Top 10 Other – Other Manufacturers for Water and Wastewater

Introduction

In the complex ecosystem of municipal and industrial treatment facilities, the “Big Three”—pumps, pipes, and valves—often dominate the initial design conversation. However, the operational success of a plant frequently hinges on the specialized auxiliary equipment that supports the primary treatment train. When engineers search for the Top 10 Other – Other Manufacturers for Water and Wastewater, they are looking beyond the commodity components to the critical process technologies: chemical feed, headworks, grit removal, aeration, and disinfection systems. These systems act as the central nervous system and metabolic organs of a treatment plant, yet they are often the most difficult to specify correctly due to their specialized nature.

A surprising statistic in facility asset management is that while main influent pumps may consume the most energy, auxiliary systems (the “Other” category) account for up to 60% of corrective maintenance work orders. This disproportionate maintenance burden is often the result of “copy-paste” specifications or overlooking the intricate interface requirements between these specialized subsystems and the main process. Whether it is a polymer dosing skid that clogs due to poor wetting capabilities or a fine screen that allows too much carryover to the bioreactor, the failure of these components can derail the entire permit compliance strategy.

The Top 10 Other – Other Manufacturers for Water and Wastewater encompasses the OEMs that provide the Balance of Plant (BOP) technologies. These are the manufacturers of bar screens, grit classifiers, chemical metering pumps, UV disinfection banks, and sludge dewatering presses. Proper selection here is not just about hydraulic capacity; it is about chemical compatibility, control integration, and the realities of handling ragging, abrasive, or corrosive fluids. This article guides consulting engineers and utility directors through the rigorous selection, specification, and lifecycle management of these critical, yet often underestimated, technologies.

How to Select / Specify

Selecting equipment from the “Other” category requires a shift in mindset from standard hydraulic components to process-dependent machinery. Unlike a standard centrifugal pump which follows affinity laws, equipment like UV reactors or belt filter presses relies on complex biological and chemical interactions. The following criteria outline the engineering rigor required for these systems.

Duty Conditions & Operating Envelope

Defining the operating envelope for auxiliary equipment requires a granular look at process variability. For the Top 10 Other – Other Manufacturers for Water and Wastewater, the definition of “duty point” is often dynamic.

• Turndown Ratios: Chemical feed systems often require 100:1 or 1000:1 turndown ratios to handle the variance between average daily flows and peak wet weather events. Specifying a pump that is accurate only at the top 10% of its curve will lead to massive overdosing during low-flow night intervals.
• Solids Loading vs. Hydraulic Loading: For screening and grit removal, hydraulic capacity is secondary to solids loading rates. A screen sized solely for MGD (Million Gallons per Day) may fail catastrophically during a “first flush” event where solids concentrations triple, blinding the screen panels.
• Intermittent Operations: Many auxiliary systems, such as decanters or intermittent sand filters, operate in batch modes. The equipment must be rated for frequent starts/stops (NEMA Design B or C motors) without overheating or mechanical fatigue.

Materials & Compatibility

The “Other” category frequently deals with the most aggressive fluids in the plant. Material selection goes beyond 316 Stainless Steel.

• Chemical Resistance: Sodium Hypochlorite (bleach) and Ferric Chloride require specific plastics like PVC, CPVC, or exotic alloys like Hastelloy C. Using 316SS for Ferric Chloride injection quills is a common specification error that leads to rapid corrosion.
• Abrasion Resistance: Grit removal systems and sludge dewatering centrifuges deal with high-velocity abrasive particles. Specifications must call out hardness ratings (Brinell or Rockwell C) for wear components, such as scroll edges or vortex chamber liners.
• UV Degradation: Any outdoor equipment or equipment exposed to UV disinfection lights must use UV-stabilized polymers to prevent embrittlement over time.

Hydraulics & Process Performance

Performance in this sector is measured by capture rates, destruction efficiency, and dryness.

• Headloss Constraints: Ancillary equipment like fine screens and UV banks introduce headloss that varies over time as they foul. Hydraulic profiles must account for the “dirty” condition headloss, not just the clean water curve, to prevent upstream channel flooding.
• Process Kinetics: For mixers and aerators, the specification is often “Mixing Energy” (Watts/Volume) or Oxygen Transfer Efficiency (SOTE). These figures must be guaranteed at the worst-case temperature and alpha factor (wastewater characteristics).
• Capture Efficiency: For headworks, specify the Screen Capture Ratio (SCR). A screen that passes 50% of solids may protect the pumps but will wreak havoc on downstream aeration basins.

Installation Environment & Constructability

Many “Other” manufacturers supply skid-mounted systems. While convenient, they introduce specific integration challenges.

• Skid Dimensions vs. Doorways: A classic oversight is specifying a pre-packaged chemical skid or dewatering press that fits the room but cannot fit through the existing access doors or hatches.
• Anchoring & Vibration: Centrifuges and blowers generate significant dynamic loads. Structural engineers need precise static and dynamic load data to design isolation pads and inertia bases correctly.
• Hazardous Area Classifications: Equipment installed in headworks or digester galleries often falls under NFPA 820 Class 1, Division 1 or 2 requirements. Manufacturers must supply explosion-proof (XP) motors and intrinsically safe instrumentation.

Reliability, Redundancy & Failure Modes

In the realm of the Top 10 Other – Other Manufacturers for Water and Wastewater, redundancy is often dictated by critical process continuity.

• N+1 Philosophy: For disinfection and chemical feed, N+1 is mandatory. If the primary hypo pump fails, disinfection stops immediately, leading to a permit violation.
• Shelf Spares: For specialized imported equipment (common in UV and dewatering), lead times for parts can exceed 12 weeks. The specification should mandate a comprehensive spare parts package delivered with the capital equipment.
• Failure Modes: Analyze what happens on power loss. Does the chemical valve fail open or closed? Does the screen blind? Fail-safe positions must be explicitly defined in the control narrative.

Controls & Automation Interfaces

Integration is the most common failure point for auxiliary systems. These manufacturers often supply proprietary “Black Box” control panels.

• Proprietary vs. Open: Avoid proprietary controllers that lock the utility into a single vendor for programming changes. Specify PLC platforms (e.g., Allen-Bradley, Siemens) that match the plant’s SCADA standard.
• Hardwired vs. Networked: Determine if the equipment will communicate via hardwired I/O (reliable, simple) or industrial protocols (EtherNet/IP, Modbus, Profinet). Networked connections offer more data (diagnostics, run hours) but require more complex integration.
• Remote Access: Modern systems offer cellular or VPN remote access for vendor troubleshooting. Security policies must be established to allow this without compromising the plant network.

Lifecycle Cost Drivers

The purchase price is often the smallest component of the total cost of ownership (TCO) for process equipment.

• Consumables: For UV systems, lamp replacement cycles and power consumption dominate TCO. For dewatering, polymer consumption is the main cost driver. Specifications should require guaranteed consumption rates with penalties for non-performance.
• Energy Intensity: Aeration blowers are the largest energy consumer. Selecting a high-speed turbo blower over a positive displacement blower can save 30% in energy but requires cleaner intake air and more sophisticated controls.

Comparison Tables

The following tables categorize the Top 10 Other – Other Manufacturers for Water and Wastewater by technology type. Rather than ranking specific brands, these tables organize the leading equipment categories found in treatment plants, detailing their operational focus and common limitations. This helps engineers identify which type of specialized manufacturer is required for a specific unit process.

Table 1: Top 10 Specialized “Other” Equipment Categories & Manufacturer Examples

Equipment Category	Representative Leaders (Examples)	Primary Strengths	Typical Applications	Critical Limitation / Consideration
1. Chemical Feed / Metering	Watson-Marlow, Prominent, Grundfos, LMI	High precision dosing, wide turndown, chemical resistance	Hypochlorite, Alum, Polymer, pH adjustment	Suction lift limitations; vapor locking with gaseous fluids.
2. Headworks Screening	Huber, Lakeside, JWC Environmental, Duperon	Solids capture, robust mechanical design, compaction	Raw influent screening, protect downstream pumps	Headloss accumulation; carryover rates vary by aperture size.
3. Advanced Grit Removal	Hydro International, Smith & Loveless, Eutek	Vortex separation, fine particle removal (>75 micron)	Headworks, protection of digesters/basins	Requires specific velocity range; organic washout can be an issue.
4. UV Disinfection	Trojan Technologies, Wedeco (Xylem), Ozonia	Chemical-free pathogen inactivation, compact footprint	Final effluent disinfection, reuse water	Lamp fouling/cleaning requirements; heavy power consumption.
5. Aeration & Blowers	Aerzen, Kaeser, Hoffman, APG-Neuros	High efficiency, low noise, wide operating range	Activated sludge basins, digester mixing	High heat rejection; sensitive to intake air quality/dust.
6. Sludge Dewatering	Centrisys, Andritz, Flottweg, Fournier	High cake solids %, automated operation	Biosolids handling, volume reduction	High polymer consumption; noise and vibration (centrifuges).
7. Mixing & Agitation	Sulzer, Flygt, Wilo, Hayward Gordon	Thrust generation, non-clog designs	Anoxic zones, selector tanks, digesters	Ragging on blades; positioning is critical to avoid dead zones.
8. Odor Control	Evoqua, Purafil, Daniel Company	H2S removal, biological and chemical scrubbing	Headworks, lift stations, solids handling buildings	Media life/replacement cost; large physical footprint.
9. Membrane Systems (MBR)	Suez (Veolia), Kubota, DuPont	Superior effluent quality, small plant footprint	Nutrient removal, water reuse, capacity expansion	Membrane fouling; intensive chemical cleaning requirements.
10. Process Instrumentation	Hach, Endress+Hauser, Rosemount, ABB	Real-time analytics, rugged industrial design	DO, pH, ORP, Flow, Level, Suspended Solids monitoring	Calibration drift; probe fouling requires frequent cleaning.

Table 2: Application Fit Matrix – Selecting the Right Tech for the Plant Size

Equipment Type	Small Plants (<1 MGD)	Medium Plants (1-10 MGD)	Large Plants (>10 MGD)	O&M Skill Impact
Screening Technology	Manual bar racks or simple auger screens	Mechanical fine screens (perforated plate or step)	Multi-stage: Coarse bar racks followed by fine band screens	Medium: Automated screens require regular greasing and jam clearing.
Grit Removal	Often omitted or simple channel traps	Vortex grit chambers or detritus tanks	Aerated grit chambers or stacked tray vortex systems	High: Grit pumps and classifiers wear quickly and need constant attention.
Disinfection	Tablet chlorination or simple liquid feed	Open channel UV or Liquid Hypo/Bisulfite	High-intensity UV or On-Site Hypo Generation (OSHG)	Medium-High: UV requires lamp changes; OSHG requires chemical generation expertise.
Dewatering	Drying beds or liquid haul-off	Screw press or Belt filter press	High-speed Centrifuges or heavy-duty belt presses	High: Requires operator attention for polymer tuning and cake consistency.

Engineer & Operator Field Notes

Real-world experience often diverges from the glossy brochures provided by the Top 10 Other – Other Manufacturers for Water and Wastewater. The following notes reflect lessons learned from the field regarding commissioning, specification errors, and maintenance burdens.

Commissioning & Acceptance Testing

Acceptance testing for ancillary equipment must be rigorous. Unlike a pump that either moves water or doesn’t, process equipment involves variables like chemistry and biology.

• Functional Testing with Water vs. Product: A chemical pump tested with water may behave perfectly but fail to prime when pumping viscous polymer or off-gassing sodium hypochlorite. Specifications must require SAT (Site Acceptance Testing) with the actual process fluid.
• Interlock Verification: The most critical safety checks involve interlocks. For UV systems, verify that the banks shut down immediately upon low water level to prevent overheating. For screenings compactors, verify auto-reverse logic when a jam is detected.
• Performance Testing Duration: Do not accept a 2-hour run test. Dewatering equipment and biological processes require 24-48 hour continuous reliability runs to demonstrate thermal stability and consistent performance under varying loads.

Pro Tip: When specifying proprietary control panels for “Other” equipment, mandate a “witnessed factory simulation” where the vendor must demonstrate the SCADA handshake logic before shipping the panel. This prevents weeks of onsite troubleshooting during startup.

Common Specification Mistakes

Errors in the “Other” category often stem from ambiguity.

• The “Or Equal” Trap: Writing “Brand X or Equal” without defining the salient features that make Brand X acceptable allows contractors to submit inferior “look-alike” equipment. Define the critical mechanical constraints (e.g., “shaft diameter,” “bearing L-10 life,” “316SS construction”) to enforce quality.
• Ignoring Access: Placing a heavy mixer or screen in a location without overhead crane access or a hatch guarantees that maintenance will be deferred or impossible. Always include a removal path in the design drawings.
• Voltage Mismatch: Imported equipment (common with European screening and dewatering manufacturers) may be designed for 380V or 400V/50Hz. Ensure specifications explicitly require motors wound for the local standard (e.g., 460V/480V/60Hz) to avoid the need for transformers.

O&M Burden & Strategy

Maintenance of auxiliary equipment is high-frequency and labor-intensive.

• UV Systems: Requires regular cleaning of quartz sleeves (acid bath or mechanical wipers) and lamp replacement every 8,000–12,000 hours. This is a significant O&M budget line item.
• Fine Screens: Brushes and spray bars require regular inspection. Spray water systems often clog with plant reuse water (W3), leading to screen blinding. Ensure strainer systems are installed on the wash water lines.
• Chemical Pumps: Diaphragms and check valves are wear parts. Operators should replace these proactively every 6-12 months rather than waiting for failure.

Troubleshooting Guide

When “Other” equipment fails, look for these common root causes:

• Grit System Washout: If the grit snail/classifier is running but no grit is emerging, check the flow velocity. If the velocity is too high, grit is being blown out of the trap. If too low, organics are settling with the grit, causing odors.
• Chemical Pump Vapor Lock: Common with Sodium Hypochlorite. The pump is running but no flow is registering. Check for off-gassing in the suction line. Install degassing valves or ensure flooded suction to mitigate this.
• Screen Binding: If a mechanical screen trips on overload frequently, check for “rag balls” or timber that the screen cannot lift. Also, check if the downstream water level is submerging the discharge chute, causing backpressure.

Design Details / Calculations

Correct sizing of the Top 10 Other – Other Manufacturers for Water and Wastewater equipment relies on specific process calculations.

Sizing Logic & Methodology

Chemical Feed Sizing:
Do not size metering pumps for the average flow. They must be sized to deliver the maximum required dosage at the peak plant flow, while still being able to turn down for minimum flow.
Equation:
$$Q_{chem} (gph) = frac{Q_{water} (MGD) times Dose (mg/L) times 8.34}{Specific Gravity times % Concentration}$$
Always apply a 1.2 to 1.5 safety factor to the calculated max flow to allow for pump wear and unexpected demand.

Screening Hydraulic Profile:
Screens cause headloss. The upstream channel walls must be high enough to contain the water level at the “blinded” condition (usually assumed at 30-50% blinded).
Rule of Thumb: Allow for at least 6-12 inches of headloss across a fine screen in the hydraulic profile. Failure to do so will trip the high-level alarms in the influent sewer.

Specification Checklist

Ensure these items are in your Division 11 or Division 40 specs:

• Anchor Bolts: Specify 316 Stainless Steel adhesive or wedge anchors. Do not allow galvanized anchors in wet wells or corrosive rooms.
• Nameplates: Require permanent SS nameplates with specific pump/equipment tag numbers (e.g., “P-101”) matched to the plant drawings, not just the manufacturer’s serial number.
• Coating Systems: Standard OEM paint is often insufficient for wastewater atmospheres. Specify a high-build epoxy system or hot-dip galvanizing for carbon steel supports.

Standards & Compliance

• AWWA: Refer to AWWA standards for chemical tanks and feed equipment.
• NFPA 820: The bible for fire protection and ventilation in wastewater treatment. It dictates the electrical classification (Class 1 Div 1/2) for headworks and solids handling areas.
• Ten State Standards: Provides the baseline design criteria for redundancy (e.g., “multiple units shall be provided so that with the largest unit out of service, the remaining units can handle the peak flow”).

Frequently Asked Questions (FAQ)

What qualifies a company as one of the “Top 10 Other” manufacturers?

In the context of this guide, “Top 10 Other” refers to leading Original Equipment Manufacturers (OEMs) that specialize in non-commodity process equipment. These are companies focused on niche technologies like UV disinfection, advanced screening, grit removal, or chemical dosing, rather than general-purpose pumps or valves. Qualifying factors include a proven installed base, available spare parts inventory, and adherence to municipal engineering standards (ASTM, ASME, NEMA).

How do you select the right chemical metering pump technology?

Selection depends on the fluid’s properties and pressure requirements. For clear fluids and high pressures, hydraulic diaphragm pumps are standard. For fluids that off-gas (like sodium hypochlorite) or contain solids (like lime slurry), peristaltic (hose) pumps are often superior because they do not suffer from vapor locking or check valve fouling. Motor-driven pumps are preferred over solenoid-driven pumps for critical municipal applications due to higher reliability.

What is the typical difference between a coarse screen and a fine screen?

Coarse screens (bar racks) typically have openings ranging from 1/2 inch to 2 inches and protect large pumps from logs and rocks. Fine screens have openings from 1mm to 6mm (perforated plate or wedge wire) and are designed to remove rags, plastics, and debris that would foul downstream aeration diffusers or membrane systems. Modern MBR plants often require ultra-fine screening (1mm-2mm).

Why is grit removal often considered the most difficult specification?

Grit removal is challenging because “grit” is undefined. It varies in specific gravity and size. A system designed to remove 2.65 SG sand may fail to remove lighter organic-coated grit (e.g., coffee grounds, eggshells). Engineers must specify the “cut point” (e.g., removal of 95% of grit >150 microns) and consider the specific gravity of the local grit profile.

How often should “Other” ancillary equipment be maintained?

Maintenance intervals vary by technology. UV lamps typically require replacement annually (8,000-12,000 hours). Chemical pump diaphragms and check valves should be replaced every 6-12 months. Screen brushes and spray nozzles should be inspected monthly. Dewatering centrifuges often require a major factory overhaul (scroll rebuilding and balancing) every 15,000-20,000 hours of operation.

Is it better to sole-source specialized equipment or competitively bid it?

Sole-sourcing is advantageous for standardization (reducing spare parts inventory) and when a utility has successfully used a specific technology (e.g., a specific UV system). However, competitive bidding (naming 3 acceptable manufacturers) typically yields better pricing. A “base bid with alternatives” approach allows the utility to evaluate the lifecycle cost of different vendors before award.

Conclusion

Key Takeaways for Engineers & Operators

• Define “Other” early: Recognize that Balance of Plant (BOP) equipment—screens, grit, chemical feed, UV—requires more process-specific engineering than standard pumps.
• Don’t ignore the interface: The physical and digital connection points (flanges, control signals) between ancillary skids and the main plant are the most common failure points.
• Redundancy is king: Apply the N+1 rule strictly to critical process units like disinfection and chemical feed to prevent permit violations.
• Material compatibility: Scrutinize chemical resistance charts for every wetted part, especially for aggressive oxidizers like Hypochlorite and coagulants like Ferric.
• Think TCO: Evaluate energy, consumables (lamps, polymer), and spare parts costs, not just the capital sticker price.
• Verify integration: Ensure proprietary control panels can talk seamlessly to the plant SCADA system before the equipment ships.

Specifying the Top 10 Other – Other Manufacturers for Water and Wastewater is an exercise in managing complexity. While the main influent pumps act as the heart of the facility, these specialized technologies function as the liver and kidneys, performing the essential separation and treatment tasks that ensure regulatory compliance. The “Other” category is vast, covering everything from the microscopic precision of a chemical metering pump to the massive torque of a sludge centrifuge.

For municipal engineers and plant directors, the path to a reliable facility lies in detailed specifications that respect the unique constraints of each technology. It involves moving beyond generic performance clauses to detailed material, construction, and control requirements. By focusing on the interface between these systems, prioritizing maintenance access, and demanding rigorous acceptance testing, utilities can ensure that their ancillary equipment performs as reliably as their main lift stations. Ultimately, the successful integration of these diverse manufacturers determines whether a plant operates smoothly or lives in a state of constant emergency maintenance.

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