Unlike, for example, sand and dolomite, groundwater is considered a mineral resource of national significance.

A groundwater deposit passport must be obtained if it is planned to extract more than 100 m^³ of groundwater per day from one or more boreholes. It is important to note that the validity of the passport is time-limited, and the expiration date must be monitored. In addition, the results of groundwater monitoring must be regularly reviewed — for instance, changes in the chemical composition of the water may lead to a revision of the issued passport.

Several institutions are involved in the issuance of a groundwater deposit passport — the State Environmental Service, the Latvian Environment, Geology and Meteorology Centre (LEGMC), and the Health Inspectorate.

License for Hydrogeological Investigation

To obtain the necessary data for preparing a groundwater deposit passport, a hydrogeological investigation must be carried out. Prior to that, a license must be obtained from the State Environmental Service. The license is issued in accordance with Section 7, Paragraph 1, Subparagraph 1, and Section 10, Paragraph 1, Subparagraph 3(e) of the Law on Subterranean Depths.

To obtain a license for hydrogeological investigation, an application must be submitted to the State Environmental Service in accordance with Paragraph 22 of Cabinet Regulation No. 696. The application must also include the annexes specified in Paragraph 23 of the same Regulation, including information on staff qualifications and the technical equipment intended for the work, as well as a work programme coordinated with the client.

Hydrological Investigation and Report

The hydrogeological investigation and the preparation of the investigation report must be carried out in accordance with Chapter 2.2 of Cabinet Regulation No. 570.

During the investigation, the following is determined:

• A description of the geological structure and hydrogeological conditions of the investigated area;
• Justification for the selection of the prospective water-bearing horizon;
• The groundwater level and the permissible drawdown of the groundwater level;
• The exploitable reserves of groundwater;
• The parameters and configuration of the deposit protection zones;
• A description of the groundwater quality status (based on chemical and bacteriological analyses of water samples) and the compliance of the water quality with drinking water safety requirements.

The prepared hydrogeological investigation report must be submitted to the Latvian Environment, Geology and Meteorology Centre (LVĢMC) for approval of the groundwater reserves.

After the Latvian Environment, Geology and Meteorology Centre (LEGMC) has reviewed the protection zone calculations and approved the groundwater reserves, the groundwater deposit protection zones must be coordinated with the Health Inspectorate.