Environmental impact assessment

6.3 Impacts of the Operation Phase

6.3.1 Impact on Physical Systems

During the period of treatment facility systems operation, negative impact is expected during routine repairs that will be connected with noise, dust and combustion products spread in the atmospheric air. The mentioned impact is short-term and will not be significant.

Possible emergency situations on sewage collectors can have significant impact on the environment.

6.3.2 Impact on Biological System

The fact that there are no sewage treatment facilities in the Mtskheta municipality and waste-water flows into the river directly without cleaning causes negative environmental and sanitary conditions. This imposes the river pollution and spreading of infectious diseases.

The discharge parameters of untreated sewage into the river are shown in the table below:

Table 6.3.2.1

#	Ingredients	Existing concentration	Unit
	BOD5 (biological oxygen demand)	60	g/PE/d
	COD (chemical oxygen demand)	120	g/PE/d
	Suspended solids	70	g/PE/d
	BOD-concentration	171	mg/l
	COD-concentration	343	mg/l
	Filterable solids	200	mg/l
	Kjeldahl-Nitrogen concentration	34	mg/l

On the bases of the existing situation it was decided to construct waste water treatment plant that will ensure improvement of discharged sewage quality. Namely, the ecology and sanitary conditions of the river and its surroundings will become better due to the technological scheme, in addition, activities to avoid impact and emergency situation management activities will be implemented.

It will decrease the risk of river pollution and spreading of infectious diseases.

After treatment the waste water, the discharge parameters into the river are shown in the table below:

Table 6.3.2.2

#	Ingredients	Allowed concentration mg/l	Maximum permissible discharge g/h
1.	Weighted particles	30	7125
2.	BODtotal	6	1425
3.	COD	30	7125
4.	Nitrogen Ammonium	0,39	93
5.	Nitrates (NO3)	45	10688
6.	Nitrites(NO2)	3,3	784
7.	Polyphosphates (PO4)	3,5	831

According to following indexes, positive impact is accepted to the aquatic biology of the river during the lifetime of the project.

There is no negative impact on biological systems expected during the period of sewage systems operation. The impact is mainly expected on the aquatic biodiversity, in case if for some reason untreated waste waters get to the river.

6.2.3 Evaluation of impact on social system

During the period of sewage systems operation, negative impact is expected during routine repairs that could mean temporary disturbance of the population. Also in case of incorrect waste management (such as sludge, accumulated in a treatment facility and its incorrect management, i. e. violation of terms and time of disposal from the area) it is expected that the population will suffer from noxious odors.

Significant positive social impact is anticipated in case of implementation of the Project, namely:

• 
  Prevention of service-sanitary sewage discharge to surface water objects without treatment.
  
• 
  Implementation of the sewage systems project provides stable development of resort infrastructure that is of big importance for social-economical development of the city and the region.