Seawater Intake and Marine Outfall Systems Seawater intake systems and outfalls, Elmosa.   Great for: RO desalination for raw water supply and brine dispersion, Power Plants, Refineries, Aquaculture, Municipal wastewater
What the Australian EPA said about the InvisiHead: The IH technology surpasses the principles of Integrated Pollution Prevention and Control (detailed in European Union Reference Document on the application of Best Available Techniques (BAT) to Industrial Cooling Systems: Dec 2001) for the selection, design and operation of cooling water systems and effluent discharge. See more.
 Seawater Intake and Outfall Systems - smart super technology with site recognition capabilities, read more
O&M free, no O&M costs associated with system operation. $0 spent on system O&M
The low velocity InvisiHead detects pump energy pulses, recognizes site characteristics as well as operation conditions and application requirements, and commences flow management as planned.  It filters the water and delivers high-quality flow. Low capital costs, 0-O&M costs-see the table below.
Best technology available (BTA) as per
the US EPA Section 316(b); the InvisiHead meets and exceeds the Final Cooling Water Intake 316(b)Rule requirements
The proven
InvisiHead technology  is used as an intake head as well an outfall diffuser; works in both fresh and salt water; capacity unlimited. 
ASE Contact


Elmosa, USA

Self-flow Management

Compete intake and outfall
2018 Brochure
                                    Screening              Elmosa Intakes need     no mechanical screening, 0 fish
Scour proofing
Robust stable durable Structure

Withstanding Cat5 Hurricanes in the Caribbean since 2006

Dredging Turbidity Modeling
Dredging turbidity modeling using the US EPA VP MU3
The InvisiHead diffuser efficiently disperses mining and dredging turbidity, click here

Seawater desalination brine dispersion modeling
Seawater desalination brine dispersion modeling

Cooling water dispersion modeling using the InvisiHead
Cooling Water Dispersion Modeling using US EPA VP UM3Efficient  cooling water dispersion can be achieved by the InvisiHead diffuser fixed at a selected sea bottom location to operate as an outlet to thermal power plants, oil refineries or any warm water disposing systems. The 5m IH diffuses, disperses, spreads, mixes and dilutes water as shown in the US EPA VP UM3 model below.  Heat decays from  41○C to 33.46○ C at 0.02m from the diffuser and reaches the required dilution of 17, the required level just after leaving the diffuser; it drops to 33.01○C at the edge of the ZID or acute zone 30m away from the diffuser; it reaches ambient temperature of 33○ C at 200m away from the diffuser or 100m before reaching the edge of the  Allocated Impact Zone (AIZ).
Flow Hydraulics Compariso
InvisiHead/Wedge wire screen Comparison

InvisiHead intake & outfall for Oil & gas platforms and LPG terminals

  Omni directional round surround up-sideways and down 360 outfall

A Feasibility Study for the Construction of a Next Generation Desalination Plant in New South Wales, Australia

Elmosa Complete System
Elmosa complete intake system with site recognitions capabilities integrated

EO to LD
Comparing Elmosa  outfall to linear pressurized diffuser  systems

Outfall Flow Mngmnt
Outfall 3-D dispersion, mixing & dilution management
High dilution ratio is reached near the outfall

Required dilution reached at the start of the near filed mixing zone
NatSep Sediment Separation
The NatSep sediment separation and flow control basin

Anti biofouling chemical dispensing system
InvisiHead built-in anti biofouling injection system

Elmosa Seawater Intake System
Elmosa Seawater Outfall System
Flow_input_in_4-D_X-Y-Z_space_in_time_T_through_the_InvisiHead_yields_an_output_of _Zs

Public Environmental Review Balmoral South Iron Ore Project
Balmoral South Iron Ore Project

Public Environmental Review
EPA Assessment No 1677

What the Australian EPA said about the InvisiHead: The IH technology surpasses the principles of Integrated Pollution Prevention and Control (detailed in European Union Reference Document on the application of Best Available Techniques (BAT) to Industrial Cooling Systems: Dec 2001) for the selection, design and operation of cooling water systems and effluent discharge


What the California Public Utilities said about the InvisiHead-Page 8.7-135

ASE Contact

The InvisiHead is environmentally smart responsible proactive non-reactive; excludes sediment, marine life and debris; durable, reliable, selective seawater intake & outfall system. It is Self-Reliant, no O&M, no moving parts, no spare parts needed, no backwash or air burst or any kind of operation or maintenance work required. It is the only intake system that makes money and pays back its capital costs
Why should you install the InvisiHead?. Why South Wales Next Generation 1,000,000 m3/d RO plant consultant selected the IH system.
Potential Users: Power and desalination plants, petrochemical and gas complexes, refineries, aquaculture and fish farms, municipal wastewater systems, HVAC, Etc.

This virtually unlimited flow capacity intelligent site-recognizing intake head holistically protects aquatic life; no impingement or fish mortality; it is unattractive to aquatic organisms, sediments, seaweed, or debris; it is selective and delivers clean water; it utilizes local marine currents to sweep away and into the ambient again seaweeds, fish-small and young, jellyfish, sediments and debris if they enter the InvisiHead. The no-return flow is at the outlet. It is out of phase of the major flow channel by 90 thus providing safe passage to marine life to get back into the environment again through the opposite end. In its return to the ambient, flow is in phase with the local currents direction thus all types of onshore mechanical screening-fixed or traveling or both-are no longer required. Negligibly low head loss at about 0.00017m or a pressure drop of 0.017mb means almost 0$ spent on energy. Nearly all pumping energy goes to overcome friction inside the intake pipe. As an outfall, the InvisiHead safely discharges, disperses, mixes and dilutes RO brine, cooling water, and wastewater. The discharges reach equilibrium and disappear into the ambient within the vicinity of the outfall at the beginning of the near field mixing zone. The InvisiHead operates in full compliance with the US EPA Section 316(b) of the Clean Water Act governing the use of cooling water at power plants and industrial facilities (the Final Rule). It Protects biodiversity values of the site and avoids impacts on native vegetation or fauna. No ecological adverse effects are associated with The InvisiHead.

The genuine and original Site-Specific Selective InvisiHead and NatSep technologies reside here at American Eco Systems

Starting January 2013 the InvisiHead
flow transition through the sequential 4 flow phases was upgraded to further improve flow quality and drastically reduce or eliminate flow of sediments or seaweed  if present in the water column; InvisiHead flow velocities: 1. approach is 0.002m/s (0.0066 fps), 2. inlet is 0.09m/s (0.295 fps), 3. outlet is 0.11-0.12m/s (0.36-0.39 fps). No environmental adverse impacts are associated with seawater intake of cooling water or concentrate discharges; low on SDI. Ideal for RO systems. Site and application recognition enables the InvisiHead to fine-tune its flow-management operation and reduce SDI.

Operation-free. Maintenance-free intake system, the InvisiHead
 Payback period in the form of O&M cost savings is short; savings in capital and O&M expenses are high


See Cost_Comparison_between_the_InvisiHead_and_wedge-wire_screen_intakes and InvisiHead technical and cost comparison with onshore traveling screens

NO MORE TROUBLES: Just turn-on the seawater pumps at the pump house and relax. No more clogging. No more pressure drop. No more alarms. No more backwash or air bursting. No more dead fish or any of the aquatic life. No more marine growth or sediments settling in the intake pipe. Simply, no more worries and no more operation or maintenance. All remain in DAY 1 condition for decades to pass.

Seawater Intake & marine outfall System - the philosophy behind the design: let nature manage system operation

Milestone dates: 1981/1982 the InvisiHead was conceived, researched and developed at the reputed St. Anthony Falls Hydraulic Lab of the University of Minnesota; 2002 the InvisiHead has become a BTA as per the US EPA designation; 2009 Australian Ministry of Environment and Australian EPA approved the InvisiHead outfall to be installed in Australian waters; 2009 an Australian mining company selected the InvisiHead for their RO plant intake and brine discharge; in 2010 a British consulting group selected the InvisiHead to serve Sydney's Next Generation's one million m3/d RO desalination plant to supply 2.4 million m3/d of seawater and discharge 1.4 million m3/d; 2013 InvisiHead structure-embedded site and application recognition ability was further fine-tuned to better improve flow management;  2014_water_enters_InvisiHead at 0.09m/s and leaves it at 0.11-0.12m/s to allow supremacy to marine currents to flush out any fish, sediments, or seaweeds if found.

The following images show an Elmosa seawater intake system designed for a coal-fired power plant in SW Africa. The 450m 1600mm HDPE Intake pipe system employs the EVE principle to operate safely and deliver 17,000 to 34,000 m3/h of good quality cooling water
The intake system is entirely located in a 500m-wide strip located within the surf zone. It has to be stabilized well and protected against wave action and excessive scouring.

                                                                                                                                              Anchoring 450m 1600 HDPE pipeline by ballast blocks first                                                                                                                                                                                                                         

Riprapping Enlarge

Armoring for long term stabalization

An InvisiHead system network supplies good quality raw seawater to a 1,000,000m3/d RO desalination plant

Modeling Brine Discharge. A reverse osmosis plant InvisiHead diffuser system discharges, disperses, mixes and dilutes 90,000ppm brine down to less than 4.6% over the 45,000ppm ambient in 8.3m away from the discharge point.
Area of influence of RO brine
Dispersion of brine discharge from seawater reverse osmosis desalination plants. Reverse osmosis RO concentrate dispersal is modeled to demonstrate the InvisiHead brine diffuser performance

Cooling Water Discharge. An InvisiHead diffuser system network discharges, disperses, mixes and dilutes 324,000m3/h of a 2 GW thermal power plant cooling water discharged with 40C and cools down to the ambient of 32 in 10m
Cooling water dispersion modeling
Power Plant Cooling Water Dispersion Modeling using the US EPA VP
The American Eco Systems introduces the Elmosa offshore seawater intake and marine outfall systems - the InvisiHead. InvisiHead flow streamlining is improved in 2012 for better performance. It's specially fit for RO systems due to its high reduction of suspended matter resulting in a lower SDI
Click here to enlarge

We are seawater intake system consultants as well as InvisiHead designers and fabricators. The InvisiHead is a selective water intake system, it lets water in and leaves sediments seaweed and marine life behind. It is a robust stable structure built to remain in full operation even during stormy conditions. It is designed and built to withstand SS Cat 5 hurricanes. It should be installed off the surf zone.

Elmosa revolutionizes the operations of seawater withdrawal and discharge. Flow streamlines fade-in in the intake or fade-away into the ambient in the outfall


See this


See this; also see the Australian EPA Assessment No 1677-Public Environmental Review


In 2012 AES updated and enhanced the flow streamlining of the InvisiHead Intake and outfall systems and improved the hydraulic tuning of the flow streamlines within the approach, entrance, and outlet phases in order to increase the degree of exclusion of marine life, sediment and debris. Avoidance: The change in flow pattern created by the InvisiHead triggers more avoidance response mechanisms in fish both juvenile and adult, thereby avoiding their inflow. The structural integrity of the InvisiHead has been also reinforced to stand up to G5 hurricane force. The IH systems are made of high grade thick stainless steel plates to preserve structural integrity of the systems and remain in full operation throughout the structure's lifetime of.


For the proper design of the seawater intake and outfall, the InvisiHead system has been developed to be the system of choice that naturally handles the flows in both directions. The InvisiHead intake and outfall systems operate to remain in full compliance with the requirements of Section 316(b) of the US EPA Clean Water Act. Both systems -the intake and outfall-meet and exceed the requirements by 40%. The Act requires an intake entrance velocity not to exceed 0.15 m/s. The InvisiHead's is 0.09 m/s. The InvisiHead supports biodiversity, protects and preserves the ecosystem.  It is environmentally friendly in both directions: water withdrawal and discharge. American Eco Systems takes environmental protection and preservation seriously as a top priority that is integrated into system design and operation.

The InvisiHead system works as a superb marine outfall. The dispersion process of effluents is unmatched by any other technology including the widely-used linear riser - diffuser systems. Dilution and blending occurs within a short distance from the radial InvisiHead pointsource. AES has secured the outfall design to remain in full compliance for many decades to come. Both the Australian Ministry of Environment and EPA favored The InvisiHead intake and outfall over the existing linear diffuser types to be installed in Australian offshore waters. See the image below and also see,_Australian_project.pdf, ABTP-Outfall-Modeling.Report , and 


RO Brine dispersion

Flow velocities into the InvisiHead intake head and out of the InvisiHead outfall:

  • 0.002 m/s max. (0.006 fps) <5 meters (15 ft) away from entrance, approaching or dispersing,
  • 0.03 m/s max. (0.1 fps) 1.0 meter (3 ft) away from entrance, approaching or dispersing,
  • 0.09 m/s max. (0.3 fps) at the circumference, entering or releasing,
  • 0.11-0.12 m/s max. (0.4-0.5 fps) at InvisiHead intake outlet. 
Head loss at the InvisiHead approaches zero at 0.00017m. It is engineered to control and drastically reduce or eliminate the inflow of debris, the ingress of fish, mussels and other marine life and virtually uses no pumping energy.
InvisiHead comparison with wedge-wire screen intake heads

InvisiHead system for use as pump strainers, intakes, or discharge marine outfalls in offshore uses and in oil and gas platforms

The InvisiHead operating as a seawater intake or a pump strainer
IH strainerInv.
System fixed to platform, see details
IH strainer
System fixed to the sea floor serving the platform, sea details

The InvisiHead operating as a marine outfall
outfall inv.
System fixed to platform, sea details
System fixed to the sea floor serving the platform, sea details



Copyright 1989-2018 Elmosa, All rights reserved