The city of Tirschenreuth operates a sewage treatment plant for 25,000 population equivalents (size class 4 according to Annex 1 of the Wastewater Ordinance). The wastewater from Tirschenreuth is purified in a mechanical-biological-chemical sewage treatment plant using the impoundment process (SBR process) with separate anaerobic sludge treatment (digestion). The maximum combined wastewater discharge to the sewage treatment plant is Q_M = 135 l/s. The issued elevated permit for the discharge of wastewater into the Waldnaab ends on 31.12.2023.
In the course of preparing the documents for a new water law, it became apparent that the actual load of the sewage treatment plant makes it possible to reduce the expansion size to 20,000 PE. However, the future combined wastewater inflow to the sewage treatment plant must be significantly increased. On the one hand, this increase is necessary in order to meet requirements in the water law of the sewage treatment plant, and on the other hand, the increase makes it possible to make optimum use of the existing volume of combined wastewater treatment plants in the catchment area and to save new construction measures to create further volumes. The future combined wastewater inflow to the sewage treatment plant is 175 l/s.
The demolition of the existing sludge storage hall is part of the planning service.
In detail, the following measures are required at the sewage treatment plant, which are to be carried out in 3 construction phases:
Section 1 - New construction of the computer building
New construction of a computer building with new technical equipment
Dismantling of the existing sludge storage hall
Section 2 - Biological part
Enlargement of the pre-storage tank (conversion of the existing run-off storage tank into a pre-storage tank), expansion of the biological part by a third SBR tank (Vneu = 3,200 m²)
New waste storage tank (V = 650 m³)
Section 3 - Rehabilitation of septic tanks
Rehabilitation of the existing septic tank.
In addition, the various process steps of wastewater treatment and sludge treatment must be examined from the point of view of service life and increasing energy efficiency.
Depending on the planning concept, the implementation takes place in the technically necessary construction phases.
For the project of the new construction of the screening building and extension of the sewage treatment plant, basic services according to HOAI in the area of object planning for engineering structures in accordance with HOAI 2021 Part 3, Section 3, § 41 ff. Work phases LPH 1-9, including special services (component of the screening house LPH 3-9) and specialist planning Structural design in accordance with § 51 and Annex 14, HOAI 2021, LPH 1-6, including special services, as well as specialist planning of technical equipment plant groups 3, 4, 7 and 8 according to § 55 and Annex 15, HOAI 2021, LPH 1-9, without Lph4, including special services (plant group 7 - component Rechenhaus LPH 3-9).
The demolition of the existing sludge storage hall is part of the planning service.
In detail, the following measures are required at the sewage treatment plant, which are to be carried out in 3 construction phases:
Section 1 - New construction of the computer building
New construction of a computer building with new technical equipment
Dismantling of the existing sludge storage hall
Execution period: mid-2023 – end of 2024
Section 2 - Biological part
Enlargement of the pre-accumulator (conversion of the existing drain accumulator to a pre-accumulator),
Expansion of the biological part by a third SBR tank (Vneu = 3,200 m²)
New waste storage tank (V = 650 m³)
Ausführungszeitraum: 2024 – 2027.
Section 3 - Rehabilitation of septic tanks
Rehabilitation of the existing septic tank.
Ausführungszeitraum: 2028 – 2029
The term of the contract II.2.7) includes 4 years warranty/Lph. 9.