When it comes to cost accounting for sewage treatment projects, it is not as easy as simply calculating how many pipes were bought or how many workers were hired. Don't just focus on treating sewage, there are many ways here. You have to be careful from start to finish, otherwise it's easy to waste money and the project may not meet the standards in the end.
Firstly, we need to start from the beginning of the project, which is the preparatory stage. At this point, many people may not pay much attention to the cost, but it actually accounts for a considerable proportion. Do you think that to build a sewage treatment plant, you must first know the sewage situation in this area? We need to send someone to investigate and see how many residents and factories are nearby, how much sewage can be discharged every day, what is in the sewage - whether it is more domestic sewage or industrial wastewater, and whether there are any difficult to treat chemicals inside. The survey fee and water sample testing fee are indispensable. Sometimes, in order to obtain accurate data, multiple measurements are required, and the cost gradually increases.
And then, having data alone is not enough, we need to ask the design institute to come up with a plan. The treatment processes vary greatly depending on the different sewage conditions. For example, in treating domestic sewage, the activated sludge process may be sufficient; But if industrial wastewater containing heavy metals is to be treated, the process will be much more complex and the cost will be high. The design institute needs to draw and budget based on the actual situation, and this design fee is also a considerable expense, usually calculated according to a certain proportion of the total project cost. The larger the project, the higher the design fee.
Once the plan is finalized, it's time to spend money on actual equipment and material procurement. This part can be said to be the "big part" of the cost. Sewage treatment cannot be separated from various equipment, such as grid machines, used to remove large garbage from sewage; Sedimentation tank, allowing sediment in sewage to settle down; There are also aeration equipment in the biochemical reaction tank, as well as final disinfection equipment such as ultraviolet disinfection or chlorine dioxide disinfection devices. The quality and brand of these devices directly affect the price. Imported devices may be more than twice as expensive as domestic ones, but sometimes imported devices have good stability and easy maintenance in the later stage, which depends on the budget and requirements of the project.
The material aspect cannot be ignored either. Building a pond requires the use of steel bars and cement, laying pipes requires the use of PVC pipes or steel pipes, as well as small components such as cables and valves, which add up to a considerable amount. Moreover, material prices are also affected by market fluctuations. For example, if steel prices increase, the material cost of the entire project will have to be raised. Therefore, when purchasing, it is necessary to seize the opportunity or sign long-term contracts with suppliers to lock in prices.
The next step is the cost of the construction phase. This part mainly includes labor costs and machinery rental fees. Excavating foundations, building ponds, and installing equipment all require workers, such as bricklayers, electricians, and welders. The wages for different occupations vary, and the longer the construction period, the higher the labor cost. Sometimes when there is a rush to meet the deadline, overtime pay must be calculated for the workers. In terms of machinery, large equipment such as excavators and cranes require a daily rental fee of several thousand yuan. If the construction site is complex and special machinery is needed, the cost will be even higher.
During construction, there may also be some unexpected situations, such as digging underground pipelines while excavating the foundation, which requires work to be stopped and the route to be changed, resulting in additional relocation costs; Or on rainy days, when there is water accumulation on the construction site, it is necessary to pump water, lay soil, and spend an extra amount of money. These 'unforeseeable expenses' may initially be included in the budget, but when they actually occur, they are often more than estimated.
The completion of the project is not considered complete, and it still needs to be debugged and run for a period of time, during which the cost must also be included. During debugging, various chemicals need to be added, such as nutrient agents during the biochemical treatment stage to promote better growth of microorganisms; A flocculant may need to be added to the sedimentation tank to allow impurities to settle faster. The dosage of these drugs is calculated based on the amount of sewage, and it will cost a lot of money in a day. Moreover, during the debugging phase, technical personnel need to monitor and observe the operation of the equipment and changes in water quality, which is also a labor cost.
Finally, there is also the cost of later operation and maintenance, which, although not included in the construction cost, must be considered when calculating the total cost. For example, the equipment needs regular maintenance and replacement of parts, such as the aeration head becoming clogged after prolonged use and requiring replacement; The chain of the grid machine is prone to wear and needs to be repaired regularly. There are also electricity bills. The water pumps and aeration equipment in sewage treatment plants are major power consumers, and a medium-sized sewage treatment plant may have a monthly electricity bill of several hundred thousand yuan. In addition, specialized operators need to be hired to be responsible for daily inspections and water quality monitoring, and their salaries also need to be included.
At first glance, the cost accounting of sewage treatment projects is really interrelated, from preliminary investigation to later operation and maintenance, every link needs to be carefully monitored. Sometimes, in order to control costs, trade-offs are made in equipment selection or construction plans are optimized, but the premise is that it cannot affect the treatment effect. After all, the ultimate goal of sewage treatment projects is to ensure that sewage is discharged in compliance with standards and protect the water environment. If we cut corners in order to save money and the final treated water does not meet standards, the money spent in the early stages will be in vain, and we will have to rework, which is even less cost-effective.
So, when calculating the cost of a sewage treatment project, it's like peeling an onion, calculating layer by layer. We need to consider both visible accounts and possible hidden accounts, so that we can spend money wisely and build an economical and practical sewage treatment project.
