According to a legend (http://msc.edu.ph/spc/7lakes/sampalok.html), the lake derived its name from a giant tamarind (sampalok) tree in the garden of a selfishcouple who drove away a fairy disguised as a beggar asking for some fruit.

Hardly an hour after the old man left, there was a thundering noise followed by the cracking of the earth. The next instance, the entire orchard sank into a colossal pit which was eventually filled with water.

Water Quality Monitoring Program

The Laguna Lake Development Authority (LLDA), by virtue of RA 4850, as amended, has the primary responsibility to promote the development of the Laguna de Bay region, while providing for environmental management and control, preservation of the quality of life and ecological systems, and the prevention of undue ecological disturbance, deterioration and pollution.

The LLDA has been conducting regular water quality monitoring with the following objectives:

• To accurately assess the suitability of the lake for all its present and intended beneficial uses;

• To evaluate the impacts of development activities on the lake’s water quality that will serve as important criteria for environmental planning and management.

Routine monitoring programs conducted by LLDA include the Laguna de Bay and its tributaries as well as the Seven Lakes of San Pablo City and Tadlac Lake in Los Banos.  One sampling station was established in Sampaloc lake. During the conduct of the sampling activity, water temperature and dissolved oxygen concentration are measured at the surface (s) and at 2,4,6,10,15,20, and 25 meters depth. A composite water sample from the aforementioned depths is taken for water  quality analysis. The chemical parameters analyzed at the laboratory include pH, total suspended solids (TSS), total dissolved solids (TDS), turbidity, chloride, nitrate, ammonia, inorganic phosphate, biochemical oxygen demand (BOD) and chemical oxygen demand (COD). Zooplankton sample is collected by passing five pails of surface lakewater through a 35-micron mesh-sized  plankton net. Zooplankton sample is preserved in a 10% formalin solution. On the other hand, phytoplankton sample is taken from a gallon of composite sample, placed in small plastic container and preserved with Lugol’s solution. Water transparency

is likewise measured and all the physical observations including weather condition are noted and recorded.

At present, monitoring is conducted during the first (January, February, March) and last quarters (October, November and December) and in June and September.