dennis Butts Michael Drennan Jeff Palmer Azee Malik Ken Ryan Eric Wahlberg

I Description Azee reviewed the agenda of discussion topics (attached) before starting. These minutes summarize the items discussed and decisions made, including action items.

Place:

Lompoc Regional WRP

Called By:

rime Start:

1O:OO A.M.

INTRODUCTIONS

Recorded By:

Time Finish:

1 :00 P.M.

After the introductions, Jim indicated to keep a single point of contact. On City's side Susan will be the contact person and on BC's side Azee will be the contact person. All electrical/instrurnentation questions should also go through Susan.

CITY'S COMMENTS - PROPOSED TREATMENT

SCHEME

Azee provided overview of BC proposed treatment scheme.

Dennis:

Flow measurement - lack ability to separately measure three influent flow sources (AFB, Vandenburg Village, and Lompoc). Provide redundancy of metering flows. Provide ability to double check meters from VAFB and W and with the plant influent and effluent.

Could gnt removal occur before influent pumping to reduce wear and tear on pumps?

Action Pam

Item Description Equalization of flow needed prior to Anoxic zone - Could emergency storage basin be used? Operators in San Luis Obispo wished they had flow equalization upstream of oxidation.

Master Plan presented two proposals for secondary clarifiers.

Alternative with 3 new clarifiers is preferred. City wants capability of 200 percent recycle.

Master Plan App. C, Table 1 - Flow predicted to be 4.8 mgd.

We are expecting a project to be completed by 2008, where that plant will already be at capacity. Perhaps we should already be thinking of increasing capacity. Azee indicated BC d be designing for 5.4 mgd.

How long will be the hydraulic detention time in the oxidation ditch? The concern here is the growth of Nocordia foams.

Dennis distributed a list of questions from the City's Operation and Maintenance staff (attached).

Susan:

She now realizes that the emergency holding basin is proposed to be used as wet-weather holding basin.

Wants to reduce the multiple chemicals currently being used.

Wants the biologcal treatment system and metals removal system to be as simple as possible.

I Azee - just by adding W, three chemicals would be eliminated.

Susan will be happy if the UV system won't require tremendous hours for cleaning tubes, etc. Azee - proposed UV system has automatic tube cleaning.

Eric - Three guiding principles: 1. Simple, 2. Use existing basins, 3. Reduce existing pumping requirements.

f . :

We are not asking for an alternative analysis of other treatment schemes with two exceptions: 1) the influent pumping station must be evaluated, and 2) evaluate keeping anaerobic digestion with building aerobic digestion.

We are asking BC to implement the plant proposed in the proposal. We are only expecting to tweak the proposed plant in the brainstorming session.

Action Party

Item

Description I Metals removal is decided, and the City is moving forward with financing. 4

We don't want any more odors.

I Current proposed design of 5.4 mgd is acceptable for next 20 years.

We are looking for assistance with the regulatory strategy with the Regional Board - to negotiate a longer time schedule.

RWQCB Contact: Todd Stanley - Area Engineer. (Previously Mike Hggms.)

PROJECT ISSUES/EXPECTATIONS

Susan - Actively include rank and file employees in brainstorming sessions (to the extent possible).

Clearly define goals and strategy for brainstorming session.

What product should we expect out of the brainstorming session?

Guiding project strategies is to keep it simple. Keep BNR simple and keep UV system simple.

Azee -Brainstorm concepts to obtain agreement on the final plant flow scheme and plant layout after the brainstorming sessions. Meeting minutes will c o n k decisions.

Susan - Effluent flow meter has been calibrated many times and it always checks out, but historically, there is not a lot of confidence in the effluent flow data.

Azee - Design details are important and will be addressed during the design review meetings following brainstorming.

WASTEWATER CHARACTERIZATION AND

SAMPLING PLAN

Ron - Measurement of additional wastewater constituents is needed to characterize the wastewater for oxidation ditch process design. The goal of the wastewater characterization program is to determine the particulate and soluble fractions, biodegradable and non-biodegradable fractions, and nutrient concentrations for process modeling. Daily composite influent samples are needed for one week and diurnal grab samples are needed for one day to adequately characterize the wastewater and the diurnal loading pattern.

Action Partv

City to conduct sampling/ testing

In addition to total COD, total cBOD, TSS, and VSS currently measured by the plant laboratory, constituents such as soluble COD, soluble BOD, total Kjeldahl nitrogen (TKN), ammonia nitrogen, alkalinity are needed for the wastewater characterization program. BC will prepare a memorandum summarizing the requested samples and constituents for wastewater characterization.

BRAINSTORMING SESSIONS

Susan wants to know in advance what subjects will be discussed in upcoming brainstorming session. Azee distributed a list of topics to be discussed in Brainstorming Session No. 1 (9-16-04) and Brainstorming Session No. 2 (9-27-04) (attached).

Michael Drennan suggested a list of ground rules to be reviewed by the brainstorming session participants and discussed how to meet Susan's important success factor and to get as much involvement as possible. It was agreed that BC would facilitate the session.

METAL REMOVAL

Ron reviewed influent and effluent trace metals data. It appears that if a significant portion of effluent copper is particulate, improved secondary clarifier solids removal (through polymer addition for example) could provide compliance with the copper ultimate discharge limit (UDL). Discussion with the Regional Board is needed for the beryllium and thallium discharge limits of "zero," the molybdenum discharge limit, and the TDS discharge limit.

Susan wants a meeting with the Regional Board set within a couple of weeks. Michael Drennan suggested meeting with "upper level folk."

Action Party

Ron to prepare memo for sampling by 9/14/04

Michael to draft ground rules for brainstorming session by 9/13/04

Susan to set up a meeting with Board

Item

Tim:

I Looking for a letter from BC detailing the additional expense that d be incurred on the part of the City if the interim project has to be done (i.e., if the City can't get an extension on the interim standards due to become effective in 2006).

KJ will continue to assist City on reports to be done for the Regional Board in the near future but City hasn't decided who will do the January 2006 report.

Jim will be looking to BC for overall regulatory assistance and to develop a long term regulatory strategy.

MISCELLANEOUS ITEMS

Eric raised the issue of TDS. Vandenburg Village's water has a TDS of 1,600 mg/L and amounts to about 1 /6 the WWTP flow. VAFB's water has a TDS of 500 mg/L and amounts to about 1/6 the WWlT flow. City water has a TDS of 800-950 mg/L after water treatment. Calculation shows raw water TDS should be about 950 mg/L. Adding 400 mg/L TDS for "domestic addition," results in 1,350 mg/L wastewater, which does not meet the permit. Jim said that they didn't think Lompoc has a lot of water softeners but thought they must.

BC - this calculation shows they probably don't.

Ron described the Salinity Management Plan done by Zone 7.

Jeff - Plant piping is extremely corroded. BC, in large major expansion, wrapped the pipes but not the fittings. Cathodic protection long gone.

Susan prefers pipes in chase rather than buried.

3W Pumps - Very badly corroded. They should be replaced.

Drafting Standards - Susan discussed the drafting standards with the City engineer after the kickoff meeting. BC to use internal drafting standards for the project except for Base and Title sheets. Susan to provide the information for the Base and Title sheets.

Equipment Numbering System -Jeff provided the equipment numbering system for the project.

Engineering Division Standards and Practice - Susan provided a copy of the Enweering Division Standards and Practice.

Action Party

Azee to draft a letter

Michael to develop regulatory strategy by

9/13/04

Susan to Confirm

Attachments

Purpose: Brainstorming Session No. 1 - Liquid Stream

Attendees:

Ciq Staff Tom Ajailar Leonard Avellanes

File: 26517-011/1

Date:

9-1 6-2004

Lompoc Regional WRP Upgrade Project

Dennis Butts Jim Cleckley Lynn David Toe Gonzales

Item

1.

Place:

Lompoc Regional WRP

Called By:

BC/City

Time Start:

8:00 A.M.

City Staff Susan Halpin Gary Herman

Recorded By:

Azee Malik

Time Finish:

12:OO P.M.

City Staff Dorin Marrs Larry Michaels

City Staff Ken Ryan

Roger House Jeff Palmer Mike Landon Rick Pepper Phil Lafeyeet Peter Phillips David Lewis ICay Prater

Description

INTRODUCTIONS - Azee

An agenda packet of discussion material was provided to each attendee as they arrived to the brainstorming meeting (attached).

After the introductions, Azee reviewed the upcoming schedule and the agenda topics for this brainstorming session. Meetings will be held for brainstorming sessions, collective review of technical memos, presentation of the draft report, and for design submittals.

These minutes summarize the items discussed and recommendations/decisions made, including action items.

BRAINSTORMING SESSION RULES - Pervaiz

Pervaiz highlighted the classic ground rules for brainstorming sessions presented in a Sept 8,2004 memorandum provided to all attendees, and encouraged participation by all.

DESIGN FLOWS - Ron

The existing flow data is not very good for selecting the project design flows. The plant has only an effluent flow meter.

Influent flow measurements are limited to W and VAFB flows There are no daily total influent flow measurements on which tc base accurate design flow projections for PDWF and PWWF.

The effluent flow meter does not show much daily or seasonal flow variation.

BC Staff Mike Anderson Pemaiz Anwar Ron Appleton Galr Jones Dave Murray Azee Malik

Action Party

Ron to discuss possible flow meter problems with Jeff after the meeting

I tern 1 Description I Action Pam

Brief period influent flow measurements taken by hlGD Technologies were incorporated into the I<-J flow projections incorporated into the Master Plan.

There are several housing projects planned or underway that may impact flow projections during the design period for Lompoc and W. VAFB flows are expected to remain stable. Azee requested updated population projections from Suzan.

BC suggested the use of strap-on flow meters for influent flow metering from now through the next winter. Plant recycle flows may impact the usefulness of data collected from these meters.

Flows above maximum treatment capacity are diverted to the ESB by throttling the leaking inlet gate to the influent pump station wet well.

The following Design Flows were tentatively agreed:

ADWF = 5.5 mgd (vs 5.44 in the Master Plan)

PDWF = 9.5 mgd (vs 8.2)

PWWF = 15 mgd (vs 13.6)

Flows above the design PWWF will be diverted to the ESB.

'LOW METERING - Azee

The K-J Master Plan presents two alternatives (A at -$1.4M & I?

at -$130I<) for new influent flow metering. BC recommends Alt B, but with a different flow meter: MGDYs ADFM Velocity Profiler. BC recommended that these same type flow meters be installed on the W and VAFB sewers. BC's experience with these flow meters has been extremely good with no in-situ calibration required.

The City is concerned with deep grit deposits in the 48" interceptor sewer just upstream of the 54" wet well inlet sewer, and believes these deposits on the meter sensor head may affect its accuracy.

The City reported significant headlosses through the fine screens installed upstream of the influent pumping station. These screens replaced climber bar screens, but raised the water surfacc elevation in the upstream sewers, causing grit to settle out due to lower velocity flows. BC (Garr) suggested that to solve the grit deposition problem, replace the £he screens with coarse screens and move the fine screens downstream of influent pumping.

The City reported a 2:1 range in SS in influent samples taken at the upstream influent sampling manhole vs at the headworks.

The City expressed concern that representative samples be obtained bv all sam~lers.

:ity to furnish ,laming data from he Bldg Dept.

:ity to investigate.

3C to check grit :ffect on sensor vith MGD rechnologies

BC to investigate Gads suggestion

Item Descrhtion

I The City (Jeff) suggested consideration of a flow meter that uses radar and never touches the water.

I The City (Peter) said that a vactor truck unloadmg station is needed at the plant, but that there will be no septage unloading.

GRIT REMOVAL - Mike

At the kickoff meeting, the City (Dennis) suggested that grit removal be installed upstream of influent pumping. In response, BC prepared a preliminary profle sketch for such an installation for illustration. It showed a very deep excavation with a pump gallery approximately 49' below ground surface. BC cannot recommend such a costly facility and the City agreed. Grit removal will be downstream of influent pumping.

Because of the grit load, BC recommends the aerated grit removal process over the vortex grit removal process. Aerated grit removal tanks spread the grit load over several pumps while vortex tanks have only one pump, so aerated grit offers less possibility of overwhelming and plugging a grit pump during peak gnt loading.

BC proposed one aerated grit removal tank with two (or three) grit hoppers (cells) within the tank. This tank would be arranged with a flow bypass and for future mirror imaging with an identical tank utilizing a common pump gallery.

BC discussed candidate grit processing equipment and their advantages and limitations. This equipment included Eutek's Slurrycup and Snail, and Huber's Coanda grit classifier, which may require an upstream cyclone. BC recommended stainless steel materials for whatever equipment is selected during detailec design.

INFLUENT PUMPS - Mike

The internal condition of the pump discharge manifold is unknown, but it is assumed to be poor and in need of replacement.

There are four existing influent pumps of the same capacity.

Pump rotation is right handed for two pumps and left handed for the other two pumps. There is space for a fifth pump. Two of the pumps have VFDs and the other two have Magna Drives.

Action Party

:ff to send radar leter info to BC.

iC to invesagate

The Magna Drives do not provide good control, but the City has expelienced numerous VFD failures of several makes of VFDs at this facility.

BC will replace the pumps with four new identical bottom suction pumps supported by the station structure, four new motors at the floor above, four Magna drives or identical VFDs, new wiring, and possibly even a new MCC.

VFDs will be the soft start type per City request.

The pumps will be sized so that two pumps can deliver the PWWF and two pumps wiU be spares (less capacity than the existing pumps). All operating pumps will run at the same speed

BC will design repairs for the pump suction draft tubes and replacement of the pump inlet elbows and discharge piping, valves and manifold.

SECONDARY TREATMENT - Ron

I BC described the location and configuration of the oxidation ditch system. The City pointed out that the location shown on the proposal figure extends beyond the plant fence line.

Additionally, the location is outside the flood control berm, so the site grading plan will need to modify the berm accordingly.

BC will evaluate two types of aeration/mixing systems for the oxidation ditch - mechanical aerators and jet aeration. A jet aeration system may require a small aeration air blower.

I BC described how a mixed liquor wasting system will be configured to simplify solids residence time (SRT) control and act as a classifymg selector to selectively waste from the surface of the mixed liquor to control Nocardia and foam.

I BC described how the oxidation ditch and secondary clarifiers will be designed to handle peak dry weather flow (i.e., dry weather peak diurnal flows). Peak wet weather flows will be diverted between the grit tanks and oxidation ditch to the emergency storage basin, where it will be stored and returned as influent flows allow.

I Action Pam iC Elec team to ivestigate VFD ailures during detail iesign.

dETAL REMOVAL - Ron

BC described how the existing aeration tanks and secondary clarifiers will be converted for use as secondary effluent equalization basins and metals removal flocculator/clarifiers, respectively. Secondaty effluent flows will be diverted between the new secondary clarifiers and the filter influent pumping station to the equalization basins (modified existing aeration tanks). The h a 1 flow variations will be eliminated so that the downstream processes - metals precipitation, atration, and W disinfection - can be designed for a constant flowrate.

BC described that based on the recent series of monthly metals analysis, copper and molybdenum appear to be the only metals that present a compliance problem. Current effluent copper limits are dose to the ultimate discharge limit (UDL), so only a small increase in copper removal is needed for compliance. In the short term, enhanced suspended solids removal in the existing secondary clarifiers (e.g., through polymer addition) may be all that is needed.

Dr. Lewis described recent final effluent copper, molybdenum, and mercury results collected using "ultraclean" sampling techniques. The results show lower concentrations for copper and mercury, so that copper compliance could be demonstrated using these sampling techniques.

UV DISINFECTION - Dave

BC described three types of Mercury discharge UV lamps available and the key features of each. Photos of example equipment were reviewed, including one showing an automatic cleaning system.

The City requested that a crane be provided to lift out the lamp racks for maintenance. BC noted that a typical lamp module for this size project might weigh around 100 pounds and could be lifted out by two people.

BC recommended selection of low pressure/high intensity W lamps with quick start capability and an integral mechanical cleaning system.

The City asked if a bleach backup disinfection system would be provided. BC replied that a redundant lamp bank will be provided per SWRCB requirements so that one bank can be removed for service without having to shut down flow or divert effluent. BC also indicated that bleach would be required in the upgraded plant for other purposes so that the existing bleach system would not be removed, although it would no longer be needed for disinfection of effluent.

Action Party

IC to verify weight )f lainp module

I tern Description I

Action Party

I BC recommended covering the UV disinfection channels to control algae.

To reduce costs, the UV design will be for equalized secondary effluent flow.

The design will conform to Title 22 and the National Standards for Disinfected/Filtered Effluent.

EFFLUENT FILTERS - Dave

BC recommended the use of cloth media filters, which are replacing sand type filters across the USA. BC indicated that the filter media should last fiom 2 to 7 years before requiring replacement.

BC recommended selection of automatic units with continuous backwash, in standard pre-fabricated stainless steel or concrete modules of - 3mgd capacity.

To reduce costs, the hlters design will be for equalized secondary effluent flow.

The design will conform to Title 22 and the National Standards for Disinfected/Filtered Effluent.

The City (Dennis) suggested to enclose the effluent filters in a building (pre-fabricated type) to prevent algae growth and dust accumulation.

PLANT LAYOUT - Azee

BC recommended modifications to the proposed plant layout discussed at the kickoff meeting on Sept 7: (1) Move the W disinfection system to the east side of the existing chlorine contact tank in order to take best advantage of the existing effluent pumps;

and (2) locate the hlters and the chemical facility east of the existing secondary sedimentation tanks, which will become tertiary sedimentation tanks in the upgrade. The City indicated that it is planning to install an upgraded sodium hypochlorite system in this same area.

Attachment: Agenda packet hsan indicated that he City wiU review he layout and idvise BC

Attendees:

City Staff Tom A@r Leonard Arellanes

File: 26517-01 1 / 1

Date:

9-27-2004

Purpose: Brainstorming Session No. 2 - Solids Handling Facilities

Lompoc Regional WRP Upgrade Project

Dennis Butts Lynn David

City Staff Susan Halpin Gary Herman Jim Beck

Place:

Lompoc Regional WRY

Called By:

BC/City

Time Start:

1:30 PM

Item

Recorded By:

Ken Fonda

Time Finish:

4:00 P.M.

City Staff Phil Careyette Larry Michels Jim cleckley Delia Lagua

City Staff Ken Ryan Jeff Palmer Mike Landon IGy Prater

Description

[NTRODUCTIONS - Azee An agenda packet of discussion material was provided to each ~ttendee as they arrived to the brainstorming meeting (attached).

ifter the introductions, Azee reviewed the upcoming schedule and he agenda topics for this brainstorming session. These minutes ,urnmarize the items discussed and recornmendations/decisions nade, including action items.

SCHEDULE - Azee 4zee reviewed the upcoming schedule and reported the draft TMs Rould be prepared and submitted in the near future and the draft PDR would be submitted in January

REVIEW EXISTING FACILITIES - City I'he City described current operation practices and condition of the solids handling facilities. Information provided by the City is summarized below.

Gravity Thickener (GT)

Currently thicken PS and WAS.

Chlorine added to prevent solids floating problems

A diaphragm pump is used to feed the GT. When sludge is too thick this type of pump has difficulty pumping. Primary solids are pumped fairly thin as a result

BC Staff Pervaiz Anwar Ron Appleton Ken Fonda Azee Malik Perry Schafer

Purpose: Brainstorming Session No. 2 - Solids Handling Facilities

Lompoc Regional WRP Upgrade Project

Item

The drive unit and turn table need to be rehabilitated if kept as a part of the process.

Current operation does not use polymer to enhance performance that would explain some of the relatively low thickened solids concentration

Cover was added primarily for safety with odors being sent to the biofilter for supply air.

Anaerobic Digesters

Operate as primary and secondary digesters in series.

Secondary digester overflows by gravity to the lagoons. The City described the digester operation as being virtually "bullet proof' and was happy with the operation. The digesters have shown great resilience even when some equipment has been out of service for an extended period of time. The City reported that volatile solids destruction has consistently been high

Both have floating covers. The City would consider fixed covers if %esters are rehabilitated.

Primary digester has gas mixing that appears to be working well. The City is planning on installing chopper pumps on its existing recirculation system. The City would consider mechanical or pump mixing if digesters are rehabilitated.

Digesters are heated using waste heat from the engine driver pumps. Gas domes are uninsulated and are a source of lost heat.

The City noted that much of the existing piping is corroded and needs to be replaced. Grooved pipes where victaulic couplings are used have rusted through in several areas.

The City reported they had had foaming problems at one time, but it seemed to correct itself.

Sludge lagoons

Lagoons are fed by gravity from the secondary dgester.

Sludge is diluted to help it flow better.

File: 26517-011/1

Item Description

Water is also added on the surface of the lagoons to help prevent odors (site walk after the meethg confirmed that odors were minimal from the operating lagoon)

Portable "pit hog7' pump is used and portable pipes are used to convey sludge to the drymg beds during the drying season. Sludge is pumped down to a depth of about 10 feet.

This leaves about 5 feet that do not get pumped which reduces the effective volume of the lagoon. Permanent piping was recommended in the K-J Master plan Update.

No "pure" storage time is provided in the lagoon to ensure "Class A" pathogen destruction. The lagoons operate in a fill and draw mode.

I Air drying and storage

Drying bed is equipped with sand layer and underdrain to promote drymg by gravity and air. Sludge place in the beds dries fairly rapidly due to drainage system and drying winds.

Dried product is about 90% dry.

The City sends the product to a cornposting facility in Santa Maria to produce a Class A product. Hauling costs are about $29.70 per wet ton to this facibty. Material hauled to this site is not tested for Class A parameters before leaving Lompoc facility, so they can't say what they send is Class A.

Some testing in the past seemed to indicated the highly driec produce did meet Class A.

Dust is only a problem when it is loaded from piles into trucks. Currently air dried product is primarily small chunks of very hard biosolids mated. Some sand is entrained in the air dried product as it is removed from the drying bed.

Mechanical dewatering is not considered necessary at this time, but may be considered in the future. Mechanical dewatering would add complexity to the process.

;OLIDS HANDLING OBJECTIVES - Azee I Objectives listed in the handout were reviewed to confirm these were the correct objectives. Planning for future on-site production of a Class A material should be included in the design. Although it may currently be unnecessary to demonstrate biosolids are Class A when they are co-composted in Santa Maria, the City wants to have the solids handltng facilities designed and built to consistently produce Class A on site.

File: 26517-011/1

Purpose: ÿ rainstorm&^ Session No. 2 - Solids Handling Facilities

Item Description

=VIEW 40 CFR 503 Class A requirements - Perry I Perry gave a brief overview of the 6 alternatives to achieve Class

A status. The only one that would most likely apply to this facility would be Alternative 4. Pathogen destruction would need to be verified by monitoring and testing. Improvements to lagoons and air drying could consistently produce a Class A material on site.

I There has been a limited amount of data that appears to support the City's ability to meet Class A from air drying operations. It appears they may be achieving Class A by air drying to a very high degree, (about 90% solids or so, thus killing pathogens through desiccation - essentially the dryness of the material does not provide enough moisture for organisms to continue to live.

In order to provide a Class A biosolid at lower final air-dried solids content, substantial storage time within the lagoons would be required. The City of San Jose has been using a lagoon and air drying system to produce Class A biosolids with two years of storage and with an air dried product at about 75% solids. Perry shared the results of a recent WERF study he has led for the pas1 several years which has developed guidelines and conditions for lagoon storage and air drymg to achieve Class A biosolids. A copy of the WERF report will be provided to the City.

[MPACT OF METALS REMOVAL ON BIOSOLIDS

QUALITY - Ron I Primary metals of concern would be Copper and Molybdenum.

BC doesn't anticipate that the metals removal process would significantly increase the level of metals in the biosolids removed from the site. Further evaluation of potential impact of increased metals removal will be included in the metals removal process TM.

jOLIDS HANDLING OPTIONS - Ken I Three solids handling options included in the handouts were reviewed. Discussions during the liquid process brainstorming session settled on mixed liquor wasting. Therefore, evaluation of solids handling options would.be based on this method of solids wasting. The City agreed that the option to directly waste mixed liquor to the lagoons will not be evaluated further because of the extensive lagoon volume that would be needed. Since the thickening and digestion systems are so closely related, digestion and thickening will be evaluated together.

File: 26517-011/1

Action Party

3C will provide a :opy of the WERF yeport to the City :or lagoon and air irymg guidelines.

Item

Thickening systems shown on the handout were discussed briefly. The City asked for more explanation of why DAF thickening operation is moderately complex. BC explained that the main components of DAFT include an air compressor system, a pressurization system, level control and polymer addition. Adjustments to these components make it somewhat more complex than the two other systems listed in the table shown in the handouts. However, other sites BC has designed DAF thickening for have reported the system to be operator friendly and provides a consistent product going to the digesters.

Because they are less hydraulically limited than the other two systems they would be a more "forgiving system" when there were changes in the ML wasting rate. Because there would be no primary solids to aid in the thickening process polymer addition may be needed to ensure high solids capture and a well thickened solids for DAF thickening and the system will be designed with the ability to chemically condition the feed sludge if required. San Luis Obispo has been operating their cothickening DAFT without polymer and consistently produces good solids concentration and solids capture.

DIGESTION AND LAGOON OPTIONS - Perry Anaerobic digestion - advantages and disadvantages

Volatile solids reduction of wasted activated sludge is expected to be in the 30 to 35% range which is less than required to achieve Class B biosolids. Therefore, gas production is expected to be lower as well.

Digested solids going to lagoons would be anaerobic already making continued digestion easier and less odorous.

They are able to meet Class A with high temperature digestion, but this would be more complex to operate. Higl temperature options will not be included in the solids handling TM.

Gas produced is currently used for running engine driven blowers. The City reported the Santa Barbara Air District has an H2S limit on raw gas of about 760 ppm. This number will be confirmed later.

File: 26517-01 1 /1

Lompoc Regional WRl' Upgrade Project

Item Description

I Aerobic digestion - advantages and disadvantages

Volatile solids reduction is expected to be about the same as anaerobic digestion. Aerobic digesters operate best in the low 20 deg C range.

There are no know facilities that send aerobically digested sludge to lagoons.

There is no methane gas produced

Odors in lagoons may be %her because the aerobic sludge would need to become anaerobic

This process can also achieve Class A though Auto Thermal Aerobic Digestion process, but this produces a high amount of odors.

I Lagoon options

Lagoons following anaerobic digestion are most common.

Lagoons following aerobic %estion could be more odorous

As noted in the Master Plan Update, permanent piping would be provided from the lagoons to the drying bed.

Additional improvements would include a floating dredge that could reach the bottom of the lagoon and a surface paddle mixer to keep the top layer aerobic and reduce scum accumulation.

Some additional space is available adjacent to the existing lagoons. Plans for a park across the street may limit use of this space. The area adjacent to the river is heavily wooded and may present an environmental habitat issue.

UR DRYING AND FLOW EQUALIZATION - Perry I Existing air drylng bed has underdrain, gravel layer and sand layer removed. The surface would be paved to allow for use of heavy equipment for turning of solids being dried to speed up the drying process and loading. Removal of sand layer would eliminate sand being loaded with dried solids being removed from the bed. This should also reduce the amount of air drying bed space needed.

During the winter months, a portion of the drying bed could be used for flow equalization and storm water retention. This coulc be done in compartments to reduce the amount of cleanup after a storm event.

File: 26517-011/1

Action Partv

Item

Description

ZOGENERATION - Azee I Azee said a recent study completed for Goletta showed that the breakpoint cost for electricity is about 8 cents per kw. Since the City produces its own power, they control the electric rate they charge themselves which may make cogeneration feasible.

from a non-co~enerating engine.

ENGINE DFUVEN BLOWERS -Jim Cleckley/Mike Landon City's Master Plan recommended to replace the existing E n p e Driven Blowers with motor-driven blowers. Brown and Caldwell recommended scheme would not need the existing aeration blowers. A question was raised if the existing engines can be used for power generation. BC indicated that as the existing engines are almost 30 years old an economic evaluation study needs to be completed to compare the costs to operate and maintain and possibly rehabilitate the engines with the revenue that would be generated or the electrical cost savings which may be realized. Also, it would need to be investigated if the Santa Barbara hir Pollution Control District would allow emissions

Attachment: Agenda packet

File: 26517-011 /1

Action Party

City to authorize BC to perform the economic evaluatior for use of existing engines for power generation

Purpose: Instrumentation and Electrical Meeting and Site Visit

Attendees:

City Staff Susan Halpin Jeff Palmer Dennis Butts

BC Staff Mike Puccio Erick Lozano

File: 265 17-?

Date:

9-29-2004

Lompoc Regional WRP Upgrade Project

Item

1.

Description

Place:

Lompoc Regional WRP

Called By:

Time Start:

1 1 :00 A.M.

SENERAL

The meeting commenced with a general discussion with Susan Halpin md Jeff Palmer. Site visit followed with Jeff Palmer and Dennis 3utts.

Recorded By:

Time Finish:

3:00 P.M.

[NSTRUMENTS

t was agreed that existing transmitters and analyzers in remaining Irocess areas will be replaced. Other type instruments like pressure ;witches, level switches, etc. will be analyzed during final design on a :ase-by-case basis. All instruments in rehabbed areas will be eplaced.

'LC HARDWARE

'uccio indicated that there were only two PLC manufacturers, Allen hadley and Modicon, in the wastewater industry that support their roducts to make a twenty year investment in a control system.

'uccio suggested that the PLC Spec. Be an open spec. and Allen 3radley would be first choice based on quality of product, product ,upport and service.

Action Party

Halpin will investigate City policy on sole sourcing PLCs.

Puccio will arrange for Modicon and Allen Bradley representatives to visit with City staff.

I

SCADA SOFTWARE AND HARDWARE

Puccio indicated that there were several SCADA software manufacturers (Allen Bradley, Intellution and Wonderware) in the wastewater industry and indicated that Wonderware was a favorite of some clients because of ease of modifying points and screens.

The number and location of SCADA workstations were discussed and until the process selection is made, no firm number can be decided.

For now, two workstations will be provided in the existing control room and one workstation each at the influent pump station, the blower building, and the new UV building. It was decided to provide SCADA Ethernet ports at any location that may be considered for a workstation.

It was decided that the existing control room would continue to be utilized as the control room with at least two new SCADA workstations installed on furniture provided by the City. The existing instruments and process flow diagram on the wall would be removed from the existing control room during construction.

PROGRAMMING

Puccio discussed the value of the City getting up to speed on programming the PLC and SCADA software that is selected for the project. In addition, he offered B&C services for the programming effort on the project as an addition to the construction phase services.

ELECTRICAL

The extent of the electrical changes required could not be determined until the process selections have been made. Most of the electrical equipment is thirty years old and at the end of their useful life. Puccio suggested that most of the electrical equipment be replaced as part of this project.

A discussion of the VFD problems at the influent pump station occurred and Jeff presented Puccio with notes from past electrical failure on the VFDs.

Action Partv

'uccio will arrange or Wonderware and Ulen Bradley epresentatives to risit with City staff.

%ccio will review Iotes from influent ?ump station VFD Failures.