Impact of Wastewater Treatment
Attributes
Medium: Land
Country: Philippines
Analytical Framework(s): Least Cost Concept
Study Date: 2001
Publication Date: 2003
Major Result(s)
| Resource/Environmental Good | PHP, per hectare (2001) |
PHP, per hectare (2014)1 |
USD, per hectare (2014)2 |
|---|---|---|---|
| Increase in sugarcane production due to the application of slops | 23,240.00 | 37,637.64 | 841.52 |
| Value of residual soil fertility | 53,736.00 | 87,026.53 | 1,945.79 |
| Value of residual potassium towards soil fertility | 46,851.00 | 75,876.13 | 1,696.48 |
| Cost of river clean-up (color) of slop-irrigated field | 42,739.00 | 69,216.67 | 1,547.58 |
| Cost of river clean-up (BOD due to run-off) of slop-irrigated field | 88,434.00 | 143,220.63 | 3,202.21 |
| Value of groundwater contamination due to leaching (lower bound) | 8,811.00 | 14,269.59 | 319.05 |
| Value of groundwater contamination due to leaching (upper bound) | 18,098.00 | 29,310.07 | 655.33 |
About the Inflation Adjustment: Prices in Philippines (PHP) changed by 61.95% from 2001 to 2014 (aggregated from annual CPI data), so the study values were multiplied by 1.62 to express them in 2014 prices. The study values could be expressed in any desired year (for example, to 2026) by following the same inflation calculation and being sensitive to directional (forward/backward) aggregations using your own CPI/inflation data.
Study Note: This report provides information on the use of wastes from sugarcane distillation as a resource for improving agricultural productivity. It analyzes various treatment options to find out which brings the most economic, environmental and social benefits to the industry, agriculture and the environment. It finds that when the waste slops are treated optimally, they can be an effective fertilizer and irrigation resource with minimal pollution impact. This not only benefits farmers by increasing yields, but removes a heavy financial burden from the sugarcane processing companies in the form of pollution cleanup costs or fines. The report recommends that the government support this innovative way of reducing pollution.
Study Details
Summary: This study (undertaken in the Philippines and Vietnam) identified and evaluated five waste management alternatives (WMAs) whereby alcohol distilleries can reuse the resulting wastewater (commonly referred to as slops) for irrigation. The five alternatives ranged from no treatment of slops (raw form) to subjecting it to a series of processes before its use as irrigation for sugarcane. The options were analyzed based on the costs and benefits they provided to the distilleries, the farmers, and the environment. Benefits from slops irrigation included the increase in sugarcane production, water availability for the crops, and residual soil fertility after harvest, while the costs were the river pollution due to run off and groundwater pollution due to leaching. Results of the private benefit-cost for the distillery analysis (i.e. from the firms point of view) showed that alternative WMA 4, which uses a combined anaerobic and aerobic treatment with recycling and process improvement before the slops are applied to sugarcane fields, will give the largest net benefit. This result was derived based on the assumption that firms will be made to pay penalty cost for exceeding water quality standards set for wastewater released into the environment. Due to the huge penalty imposed for such violation, it becomes profitable for firms to engage in WMA 4 to avoid penalty payments. This option has the highest net present value and benefit-cost ratio. From society's perspective however, the best option is WMA 2 (anaerobic treatment). The assumption here is that the government has mandated wastewater treatment to firms. As it turned out, there are WMAs that are cheaper to implement compared to the cost of paying the penalty. WMA 2 has the highest net present value: PHP 9.146 million. It also corresponds to the option that has the least cost of reducing BOD load (PHP 1,117/mg/l) and color reduction (PHP 5,029/Pco).
Site Characteristics: The Philippines and Vietnam, at varying levels, are affected by growing urban industries and the consequent rapidly degrading environment. Groundwater contamination limits potable water supply. Efforts to address industrial pollution are greatly dependent on basic understanding of the industries' development and national environmental policies. Transitional economies like Vietnam, for instance, are in the same if not worse situations compared to developing countries like the Philippines, as environmental monitoring bodies are even in a disorganized state. More so, distillery firms are of the small-medium enterprise (SME) types, which are often operating on a cash flow basis and lacking the capacity to adopt environmental initiatives. A simple distillery alone with a 50,000-liter capacity of ethanol per day generates 350,000 liters of wastewater on the average, 22% of which are solid substances. It is expected that the situation will worsen as Vietnam is targeting a one million-tonne sugarcane production this year leading to higher production of molasses and alcohol.
Comments: In Vietnam, field experiments showed the adverse effects of raw slops on standing crops in the first few weeks after application due to high organic matter content, which decomposes in the soil. The canes, however, recovered until harvest time to reach desired growth targets. These results are novel, as previous experiments made use of newly planted crops, not standing crops. While it has been shown that slops have economic value for agricultural use and that its environmental effect can be mitigated, there is still a need for policy adjustments, especially those governing the status of slops as a resource or a waste. In particular, clear standards are needed for slop utilization. The applicability of slops to other crops and other soil types needs to be investigated to arrive at a comprehensive policy for agricultural use of slops.