This college falls under the category of a ”specified workplace” (a place of business that discharges specified hazardous substances) as defined in the Water Pollution Control Law. The quality of wastewater discharged outside the university is strictly regulated so as not to burden sewage and environmental water.
The frequency and items of effluent measurement are specified in the Water Pollution Prevention Act and the Sewerage Act.
It is obligatory to record the measurement results and report them to the municipality that manages the sewage.
Drainage system
KIT is divided into the Matsugasaki Campus and the Saga Campus.
Drainage at the Matsugasaki Campus is divided into three systems: rainwater, laboratory drainage, and domestic drainage, with all but rainwater flowing into the sewer system. There are two drainage outlets that are subject to the Sewerage Act, one in the eastern campus and one in the western campus. Rainwater is discharged directly into the Takano River.
Wastewater from the Saga Campus is discharged into the sewerage system, and there is one drainage outlet subject to the Sewerage Act.
| items | effluent standard |
|---|---|
| temperature | 45 |
| Potential Hydrogen (pH) | 5～ |
| Biochemical Oxygen Demand (BOD) | 3000 |
| Chemical Oxygen Demand (COD) | 160** |
| Suspended solids (SS) | 3000 |
| N-hexane Extracts (animal and vegetable fats) | 30 |
| Copper | 3 |
| Zinc | 2 |
| Chromium | 2 |
| Phenols | 1 |
| Dissolved iron | 10 |
| Dissolved manganese | 10 |
| Fluorine and its compounds | 8 |
| Nickel | 2 |
| Boron and its compounds | 10 |
| Cadmium and its compounds | 0.03 |
| Cyanide compounds | 0.5 |
| Organic phosphorus compounds (Parathion, Methyl Parathion, Methyl Demeton and EPN only) | 0.5 |
| Lead and its compounds | 1 |
| Hexavalent Chromium | 0.25 |
| Arsenic and its compounds | 0.1 |
| Mercury and its compounds | 0.005 (Internal standard value : 0.002) |
| Alkyl mercury compounds | Not detectable |
| Trichloroethylene | 0.3 |
| Tetrachloroethylene | 0.1 |
| Dichloromethane | 0.2 |
| Carbon Tetrachloride | 0.02 |
| 1, 2-Dichloro ethane | 0.04 |
| 1, 1-Dichloro ethylene | 0.2 |
| cis-1, 2-Dichloro ethylene | 0.4 |
| 1, 1, 1-Trichloro ethane | 3 |
| 1, 1, 2-Trichloro ethane | 0.06 |
| 1, 3-Dichloropropene | 0.02 |
| Chloroform | 0.6* |
| trance-1, 2-Dichloro ethylene | 0.4* |
| 1, 2-Dichloropropane | 0.6* |
| p-Dichlorobenzene | 3* |
| Benzene | 0.1 |
| Selenium and its compounds | 0.1 |
| Toluene | 6* |
| Xylene | 4* |
| 1,4-Dioxane | 0.5 |
Unit from BOD to 1,4-dioxane is mg/l.
* indicates control target value.
** indicates effluent standard by the Prime Minister’s Ordinance.
Monitoring and Recording
The Sewerage Act requires that the pH and temperature of wastewater be measured at least once a day.
A continuous measurement device has been installed at the west point of the Matsugasaki Campus to continuously measure pH and temperature. These values are sent to the Center for Environmental Science, which manages them on a PC, and an alarm is turned on at the Center if the pH and temperature values exceed the range of 5-9 and 0-50°C, respectively.
Since only domestic wastewater flows into the east point of the Matsugasaki Campus and the water volume is low, pH and temperature are measured by manual sampling once a week.
At Saga Campus, pH and temperature are continuously measured at the laboratory drain of the Drosophila Genetic Resource Center, and these values are displayed and recorded at the control room in the center.
The maintenance and inspection of the continuous measurement devices at the west point of the Matsugasaki Campus and the Saga Campus drainage are outsourced, and the devices are inspected and calibrated once a month.
Measurement
For other items specified in the Sewerage Act, wastewater from all three locations is sampled twice a month and analyzed at the Center for Environmental Science.
In addition, subcontracted analysis of wastewater is conducted five to six times a year.
Material which burden on drainage
In recent years, chemical substances have been used in a variety of materials, and the cause of water quality abnormalities is not limited to chemical laboratories. In addition to experimental drainage, there are also some non-laboratory and office wastes that are used and affect the drainage. Some paints and adhesives contain organic solvents, and some of these solvents are regulated by the Sewerage Act. Some dyes, paints, and pigments contain highly toxic metals, and these metals are regulated items in wastewater. Be sure to check the composition of the materials used, and do not wash or dispose of large quantities at a time.
The following table shows examples of materials containing toxic chemicals that are also used in non-experimental systems.
| Materials | Chemical substances |
|---|---|
| Coating material | Toluene, xylene*, ethyl acetate, methyl alcohol, isopropyl alcohol, etc. |
| Dye | Chromium, iron |
| Paint, Pigment | Cadmium yellow and cadmium red (cadmium), silver white (lead), vermillion (mercury), chrome yellow and orange chrome (chrome), and chrome yellow and orange chrome (chrome) Vermillion (mercury), Chrome Yellow and Orange Chrome (chromium), Cobalt Violet and Emerald Green (arsenic), Selenium Red (selenium), etc. |
| Glue | Dichloromethane (commercially available acrylic resin adhesive) |
| Washing agent | Alkalis such as sodium hydroxide, acids such as phosphoric acid, etc. |