What is the cost of building a gray water treatment plant

In this article, we will mention how the cost of building a gray water treatment plant is calculated. As we previously mentioned the definition of gray water, the benefits of treating it, and much other valuable information that you will find in this article.

Sewage

It is the product of human use of water after it has been contaminated with organic matter, fats, soap, detergents, hair, bacteria, and other substances.

Wastewater is divided into three sections:

GREY WATER

It is the output of the water used except for toilet water, which is specifically the water of the washbasins, bathing water, laundry water, kitchen water, dishwasher water, and others. However, in this guide, we recommend not connecting the output of kitchen waste water and dishwasher water to the gray water tank because they contain fats, oils, and food residues as it increases processing requirements and costs, and this is consistent with what is stated in German specifications.

Gray water resulting from ablution washbasins in mosques is considered one of the purest types of gray water. Therefore it can be reused in parcel boxes and agriculture, after treating it in simple and economically inexpensive ways. It constitutes a significant resource that can replace part of the fresh water and reduce the total demand for the water.

BLACKWATER

It is the water resulting from the use of latrines, which contains large amounts of organic pollutants resulting from human waste.

SEWAGE WATER

It is a mixture of gray and black water.

Why choose gray water?

• This water constitutes approximately 55-74% of the water used in buildings.
• It contains a low percentage of organic matter and nitrogen pollution (nitrate, nitrite) as well as germs and microbes, and therefore it is easy to deal with during the purification stages.
• Lower treatment costs compared to wastewater.
• Human acceptance of the reuse of that water.
• Recycling and reusing it is not harmful to the environment and health if the specified conditions and specifications are applied.

Processing methods

It requires the establishment of two sewage disposal networks. The first is for the disposal of gray water, which is collected in a ground tank for treatment and then recycled in the parcel and cultivation boxes. The second is for the drainage of black water. Gray water treatment also requires the establishment of a special tank for collecting treated gray water and a feeding network for parcel boxes and agriculture.

Gray water treatment standards and considerations

There are several methods of treatment that the designer can choose the most appropriate according to the nature of the site. Provided that the treated water meets the specific conditions, standards, and requirements, in order to protect public health and the environment. When choosing treatment devices, the following criteria and considerations are taken into account:

• The station’s suitability to the quality of the water to be reused.
• Determining the design capacity of the station to match the actual need for its use.
• The efficiency of the plant to achieve the highest yield of treated water.
• The efficiency of the station to achieve a high quality of water produced in accordance with the specifications of the World Health
• Organization and the Presidency of Meteorology and Environmental Protection.
• Suitability of the station to the location and number of users.
• Low cost, easy to operate and maintain.

General requirements

• Obtaining the necessary license to establish gray water treatment plants from the Ministry of Water and Electricity.
• Not to use treated gray water for other than the purpose designated for that or compatible with the specifications of that water. And if it is used for agriculture, that water should not be used in water sprinklers unless the irrigation is during periods when the irrigated area is empty of people.
• The entity operating the treatment plants shall adhere to operating these plants in accordance with the scientific and technical bases. The instructions are contained in the operation manuals, and conduct periodic analyzes and checks in laboratories accredited by the Ministry of Water and Electricity.
• Do not store treated gray water for more than (24) hours, in order to prevent the proliferation of bacteria and the spread of odors.
• The necessity for the participation of all members of society, governmental and private institutions in raising awareness of the importance of recycling and reusing water, whether it is gray water or treated black water, as one of the non-traditional sources to reduce the overall demand for freshwater needs.

Estimated cost calculation

The cost of building a gray water treatment plant varies based on a number of factors. the most important of which are:

• The production capacity required to operate the plant.
• The cost of preparing the site.

The estimated cost is calculated by the following formula:

The cost of plant consumption per cubic meter = total costs (purification equipment and equipment + site preparation + supply of a special network for recycling + tanks) / production volume x shelf life x 365

Operation and maintenance cost per cubic meter = Operation and maintenance cost (energy + chemicals + spare parts + workers wages) / production volume x 365