The Return Water Quality (RWQ) Tool from in2Dredging (i2D) predicts the quality of return water, i.e. the amount of sediment contained in the water flowing out of a given reclamation area.
When dredged material is pumped into a reclamation area, the sediment and water mixture flows over the reclamation area and possibly through one or more settling basins. During this process, the material settles and the excess water or return water is drained via one or more outlet into the receiving water body. Depending on the type of dredged material and the dimensions of the reclamation area (and settling basin), the return water might contain suspended particles when returning to the surface water.
A question that often comes up is: Will our reclamation area have enough capacity to hold the amount of dredged material, considering factors such as bulking and rock or particle degradation? Furthermore, are settling basin(s) needed and if yes, how large do they need to be in order to let the fine particles settle and to return clear water or water not exceeding the environmental water quality requirements?
The RWQ model generates a particle size distribution and follows the settlement of each particle size along the length of the sand fill (reclamation area) and/or sedimentation (settling) basin. The model provides the concentration and particle sizes still suspended in the return water. The width, length, depth of fill/and or basin can be optimised to improve sedimentation and return water quality.
When the discharge rate and mixture properties are provided or estimated, RWQ can predict the quality of the return water. The tool was initially built for a specific project and has been developed, fine-tuned and validated ever since. Field measurements have driven the development of the design tool. Only a limited amount of literature on sedimentation and erosion processes was utilised to maintain its suitability for a practical design application. This approach has led to a tool that supports dredging engineers when designing an optimal reclamation area and sedimentation basin(s). The more complex Computation Fluid Dynamic modelling is often unrealistic and impractical as a design tool.
Many projects have shown that the definition of the input parameters drives the accuracy of the predictions. An especially high definition of the fines (the proportion of material smaller than 63 micrometres) is key to providing an accurate prediction. The highest practically achievable fine content definition leads to g/l or kg/m3, which can be linked through analysis of water samples, correlation and extrapolation, to turbidity, and therefore environmental regulations. i2D use rules of thumb and experience to ensure that the return water quality is compliant with the allowed turbidity levels.
Designing reclamation areas and sedimentation basins
Predicting return water quality
Comparing the amount of suspended solids in return water with allowed turbidity levels
Providing insight into particle segregation on reclamation areas
Determining the ideal discharge rate and mixture density to improve sedimentation rates
Recent Posts on RWQ
Major Update of Pumps ‘n Pipeline (PnP) v1.6.8
Pumps ‘n Pipeline (PnP) v1.6.8, a suction and discharge production estimation tool, has had a major update. PnP was first released four years ago in 2016 and its functionality and features have steadily grown over the last few years. This year PnP underwent a major update to include some of our PnP user’s requests. The […]
in2Dredging’s extended abstract, entitled ‘Procurement of Dredging Works’, has been approved for the PIANC APAC 2020 conference. This year the conference will be held in Fremantle, Western Australia. The PIANC APAC conference was originally scheduled for mid-June. However, due to the health crisis it had to be postponed to 30 November – 4 December 2020. We […]
Here are a few tips on how you can easily estimate the suction and discharge production of dredging and mining equipment yourself. It is easier than it looks! Taking the time to learn how to do this could save you millions of dollars down the line. Creating your own estimate will also greatly increase your […]
Amid the constant bad news surrounding the coronavirus, it is time for some good news! Almost four years ago, the adventure to build the company in2Dredging Pty Ltd (i2D) began. In the interim years, we have gone from being effectively a sole trader to a real company with Quality and Health Safety & Environment management […]
Insightful Geographic Data Processing: i2D’s new Groundbreaking Service
in2Dredging’s new service is so cutting-edge that we had to create a completely new name for it. Since most of the data used is georeferenced, we felt that a service by the name of “Geographic Data Processing” would cover it well. Despite technological advances, dredging professionals often face unique challenges when processing big datasets originating […]
in2Dredging: A Dredging Consultancy that Understands Mining
In2Dredging’s (i2D) Director and Principal Consultant, Simon Burgmans, has over 20 years’ experience in the dredging industry. He has extensive experience running dredging projects in mining environments, having worked for many large mine operators such as Rio Tinto, FMG and indirectly for Newcrest. Dredging and mining have some things in common. Both, for example, excavate […]
Last year in2Dredging’s consultants were inspired to produce many new and innovative ideas. Therefore, in2Dredging’s Outlook for 2020 is positive. For the new year, in2Dredging has set out the following resolutions: Certify our Quality Management System to ISO 9001 and get recognition for our high-quality standards; Update our existing tools by increasing functionality so as […]
This year’s Central Dredging Association’s (CEDA) flagship conference and exhibition was held in Rotterdam, in conjunction with the Europort Exhibition. in2Dredging (i2D) was one of the presenters at the conference, delivering a well‑received presentation on production estimates and performance monitoring. Topics Discussed at CEDA Dredging Days A main point of focus at the conference this […]
Accurate production estimates are key in determining budgets and schedules for any dredging project. in2Dredging‘s paper for the CEDA Dredging Days Conference aims to assist Clients to recognise optimistic or unrealistic budgets and schedules. This paper deviates from previous papers on this subject in its level of definition. “Production estimates are key to budgets and schedules” Simon Burgmans, […]
A few years ago, in2Dredging developed the Pumps ‘n Pipeline (PnP) estimating tool, which can be used to accurately estimate suction and discharge production. In this post, PnP’s results are introduced chronologically, so as to help describe how suction production rates can be estimated more accurately. PnP has already been explained at a high-level in […]