R&D Project 4 – Investigate solutions to mitigate risk to animal life due to sea water ingress

Marine life can have a disastrous effect on pumped storage machinery. Specific issues which are identified include reduction in recreational fishing, swimming areas, noise and visual pollution. The ejection of material into the environment, brine discharge and the different methods of disposal used are the main cause of pollution. Reverse osmosis (RO) is the preferred method these days, especially when fossil fuels are getting difficult to afford. RO has positives such as better efficiency (30-50%) when compared with distillation type plants (10-30%). 

The water input and output in desalination plants must be pre and post treated. This includes treating for pH, coagulants, Cl, Cu, organics, CO2, H2S and hypoxia. However, the byproducts in these plants is mainly brine with levels up to double that of seawater. Void includes traces of many chemicals which are used in cleaning, including any anticorrosion products that are used in the plant and need to be treated to certain acceptable levels of chemicals before discharge. However, the acceptable levels vary depending on receiving waters and state regulations. 

Discharge of the brine is normally done with the help of a long pipe far into the sea. One way or another the high density of the discharge reaches the bottom layers of receiving waters and can affect marine life, particularly at the bottom layers or boundaries. However, long term effects of discharge have not been documented, but to some extent it is possible that small traces of toxic particles which are used in cleaning RO membranes can be harmful to the innocent marine life and also to the ecosystem. 

The main requirement of the plants is saline water and the construction of certain input and discharge output piping is essential. Lengthy underground piping passes below the ground. The leakages via cracks in rocks to aquifers is a problem and therefore proper monitoring is needed. The monitoring devices of leakage ought to be attached to specific piping during installation. Initially, environment impact assessments must identify key parameters in terms of monitoring during the discharge processes and should recommend certain ongoing monitoring with attached devices to structures installed during the construction of the plant. 

The environment management plans are very important during the plant’s operation to ensure that the plant is operating within environmental standards. Weak planning or monitoring can lead to problems which are difficult to solve later; problems such as re-drilling to install sensors or other monitoring equipment. 

Coastal groundwater aquifers can be contaminated through leakage in the long inlet/outlet pipes. Outlet pipes however contain discharge sludge which is normally highly concentrated brine but it can contain low concentrations of chemicals sometimes at high temperatures. So, be careful monitoring while piping as well as flow processes will be required. Proper monitoring devices should be attached to fixed structures to make sure failsafe subsurface flow processes should be considered before the construction is fully completed. 

Such desalination projects require an environmental impact assessment (EIA) study and the EIA should highly all essential environmental parameters and evaluate potential impacts to air, land, and marine environment. 

The negative impacts of desalination plants on the environment should be kept in check. For example, their adverse effect on land (using seashores for industrial plants/pumping stations rather than aiming for recreation and tourism), impacts on aquifers (leakages of pipes may result in penetration of salt water and can present danger to aquifer), the impact on marine environment, impact of noise (high pressure turbines and pumps) and the high intensity use of energy. 

It is the duty of environmental impact services to take certain impacts into consideration and reduce environment levels to the safe levels with certain restrictions. Since It is the duty of EIS, to facilitate the community and serve at the best level possible. 

It is a known fact that desalination plants generate to two products; clean water and brine concentrate. It is also significant to consider the cost effectiveness and focus brine discharge are obstacles in the widespread use of desalination. Appropriate brine disposal methods incorporated in the plant’s design are capable to reduce the concentrates’ results on receiving waters and coastal groundwater aquifers. 

At the moment, almost 48% of desalination facilities are in the US and most others are found in the Middle East states. Concentrate disposal options include deep well injection, land application, evaporation ponds, brine contractors and zero liquid discharge (ZLD) machineries. Surface water type, deep injection waste water treatment disposal methods are considered most significant in the Australian context. However, certain factors shall be considered such as volume/quantity of concentrate, quality of concentrate, location of desalination plant and environmental regulations. 

Moreover, plastic pollution is another factor which makes the marine life suffer. This can be controlled by reducing the use of single use plastics, by recycling, participating in organising beach clean ups, by imposing bans and with the help of support organisations such as Blue Habits community. It is very important that a country faces less cleanup cost and is fair to say that the economic impact shall always be the first priority. The following table shows the costs and economic impacts of certain continents. 

Comparative analysis shows that Asia is top of the list when it comes to cleaning up. However, Europe and North America are going to have highest average loss to economic value coming from marine tourism, fisheries & aquaculture while cleanup costs are most importantly lower than global average. 

Specific Milestone Objectives

The project comprises 3 milestones, where: 

Milestone 1 is divided into 2 milestones: 

Milestone 1A – Identify and classify potentially affected marine life within the target area 

Milestone 1B – Identify infrastructure components that may be negatively affected by marine life 

Milestone 2 is divided into 3 milestones: 

Milestone 2A – Identify solutions used globally to mitigate impacts on marine life and infrastructure in similar applications. 

Milestone 2B – Evaluate identified possible solutions for differing local conditions around the world 

Milestone 2C – Determine prioritised list of solutions most likely to mitigate identified risks. 

Milestone 3 is divided into 3 milestones: 

Milestone 3A – Develop plans and solutions to mitigate impacts on localised marine life and infrastructure 

Milestone 3B – Develop costing model for various solution components taking into account typical cost variations by region and GDP/capita 

Milestone 3C – Develop decision matrix for determining optimal solution to be deployed based on variables