Filter Parts – Why General Filter MULTIBLOCK, MULTICRETE II, ESSD Washtroughs, Media & In-Bed Air Wash Grids

What is The General Filter Advantage? UNDERSTANDING FILTRATION Can improve operation an existing plant. (expansion & upgrades) Thoroughly backwash filter media with air/water Provide even distribution of backwash water and air throughout the filter basin. Reduce backwash waste Reduce off line time with shorter backwash durations Complete the scope for a new plant.

We have the complete Filter System! WASHTROUGHS CONTROLS MEDIA AIR GRIDS UNDERDRAINS

MULTIBLOCK® Underdrain Details Similar to Other Block Underdrains 12” tall x 11” wide 36” length HDPE structural foam Compensating dual lateral design Media retaining or gravel support designs Snap fit connection. NSF/ANSI STANDARD 61 With or without Laser Shield® Competitor W x H L Block Connection Leopold-S® 11” x 12” 48” Snap fit Severn Trent –U Block™ 12” x 12” 36” Snap fit, single gasket Inflico Tetra™ –U Roberts Trilateral® 10 5/8” x 12 1/2” Bell & spigot and O-ring These are the overall details of the underdrain. Spacing of the laterals are on 12” centers. The blocks are joined to form longer laterals. The make up blocks (those that are not full length) are factory cut to length. HDPE (high density polyethylene) is the same material used by the other block manufacturers. The blocks are injection molded. The compensating lateral design is explained further later on but this is simply having more than one chamber inside the block to allow balancing of flow down a length of lateral.

Modular Design Easy to Install Blocks snap together to form laterals 25 lbs/block - HDPE material MULTIBLOCK Shield factory installed (if used) Rebar pullout tested prior to block installation Laterals installed in rows +/- 1/8” level Set on 3/4” grout bed Joints filled with grout Max length 30’ on each side of flume

Laser Shield® Provides Unique Direct Media Retention 0.06” stainless steel plate 0.008” (0.2 mm) slot openings Minimizes opening surface area per volume Stainless steel screws Based on nozzle design

Comparison of the Two Shields We Offer Porous bead design 3,000 sq.in. / sq.ft. of filter Laser Shield 16 sq.in. / sq.ft. of filter Porous bead difficult to clean No clear passage for water Lower profile Clearly defined, sharp edge openings Retains smaller media MS-500 Shield 500 micron 3/4" thickness Laser Shield 0.20 mm slots 0.06" thickness

MULTIBLOCK Cover A Wide Range of Flow Conditions Backwash Water only 5-30 gpm/sq.ft. Air only 1-5 scfm/sq.ft. Combined backwash 5 gpm/sq.ft. and 3 scfm/sq.ft. is typical consult us for specific applications Filtration 2-10 gpm/sq.ft. Maldistribution in large basins Less than +/- 10% Typical flow rates for backwash and filtration. Combined air-water rates other than those listed may be possible depending on the length of the lateral and the volume of air and water we are trying to pass.

General Filter Scope of Supply Underdrain blocks Media retaining Laser Shield™ Rebar over flume Flume bridges End caps Ancillary equipment Air headers, washtroughs, media, controls, etc. Pre-treatment equipment Don’t forget backwash waste treatment products, such as: ContraFAST Packaged Plate Settlers Here is what we provide. Basically everything needed for the filter system can be provided by us. One of our differentiating qualities against other block underdrain suppliers is that we offer a wide range of other equipment items for a plant. This provides single source responsibility for the entire plant, and not just the filter.

Application Areas Single, Dual and Mixed media Concrete filters Conventional layout CenTROL® filter Steel filters Packaged plants Trident® and Trident HS Systems Aquarius® Systems MULTIBLOCK can be used in almost any gravity filter system. Installations (some may not be in operation yet) to date include conventional concrete filters, CenTROL, steel gravity filters and ACTIFLOC & Aquarius units. We prefer not to use the Shield on wastewater applications due to potential biological fouling. This may change after we gain more operating experience.

Competition: Block Underdrains-Standard Height We are seeing more and more installations where porous caps style underdrains are starting to fail. They have accumulated enough solids over the years that result in higher and higher backwash pressure resulting in ultimate failure Leopold Type S IMS Cap (porous bead) used for direct retention. Patented water recovery channel and inside baffles Severn Trent – Also Offered By IDI Porous bead plate used for direct retention Roberts Filter Group Will use this to get in the door to promote Infinity. Lately have been very aggressive. In promoting the Air Grids. Main selling feature is the single 30 ft block. This eliminates the joints, clips and seals. Backwash with water only, use air grid above. Can be retrofitted into existing low profile filter cells.

Competition-Low Profile Underdrains Limited to basins less than 20’ from feed flume. Concern for dead spots on top of pyramids or between units. Maldistribution is a key point to compete against. Maximum air and backwash water rates may be limited. AWI Phoenix Underdrain System Used with our MULTIWASH Troughs Ovivo EWT™ Flexscour® WesTech hasn’t seen a lot of these. EIMCO Folded Plate Not seen many of these Johnson TRITON® Used by WesTech in various applications. Not suitable for high A/W rates Leopold LP Max length 16’ from flume Highly competitive.

MULTICRETE II Underdrain Provides Installation Options Standard ACI 318 loadings 1,600 psf , 1,400 psf  Doweled Rebar Design Exploded view shows the parts of the underdrain system. Pier forms are 6” dia. sch 40 PVC. We used to notch these at the top to lock in the forms but have moving the locking mechanism to the form itself (details in a couple of slides from here). The underdrain pans have also been changed (details in a few slides) to make them stronger and easier to install. We provide the piers, pans, inserts and nozzles. Contractor supplies the concrete and rebar. Two side attachment options are shown: The keyway design eliminates the doweling of the rebar into the wall. A stainless steel angle is used to support the pans at the perimeter during concrete pouring. The doweled design requires horizontal rebar to be drilled into the wall and is shown here with a poured concrete ledge (2” wide required). A perimeter angle can also be used. Keyway Design

MULTICRETE II® Offers Long-Term Experience Floor and nozzle design based on pre-cast design from 1960’s Monolithic construction with over 19 years experience Eliminated most joints Light weight forms easier to handle Nozzle design and spacing remained MULTICRETE II 653,225sq.ft. 385+ sites Millions of nozzles We originally had pre-cast concrete panels for our MULTICRETE underdrain. These were heavy and could crack during shipment. The biggest downside was the underdrain had multiple joints where the panels joined together. To eliminate the multiple joints the MULTICRETE II underdrain was first installed in 1986. The same nozzles used for MULTICRETE are used for MULTICRETE II and also in steel plate underdrain filters we sell. Our experience with nozzle underdrains is extensive and very positive with very few failures with MULTICRETE II. For MULTICRETE II, over 50 installations are lime softening, over 40 are wastewater and the balance being surface water clarification or iron/manganese removal plants. Mid 1960’s 1986 Today

Quarter-Turn Insert Reduces Installation Time, Ensures Proper Fit MULTICRETE II Form (from below) Insert (inverted) and form opening Our new concrete insert design uses an elliptica shape on the bottom of the insert and a matching opening in the form. The inserted is installed in the opening and turned about ¼ of a turn until it hits the stop lobe. At this point the insert is in tight without a chance of working free or being kicked over during concrete installation. Our old design required attachment with ABS solvent which took longer for the contractor to install and if they didn’t the inserts attached right, they may kick them over during the concrete pour. Stop Lobe Pier locking ring Insert installed in form Less than 1/8” deflection during installation

MULTICRETE II Provides Simple Formwork Installation Inspected by our Service Personnel Install nozzles after curing Here is the basic installation process. Vertical rebar are pulled tested to 3,600 lbs uplift to ensure they are properly installed prior to placing the forms. 10% of the anchors are randomly tested and if any fail in a cell, all anchors are tested. Once the forms and rebar are installed, our field service engineers inspect the installation. Elevation tolerance is +/- ¼” measured at the top of the inserts. Concrete pour for the floor and support piers happens at the same time. Concrete along the walls and into the pier supports is vibrated to eliminate voids. Concrete is finished to the top of the red protector caps, no more or no less. Once the concrete has cured for at least 48 hours the red caps can be removed and the nozzles installed. Anchorage pull tested Concrete installed

Dual Air Distribution Ensures Uniform Backwash Identical headloss nozzles Air blanket (secondary distribution) A visual description of what the air wash header and nozzles air metering orifices are doing during backwash. Remember the blanket moves in all directions to ensure uniform distribution. Air header & risers (primary distribution) Low headloss open plenum

Nozzle Design Ensures Uniform Distribution Assembly screws  slot openings > tailpipe area To prevent plugging we use a wedge wire opening in the nozzle head as shown in the nozzle cross section. If debris in the filter cell gets into the slot opening and get pushed in they get into a larger space and will push through rather than becoming stuck. In addition, the tailpipe opening area is actually smaller than the nozzle slot open area. This allows a small degree of nozzle fouling without effecting distribution. The tailpipe is actually the hydraulic control point of the nozzle assembly. Tailpipe section (control orifice) Nozzle cross-section

Application Areas All concrete filter applications Conventional layout CenTROL® MULTIWASH Filtration Process Our preferred underdrain for Wastewater Filtration Single, Dual and Mixed media Mixed media needs support gravel MULTIBLOCK can be used in almost any gravity filter system. Installations (some may not be in operation yet) to date include conventional concrete filters, CenTROL, steel gravity filters and ACTIFLOC & Aquarius units. We prefer not to use the Shield on wastewater applications due to potential biological fouling. This may change after we gain more operating experience.

Competition: Monolithic Floor Underdrains IDI Form Using tighter nozzle spacing (4”-6”) to keep others out IDI has good experience base. Orthos Underdrain Orthos much lower experience on complete supply Eimco Castkleen Large underdrain form = 48” square. Will use concrete pre-poured support walls or piers Adjustable insert height for leveling

MULTIBLOCK or MULTICRETE II? Lower profile No access Packaged steel plants Concrete tanks Gravel or gravelless Limited water/air rates Mixed media MULTICRETE II Larger plenum Less headloss Plenum access Concrete tanks Gravel or gravelless WTP and WWTP Unlimited water/air rates

ESSD™ Washtroughs Deliver Durability and Cost Effectiveness 417+ installations Light gage (12-16 ga.) material Webbing adds strength

ESSDs Apply To Range Of Systems Hydraulic capacity same as other troughs Also used in pre-treatment basins CONTRAFLO® Units Settling basins Clarifiers Longer unsupported span compared to FRP Up to 36 ft. length vs. 24 ft. MULTIWASH ® baffles factory attached to trough

General Filter offers a number of filter Medias to complete a “system” package Sand media Depth 24” Size – 0.45 – 0.55 mm Fe < 0.3 ppm Anthracite Size 0.6-0.8 mm Fe < 4 ppm Dual media 12” sand 0.45 – 0.55 mm 18” of anthracite 0.8 – 1.0 mm or 1.0 – 1.2 mm Fe < 7 ppm Mixed Media Garnet, Sand, Anthracite Manganese Anthra/Sand Natural media Media conditioned in the field Developed in 1980’s Overcomes shortcomings of greensand Various media sizes available Media selection is based on Raw water quality Desired effluent quality 252+ installations since 1980 Largest installation – 39.7 MGD – Eagan, MN All granular media configurations can be coated as Manganese ANTHRA/SAND. Our advantage is that since our media is coated in-situ, everything is coated even the support gravel, making effective use of all the material in the vessel.

Manganese Anthra/sand Still Outstanding compared to competition. Recent studies (2012) by John E. Tobiason, PhD, PE, BCEE, Professor, Environmental and Water Resources Graduate Program, Department of Civil and Environmental Engineering, University of Massachusetts conducted some recent lab testing comparing Manganese Anthra/sand to macrolite and pyrolucite and reported “In general, Jonathan found that the coating method worked well and seemed to provide a coating that worked well very soon after being put into service. “ This favorable results is expected to help increase sales in the Northeast.

In-Bed Air Wash Grids Located at media- gravel interface Headers PVC Stainless Steel Laterals Polyethylene Distributors ABS plastic Slotted lateral

Filter Parts Summary Many options for all situations more options than any other manufacturer Cost effective designs MULTIBLOCK or MULTICRETE with MULTIWASH is an AWESOME SYSTEM!!!!!!!!! Sell the features and benefits to beat the competition: Plant tours Increasing your offering to enhance your position Case Studies…. We’ve done quite a few of them this year!

Filter Parts – Why General Filter? MULTIBLOCK, MULTICRETE II, ESSD Washtroughs, Media & In-Bed Air Wash Grids