Pond Costs

A key factor in obtaining binding support for aquaculture is development of a sound business plan. The plan needs to demonstrate that the prospective culturist has identified all costs associated with estabhshment of the faciUty and its day-to-day operation. One or more suitable sites should have been identified and the species to be cultured selected before the business plan is submitted. Cost estimates should be verifiable. Having actual bids for a specific task at a specific location eg, pond constmction, well drilling, building constmction, and vehicle costs helps strengthen the business plan. 

The amount of land required varies as well, not only as a function of the amount of production that is anticipated, but also on the type of culture system that is used. It may take several hectares of static culture ponds to produce the same biomass of animals as one modest size raceway through which large volumes of water are constantly flowed. Constmction costs vary from one location to another. Local labor and fuel costs must be factored into the equation. The experience of contractors in building aquaculture facihties is another factor to be considered. 

Jet Aerators. Jet aerators are a cross between the diffused and mechanical aerators. Air and water are pumped separately under the water surface into a mixing chamber and ejected as a jet at the bottom of the tank or pond (Fig. 3f). Jet aerators are suited for deep tanks and have only moderate cost. Disadvantages include high operational costs, limitations caused by tank geometries, and nozzles that can clog. Additionally, they require blowers. 

Because of improved mica processiag operatioas, low cost earthea waste impoundment ponds have been built to store soHd waste and thereby provide for a relatively cheap means of meeting new federal and state environmental laws. 

Total solar salt, NaCl, produced in the world is 90 million tons. Well over that amount of salt is produced in preconcentration ponds as an intermediate step in the production of other chemicals such as potassium chloride. For example, the Dead Sea faciUties produce 40 million tons of salt each year but sell none because of the high cost of transportation to markets. 

Until the 1970s, solar ponds were constmcted and operated as more of an art than a science. Since then, rising land value, environmental conscientiousness, limited space, and rising costs have forced a scientific approach to solar pond optimization, design, and operation to make ponds more productive. 

Where possible, solar salt is replacing vacuum salt because of rising energy costs. For example, in July the 81 x 10 (20,000 acres) of solar ponds... 

Seismic zone basis must be specified for structural design. Soil data is important, especially for cases where extensive use of foundation piling is required with major cost impact. Availability of aggregate or natural pond stabilization materials near the site will not be considered for early cost estimates, but can be kept in mind for future planning if the project is given the green light. 

Land. At this point, it should be possible to determine how much land will be required. Do not forget to include things like holding ponds, environmental buffer area, camp facilities, and rights of way or easements. It may be well to allow some contingency in initial cost estimates for land requirement increases, as more definitive design information becomes available. 

Now you can reconsider the material balance equations by adding those additional factors identified in the previous step. If necessary, estimates of unaccountable losses will have to be calculated. Note that, in the case of a relatively simple manufacturing plant, preparation of a preliminary material-balance system and its refinement (Steps 14 and 15) can usefully be combined. For more-complex P2 assessments, however, two separate steps are likely to be more appropriate. An important rule to remember is that the inputs should ideally equal the outputs - but in practice this will rarely be the case. Some judgment will be required to determine what level of accuracy is acceptable, and we should have an idea as to what the unlikely sources of errors are (e.g., evaporative losses from outside holding ponds may be a materials loss we cannot accurately account for). In the case of high concentrations of hazardous wastes, accurate measurements are needed to develop cost-effective waste-reduction options. It is possible that the material balance for a number of unit operations will need to be repeated. Again, continue to review, refine, and, where necessary, expand your database. The compilation of accurate and comprehensive data is essential for a successful P2 audit and subsequent waste-reduction action plan. Remember - you can t reduce what you don t know is therel... 

R/0 unit Reverse Osmosis Unit for water purification in small aquariums and miniature yard-ponds, utilizes a membrane under pressure to filter dissolved solids and pollutants from the water. Two different filter membranes can be used the CTA (cellulose triacetate) membrane is less expensive, but only works with chlorinated water and removes 50-70% of nitrates, and the TFC membrane, which is more expensive, removes 95% of nitrates, but is ruined by chlorine. R/0 wastes water and a system that cleans 100 gallons a day will cost ft-om 400 to 600 with membrane replacement adding to the cost. A unit that handles 140 gallons a day will cost above 700,00. 

Naslund (2001) investigated a combined system with river water as base load and snow cooling as back up, for an industrial application. The cooling need was 1,500 kW at 5 °C and 1,500 kW at 15 °C, continuously. The needed snow amount was 78,800 ton, stored in a 120 x 100 x 3 m3(L x W x H) pond with water tight asphalt bottom. The estimated investment cost was about 950,000 A. 

This book examines five methods used for concentrate management, namely disposal to surface water, disposal to sewerage, deep well injection, land applications and evaporation ponds. In particular, the book focuses on the design, siting, cost, and environmental impacts of these methods. While these methods are widely practiced in a variety of settings already, there are many limitations that restrict the use of certain disposal options in particular locations. 

The relative increase in cost for surface water disposal, deep well injection, spray irrigation (land applications) and evaporation ponds can be seen in Fig. 3.1. It can be seen that surface water disposal is the cheapest alternative, and it has a strong economy of scale as concentrate volume increases. Deep well injection also has a strong economy of scale, but this method s high construction costs means that it is only becomes feasible with a high enough disposal volume. Evaporation ponds have a poor economy of scale, and it can be seen that the overall cost increases rapidly with volume. This is due to the large amounts of land that are required as the volume of concentrate increases. 

Keywords Costs Environmental concerns Evaporation pond design Evaporation rate Liners Pond area Pond banks Pond depth Social impacts... 

The feasibility of an evaporation pond is determined by the volume of concentrate, the cost of land and the ambient evaporation rate. They are most cost-effective in areas with low rainfall, high evaporation rates, and where large expanses of land are available at low cost (Mickley 2009). This best suits inland desalination plants in regional and remote areas where these conditions can be met. 

---