Technical Building Regulation STR 2.02.04:2004 – Water Abstraction and Treatment Provisions
The Statybos techninis reglamentas STR 2.02.04:2004, titled Vandens ėmimas, vandenruoša. Pagrindinės nuostatos (Water Abstraction and Treatment. Main Provisions), is a mandatory technical regulation issued by the Ministry of Environment of the Republic of Lithuania. Approved by Order No. D1-156 on March 31, 2004, this document became effective on July 4, 2004. It forms part of the national legal framework for construction, specifically governing the design and installation of systems for human drinking water supply.
The regulation establishes the essential requirements for water treatment systems, including vandens ėmyklos (water abstraction facilities) and vandens ruošyklos (water treatment plants). Its scope covers drinking water preparation systems for groundwater and surface water sources. It defines technical parameters for mechanical resistance, fire safety, hygiene, health and environmental protection, as well as safe use and noise control. The document specifically excludes building-internal plumbing, external distribution networks, and water intended for specialized industrial processes such as cooling or specific technological cycles.
The text is structured into sections covering general provisions, terminology, essential structural requirements, and specific technical rules for different types of abstraction sources. It provides a framework for architects and engineers to ensure the longevity and safety of water infrastructure while maintaining the quality of the water extracted and treated for public consumption.
Essential Requirements and Safety Standards
The regulation mandates that water abstraction and treatment systems must meet specific performance criteria to ensure structural stability and water quality throughout their economic life. These requirements are categorized into several technical domains:
- Mechanical Resistance and Stability (§7.3.1): Systems must be designed so that loads do not cause collapse, impermissible deformations, or damage to nearby buildings.
- Fire Safety (§7.3.2): Materials used in above-ground fire-fighting water lines and other installations must be non-combustible or protected from ignition.
- Hygiene, Health, and Environment (§7.3.3): Requirements to prevent contamination from sewage, chemical pollutants, or microbial growth. This includes the establishment of Sanitarinės apsaugos zonos (Sanitary Protection Zones).
- Safe Usage (§7.3.4): Design must prevent accidents such as slips, falls, or explosions during maintenance and operation.
Groundwater Abstraction Facilities
The document provides detailed technical rules for extracting groundwater using various types of wells and boreholes. Selection depends on local geological conditions and water quality.
- Boreholes (Gręžiniai): Must be designed with specific casing diameters based on pump capacity and include measuring devices for water levels and samples.
- Shaft Wells (Šachtiniai šuliniai): Used for shallow, non-pressure aquifers up to 30 meters deep. They require a reverse filter and a protective 2-meter wide stone or concrete pavement around the top.
- Radial Intakes (Spindulinės ėmyklos): Horizontal filter pipes installed radially from a central shaft, typically used in high-yield aquifers near surface water bodies.
- Well Decommissioning: Boreholes that are no longer suitable for use must be decommissioned by plugging (tamponavimas) to prevent pollution of underground resources.
Surface Water Intake Categories
Surface water intakes are classified into three categories based on the required reliability of the water supply to the consumers:
- Category I: High reliability; supply interruptions due to accidents must not exceed 10 minutes.
- Category II: Medium reliability; interruptions are permitted for up to 6 hours or up to 10 days for a 30% reduction in supply.
- Category III: Lower reliability; total interruption allowed for up to 24 hours.
Intake structures must include measures to protect against biological fouling, ice formation, and sediment accumulation. The document specifies that intakes should be located upstream from waste outfalls and intensive economic zones.
Water Treatment and Recirculating Systems
The regulation defines standards for common treatment processes such as nugeležinimas (iron removal), minkštinimas (softening), and nukenksminimas (disinfection).
- Disinfection: May utilize chlorine, ozone, or UV radiation. Contact times in reservoirs must be at least 30 minutes for chlorine.
- Iron and Manganese Removal: Selection of technology depends on the concentration of minerals and the presence of organic matter.
- Recirculating Systems: Covers industrial cooling water systems, including requirements for aušintuvai (coolers/towers) and pursliniai baseinai (spray ponds).
Frequently Asked Questions
What is the mandatory contact time for water disinfection with chlorine?
According to §277, the reaction time for water disinfection with chlorine reagents must be no less than 30 minutes in the contact reservoirs.
How are surface water intakes categorized for reliability?
They are divided into three categories: Category I (max 10 min interruption), Category II (max 6 hours interruption), and Category III (max 24 hours interruption) as per §110.
What is the required depth for shaft wells according to this regulation?
Shaft wells (šachtiniai šuliniai) are typically installed in shallow, non-pressure aquifers at depths up to 30 meters (§69).
Are building internal plumbing systems covered by STR 2.02.04:2004?
No, the regulation specifically excludes building engineering systems for plumbing and hot water (§3.1, §3.3).
What is a 'Vandenspara' in the context of this document?
As defined in §10.14, a vandenspara is a water-impermeable layer located above or below an aquifer with a filtration coefficient K ≤ 10⁻⁴ m³/d.
Who must comply with the provisions of STR 2.02.04:2004?
The regulation is mandatory for all construction participants, public administration entities, and owners or users of engineering networks (§5).
