Project I. Public Utility Retchitsa Vodokanal

10.2. Project I.  Public Utility Retchitsa Vodokanal

10.2.1. Project Description

The population of the town of Retchitsa is 68 thousand people, including 46.9 thousand people in the municipal residential sector connected to the sewage system.  The remaining population are associated with private individual developments which are serviced independently.  Residential and industrial effluents undergo treatment at the municipal treatment facilities.

Wastewater treatment facilities of the town of Retchitsa are located in the village of Bronnoye of Retchitsa Rayon Gomel Oblast on the right bank of the Dnipro River, 5 km away from the eastern part of the town.  The designed productivity of the wastewater treatment facilities is 25000 m³/day.  The hydrolysis plant discharges to the wastewater treatment facilities up to 17 thousand m³/day.  In addition to the hydrolysis plant, the wastewater treatment facilities treat discharges from all enterprises, establishments and organizations of the town as well as residential wastewater.  Apart from the hydrolytic plant, none of the industrial enterprises of Retchitsa pre-treat their effluents.  Wastewater is conveyed to the wastewater treatment facilities through two main lines.  Currently, the daily volume of wastewater directed to the wastewater treatment facilities comprises about 20 thousand m³/day.  On average industrial effluents, mainly from chemical, timber, woodworking, food, light and other industries make up 1/3 of total volume of wastewater.

The wastewater treatment facilities are designed in accordance with conventional treatment schemes, including mechanical and biological treatment in aeration tanks.  The wastewater treatment facilities include:

- Installations of mechanical treatment – inlet chamber, gratings constructions, sand catcher, preaerator and 4 presettling tanks.

- Installations of biological treatment – 4 three-corridor sections of aeration tanks and 4 final settling tanks.

- Installations for after treatment of sewage water – 4 successive sheets of biological ponds.

- Installations for processing of sediment and excess active sludge – 2 sludge tanks with total area of 10.4 hectares.

The four sheets of biological ponds have become silted and have become impossible to clean because of the lack of a bypass pipe and successively linked sheets.  At present, due to emergency conditions, the maximum allowable concentration of treated effluent does not meet the discharge criteria. The treatment efficiency for BOD is 88% and for suspended solids is 66%.  The discharge of insufficiently treated effluent takes place continuously through a single combined surface outlet.

For quality control purposes, the laboratory of the wastewater treatment facility carries out systematic monitoring of the wastewater treatment facilities for performance efficiency and water quality in the Dnipro River in compliance with an approved schedule, and in the volume agreed upon with local inspecting organizations.  The schedule has been approved by the Gomel Committee of Natural Resources and Environmental Protection; monitoring is carried out two times a month at the place of discharge to the Dnipro River.  Composite samples are taken weekly.

Table 10.1 : Concentration of Contaminants in the Dnipro River in 2001 (mg/l)

Table 10.2 : Concentration of Contaminants in the Dnipro River in 2002 (mg/l)

In 1984, the “Belkommunproekt” Institute developed a programme for the reconstruction and extension of wastewater treatment facilities, with a specified increase in productive capacity of up to 60 thousand m³/day.  Construction commenced in 1989. According to the programme, construction should have been completed in a 4-year period.  However, as a result of insufficient financing, construction is still going on up to the present day.

10.2.2. Mitigation Measures

To solve the problems of effluent post-treatment and ensure reduction in pollution level in the Dnipro Basin water, it is necessary to realize the environmental measures presented in Table 10.3.

Table 10.3 : Environmental/Mitigation Measures for Retchitsa Vodokanal for 5 years

  1 $US = 1865 roubles

10.2.3. Investment Programme

The provision of post-treatment measures for effluent, a program to utilize excess sludge, the replacement of the emergency automatic flow tank and other water-protective measures require 11350389 thousand Byelorussian roubles, or $US 6086 thousand for the first 5 years.

10.2.4 Feasibility Analysis

A feasibility analysis of the water-protective measures was carried out by comparing the economic results of these measures with the costs required for their realization.

For Retchitsa Vodokanal, the following input data was used:

- investment required for reconstruction and expansion of the wastewater treatment facilities - $US 6086 thousand;

- operational (current, annual) costs of the newly created facilities - $US 83.7 thousand

The respective input data are presented in Annexes 1-3 and used in the calculations for Table 10.4.

Table 10.4 : Reduction in Total Mass of Mono-Pollutant to be Achieved in Pollution with Effluent from Municipal Treatment Facilities within Five Years

Calculation of the reduced mass of pollution reduction by mono-polluters (М):

М = ∑ D_i V_i = 12988.6 c. t. (see Table 10.4)

Calculated per year М₁ = 2597.7 c. t.

D_a = 275 * 1.75 * 2598 = $US 1250 thousand

Calculation of increment of lost financial benefit (I):

I is assumed in professional judgment as 10% of D_a

I = $US 125.0 thousand

Calculation of the economic result of the water-protective measures

E_r = 1250 + 125 = $US 1375 thousand

Calculation of the reduced costs (∆C)

∆C = Е * К + Т_с

Е = 0.12

К = $US 6086 thousand

Т_c - operational (current, annualized) costs of wastewater treatment for the commissioned environmental facilities – $US 83.7 thousand.

∆C  = (0.12 * 6086)+83.7 = $US 814 thousand

Calculation of the net annualized economic effect

DU = E_r - DC = 1375 – 814.0 = $US 561 thousand

The payback period (Т) for the investment into water-protective measures is:

Т = К / ∆U = $6086/$561 = 10.8 years

Based on environmental design practices, the threshold of effective return for investments into wastewater treatment facilities is 14 years.  Therefore, the suggested project with an estimated payback period of 10.8 years is economically effective and justified.

Next: Project II. Public Utility Minskvodokanal (PU Minskvodokanal)

Previous: Introduction