Laguna de Bay
From Wikipedia, the free encyclopedia
| Laguna de Bay | |
|---|---|
 |
|
| Coordinates | |
| Lake type | Crater Lake (theorized)/ Rift Lake |
| Primary outflows | Pasig River (via Napindan Channel) |
| Basin countries | CALABARZON, Philippines |
| Max length | 41 km |
| Max width | 36 km |
| Surface area | 911.36 to 949 km² |
| Average depth | 2.8 m |
| Max depth | 20 m (Diablo pass) |
| Shore length1 | 220 km |
| Surface elevation | less 2 m |
| Islands | Talim Island, Wonder Island |
| Settlements | Metropolitan Manila and the Provinces of Laguna and Rizal |
| 1 Shore length is an imprecise measure which may not be standardized for this article. | |
Laguna de Bay is the largest lake in the Philippines and the 2nd largest inland freshwater lake in Southeast Asia after Lake Toba in Sumatra, Indonesia. It is located in the island of Luzon between the provinces of Laguna to the south and Rizal to the north. Metro Manila lies on its western shore. Its surface area is 949 square kilometers and has an average depth of only about 2 meters. The lake is shaped like a stylized 'W', with two peninsulas jutting out from the northern shore. Laguna de Bay drains to Manila Bay through the Pasig River. The lake is filled with fish pens installed by fishermen who regularly fish there.
There are two islands in the lake, Talim Island, which is a part of the towns of Binangonan and Cardona in Rizal province, Wonder Island in Calamba City which is privately owned and developed into a posh resort.
Laguna de Bay is the Old Spanish term for "Lake of Bay"; Bay (pronounced as bä'ï) is a town in Laguna province. Pulilan is the prehispanic name of the lake according to the 1613 Vocabulario de Lengua Tagala printed in Pila, Laguna. In Philippine prehistory, Laguna Lake or Laguna de Bay was known as Pulilan. Thus the name Pulilan Kasumuran or Laguna de Bay water source.
Contents |
[edit] Facts about the lake
The Laguna Lake is a large shallow freshwater body in the heart of Luzon Island, Philippines with an aggregate area of 91,136 hectares and a shoreline of 220 kilometers. The lake is fed by 45,000 square kilometers of catchment areas and its twenty one major tributaries. It is considered to be the second largest inland body of water in Southeast Asia, after Indonesia’s Lake Toba in Sumatra (Guerrero & Calpe, 1998). It is bordered by the province of Laguna in the east, west and southwest, the province of Rizal in the north to northeast, and Taguig, Pateros, Pasig and Marikina (all of which are cities and municipalities in Metropolitan Manila) in the northwest. The lake has an average depth of 2.8 meters and its excess water is discharged through the Pasig river. The southern and eastern portions of Metro Manila occupy a huge portion of its watershed (Gonzales, 1987; Guerrero & Calpe, 1998).
Currently, the lake serves as a multipurpose resource. It is a navigational lane for passenger boats, source of water for a nearby hydroelectric power plant, food support for the growing duck industry, aquaculture, recreation, fishery, flood control, source of irrigation water and a “virtual” cistern for domestic, agricultural and industrial effluents (Gonzales, 1987). Because of its importance in the development of the Laguna de Bay Region , unlike in other lakes in the country, its water quality and general condition are closely monitored (Department of Environment and Natural Resources, 1996). This important water resource has been greatly affected by development pressures like population growth, rapid industrialization, and resources allocation (Batu, 1996).
Government data showed that about sixty percent of the estimated 8.4 million people residing in the Laguna de Bay Region discharge their solid and liquid wastes indirectly to the lake through its tributaries. A large percentage of these wastes are mainly agricultural while the rest are either domestic or industrial (DENR, 1997). According to DENR (1997), domestic and industrial wastes contribute almost equally at thirty percent each. Meanwhile, agricultural wastes take up the remaining forty percent. In a recent sensitivity waste load model ran by the Laguna Lake Development Authority’s (LLDA) Integrated Water Resources Management (IWRM) Division, it revealed that 70 percent of Biochemical Oxygen Demand (BOD) loadings came from households, 19 percent from industries, 19 percent from industries, and 11 percent came from land run-off or erosion (LLDA, 2005).
As far as industries and factories are concerned, there are about 1,481 and is expected to increase over time (Guerrero & Calpe, 1998). Of the said figure, about 695 have wastewater treatment facilities. Despite this, the lake is absorbing huge amounts of pollution from these industries in the forms of discharges of industrial cooling water, toxic spills from barges and transport operations and hazardous chemicals like lead, mercury, aluminum and cyanide (Sly, 1984). Based from the said figure, sixty five percent are classified as “pollutive” industries.
The hastened agricultural modernization throughout the region took its toll on the lake. This paved the way for massive and intensified use of chemical based fertilizers and pesticides whose residues eventually find their way to the lake basin. These chemicals induce rapid algal growth in the area that depleted oxygen levels in the water. Hence, oxygen available to the lake is being used up thereby depleting the lake of available oxygen for the fish causing massive fish kills (Solidarity for People’s Power, 1992). As far as domestic wastes are concerned, around ten percent of the 4,100 metric tons of waste generated by residents of Metro Manila are dumped into the lake. As reported by the now defunct Metropolitan Manila Waterworks and Sewerage System (MWSS), only 15 percent of the residents in the area have an effective waste disposal system. Moreover, around 85 percent of the families living along the shoreline do not have toilets (SPP, 1992; Batu, 1996).
Because of the problems facing and threatening the potential of the lake, the then President Ferdinand Marcos signed into law Republic Act (RA) 4850 otherwise known as the law creating LLDA. The LLDA is the main agency tasked to oversee the programs that aimed to develop and protect the Laguna Lake. Though it started as a mere quasi–government agency with regulatory and proprietary functions, its charter was strengthened by Presidential Decree (PD) 817 in 1975 and by Executive Order (EO) 927 in 1983 to include environmental protection and jurisdiction over the surface waters of the lake basin. In 1993, by virtue of the devolution, the administrative supervision of the LLDA was transferred to the DENR by EO 149 (LLDA, 1994).
[edit] Protection and Conservation the Laguna Lake
The Environmental User Fee System
To realize the objectives of the creation of LLDA, the agency implemented policies to curb down the possibility of stressing the lake’s assimilative capacity . The most recent policy was the Environmental User Fee System (EUFS). The EUFS was implemented by virtue of LLDA Board Resolution 22 in 1996. The objective of the policy was to “…(reduce) the pollution loading in to the Laguna de Bay by enjoining all discharges of liquid wastes to internalize the cost of environmental degradation…”. Formally, the said board resolution aptly defined the EUFS as a “market–based” policy instrument aimed at reducing the pollution loading in the lake. As such, companies found to have unusually high concentration of pollutants in their emissions, need to pay fines or lake “user – fees”.
The system is a market – based instrument that encourages companies to invest in and operate pollution prevention and/or abatement systems within their establishment. Applying the "Polluter Pay Principle", the system effects direct accountability for damage inflicted on the integrity of Laguna de Bay Region thereby encouraging individuals and business establishments to internalize into their decision-making process the environmental impacts of their day-to-day activities. The EUFS covers all enterprises within the administrative jurisdiction of LLDA that discharge wastewater in the Laguna de Bay system. These include commercial and industrial establishments; agro-based industries and establishments (such as swine farms and slaughterhouses); clustered dwellings (i.e. residential subdivisions); and domestic households (LLDA, 2001).
Under the EUFS, a firm is required to secure a discharge permit which is renewed on an annual basis at the LLDA. The discharge permit effectively allows the firm to discharge its wastewater to the lake or through its main tributaries. The discharge permit gives the establishment a legal right to dispose their waste water in the Laguna de Bay Region. Wastewater is basically, sewage, storm water and water used for various purposes around the community, including firms. Wastewater can either be domestic or non domestic. Domestic wastewater includes black water, or wastewater from toilets, and gray water, which is wastewater from all sources except toilets. Black water and gray water have different characteristics, but both contain pollutants and disease-causing agents that require monitoring. Non domestic wastewater are generated by offices, businesses, department stores, restaurants, schools, hospitals, farms, manufacturers, and other commercial, industrial, and institutional entities. Storm water is a nonresidential source and carries trash and other pollutants from streets, as well as pesticides and fertilizers from yards and fields (Taylor, et al, 2005).
According to the Clean Water Act of 2004, the DENR (through the LLDA) shall “implement a wastewater charge system in all management areas including the Laguna Lake region and Regional Industrial Centers through the collection of wastewater charges/fees. The system shall be established on the basis of payment to the government for discharging wastewater into the water bodies. Wastewater charges shall be established taking into consideration the following: a) to provide strong economic inducement for polluters to modify their production or management processes or to invest in pollution control technology in order to reduce the amount of water pollutants generated; b) to cover the cost of administering water quality management or improvement programs, including the cost of administering the discharge permitting and water pollution charge system; c) reflect damages caused by water pollution on the surrounding environment, including the cost of rehabilitation; d) type of pollutant; e) classification of the receiving water body; and f) other special attributes of the water body”.
The technical aspect regarding the quality of wastewater is given in DENR Administrative Order 1990-35. The order defines the critical water parameters’ value versus the classification of the body of water (e.g. lake or river). Discharge permits are issued by the LLDA only if the wastewater being discharged complied with the said order.
The EUF is a fee that is paid for the amount of pollution that is discharged into the tributary rivers within the Laguna de Bay Region. It is composed of a fixed fee and a variable fee. The fixed fee covers the administrative cost implementing the Environmental Users Fee System and is based on the volume of wastewater that is discharged.
According to LLDA Board Resolution 33, as amended, the fixed fee is different for those firms which discharge wastewater without or with heavy metals. The term heavy metal refers to any metallic chemical element that has a relatively high density and is toxic or poisonous at low concentrations. Examples of heavy metals include mercury (Hg), cadmium (Cd), arsenic (As), chromium (Cr), thallium (Tl), and lead (Pb).
Wastewater without heavy metals:
| Fee | Volume of Wastewater Discharge |
|---|---|
| Php 24,000 | More than 150 cubic meters per day |
| Php 16,000 | Between 30 and 150 cubic meters per day |
| Php 8,000 | Less than 30 cubic meters per day |
Wastewater with heavy metals:
| Fee | Volume of Wastewater Discharge |
|---|---|
| Php 12,000 | Less than 150 cubic meters per day |
| Php 24,000 | More than 150 cubic meters per day |
The fixed fee also depends on the volume of wastewater discharged. Table 4 summarizes the fixed fees depending on the volume of wastewater discharge and the presence of heavy metals. For a firm that discharges wastewater without heavy metals, the fee would be 24,000 pesos if the discharge is more than 150 cubic meters per day, 16,000 pesos if the discharge is between 30 to 150 cubic meters per day and 8,000 pesos if the discharge volume is less than 30 cubic meters per day. Those firms that discharge wastewater with heavy metals, on the other hand, pay higher fixed fees. The fee would be 12,000 pesos for a firm that discharge less than 150 cubic meters of wastewater with heavy metals per day and 24,000 if the discharge is more than 150 cubic meters per day.
The variable fee, on the other hand, is calculated with the reference to the BOD5 loading as well as to the volume and concentration of the wastewater being discharged. According to the same policy, the variable fees is 30 pesos per kilogram of total BOD5 when the BOD concentration is less than 50 milligrams per liter and 30 pesos per kilogram of total BOD5 when the BOD5 concentration is greater that 50 milligrams per liter.
[edit] References
See the talk page for the list of references.
