Notation rules for ① Simple hot springs

■If the temperature of the spring is 25℃ or higher, there are no other conditions for naming the spring, and the total dissolved matter (excluding gaseous substances) are less than 1,000 mg/kg, the spring is classified as “Simple hot springs”. If the spring is alkaline or weak alkaline, it is named “Alkaline simple hot springs” or “Weak alkaline simple hot springs”.

Notation rules for ② Saline springs ③ Hydrogen carbonate springs ④ Sulfate springs

■For those 1,000 mg/kg or more, the main component of anions is described in the spring quality name.

■Cations and anions are listed in this order and connected by “ー” or “–” (dash).

【Example】If the main component of the cation is “sodium ion” and the main component of the anion is “chloride ion”
→ “sodium―chloride springs”

【Example】If the main component of the cation is “magnesium ion” and the main component of the anion is “hydrogen carbonate ion”
→ “magnesium―hydrogen carbonate springs”

【Example】If the main component of the cation is “calcium ion” and the main component of the anion is “sulfate ion”
→ “calcium―sulfate springs”

■If the 'mval%' (milli valent percentage) of both cations and anions are 20% or more, the substances are listed in descending order of content. If there are multiple special components, cations, and anions, they are separated by “.” (middle black, middle dot) (in the case of Japanese notation). When written in English, special components and cations are separated by “,” (comma) and anions by “/” or “／” (slash).
【Example】sodium, calcium, magnesium―hydrogen carbonate/chloride springs

■The components reflected in the spring quality name as cations are as follows.
sodium ions → sodium　　　　magnesium ions → magnesium
calcium ions → calcium　　　　aluminum ions → aluminum
iron(Ⅱ,Ⅲ) ions → iron(Ⅱ,Ⅲ)
hydrogen → hydrogen　※When the name of spring quality is “Acidic springs” and there is no other component with 20 mval% or more, it is described.

Notation rules for Hot springs containing special components ⑤Carbon dioxide springs ⑥Iron containing springs ⑦Acidic springs ⑧Iodine containing springs ⑨Sulfur springs ⑩Radioactive springs

■If the special components are the specified value or more, they are described as follows.
If the “free carbon dioxide” content is 1,000 mg/kg or more → “carbon dioxide springs”
If the total iron ion content is 20 mg/kg or more → “iron containing springs”
If the hydrogen ion content is 1 mg/kg or more → “acidic springs”
If the iodide ion content is 10 mg/kg or more → “iodine containing springs”
If the total sulfur content is 2 mg/kg or more → “sulfur springs”
If the radon content is 8.25 mache/kg or more → “weak radioactive springs” / 50 mache/kg or more → “radioactive springs”

■If the special components (free carbon dioxide, total iron ions, hydrogen ions, iodide ions, total sulfur, and radon) are at the specified value or more, they are described at the beginning of the spring quality name.
【Example】sulfur containing ― sodium―chloride springs
If two or more special components are contained, they are described as follows. And the order of the special components is, in principle, as follows.
1. hydrogen ion (cation) → acidic
2. total sulfur[HS^ー＋ S₂O₃^2ー＋ H₂S] → sulfur containing
3. free carbon dioxide → carbon dioxide containing
4. radon → radioactive containing
5. total iron ions [Fe²⁺+Fe³⁺] → iron containing
6. iodide ions → iodine containing

■【Example】acidic, sulfur containing ― sodium ― sulfate springs
weak radioactive containing, iron (Ⅱ,Ⅲ) ― magnesium ― sulfate springs
carbon dioxide containing, iron (Ⅱ,Ⅲ) ― simple cold mineral springs
sulfur containing, weak radioactive ― alkaline simple hot springs

■If it is not “Saline springs”, and the dissolved components are less than 1,000 mg/kg while the special components are equal to or more than the specified value, it is described as follows.
【Example】simple carbon dioxide springs
【Example】simple iron containing springs
【Example】simple acidic springs
【Example】simple iodine containing springs
【Example】simple sulfur springs
【Example】simple radioactive springs / simple weak radioactive springs

Notation rules for spring temperature

■Substances classified under the “Hot Springs Act” are contained at or above the specified value, and if the spring temperature is 25℃ or higher, it is called a “hot spring”;
if the temperature is less than 25℃, it is called a “cold mineral spring”.
【Example】If the temperature is 25℃ or higher･･･“sodium chloride spring” or “sodium chloride hot spring”.
※Other examples include “hydrogen carbonate springs” or “hydrogen carbonate hot springs” and “sulfate springs” or “sulfate hot springs” but most of them do not use the “hot” word.
If the temperature of the spring needs to be emphasized, “hot” word to be added.
【Example】If the temperature is less than 25℃･･･“calcium sulfate cold mineral springs”

■In the “classification by osmotic pressure, hydrogen ion concentration/pH, and spring temperature,” which is written alongside the spring name, the spring temperature should be classified as follows.
Less than 25℃・・・cold mineral spring
25℃ or higher to less than 34℃・・・low temperature spring
34℃ or higher to less than 42℃・・・hot spring
42℃ or higher・・・high temperature spring

Notation rules for exceptions

■If it is a hot spring under the “Hot Springs Act” but is not classified as a therapeutic hot spring (when the metasilicic acid content is more than the specified value for a hot spring), it should be described as follows.↓
→It qualifies as a hot spring according to the metasilicic acid (H₂SiO₃) section in the appendix to Article 2 of the “Hot Springs Act”. However, it does not qualify as a therapeutic hot spring, and there is no name of the spring quality.
→It qualifies as a “hot spring (containing metasilicic acid)” under Article 2 of the “Hot Springs Act”.

※D: If the temperature is less than 25℃, it is called a “cold mineral spring”. The name “sulfate springs” can also be used here.
※E: “Sulfur spring” can be classified into “Sulfur type” and “Hydrogen Sulfide type”, but only “Hydrogen Sulfide type” is indicated at the end.
※F, G and H: classification should be written together with the spring name.
※H: “spring temperature” of 42℃ or higher is indicated as “High temperature spring”.

※D: “hot springs” can be changed to “springs”.
※B, C: If there is more than one substance with 20 mval% or more of cations and anions, they are listed in descending order of abundance.
※H: If the temperature is 34℃ or higher to 42℃, it should be described as “Hot spring”.

※If the temperature of the spring is 25℃ or higher and the total dissolved substances (excluding gaseous substances) is less than 1,000 mg/kg, the spring is classified as “Simple hot springs”.
※If the spring is alkaline, the name of the spring is described as “Alkaline simple hot springs”.
※H: If the “spring temperature” is 25℃ or higher to less than 34℃, the spring is described as a “Low temperature spring”.

※D: If the temperature of the spring is less than 25℃, it is described as a “cold mineral spring”.
※H: If the “spring temperature” is less than 25℃, it is described as a “cold mineral spring” instead of a “low temperature spring”.