(1) No matter the use of any technology, technology, water treatment after its water quality to meet the national standard of living water.
(2) Technical safety reliability principle. At present, although there are many kinds of water treatment technology and equipment in our country, we should choose the most advanced and the most safe and reliable equipment from many technical theories and equipments.
(3) Minimum operating cost principle of equipment. In view of the remote and underdeveloped areas of our country, if the running cost of water treatment equipment is too high, it is beyond the affordability of the local people, even if the construction of water treatment projects is completed, the local people cannot afford to lose the construction because of the high equipment running cost. Therefore, in the water treatment equipment engineering construction must take into account the cost of equipment operation.
(4) The principle of easy management. In view of the relative shortage of equipment technology managers in the underdeveloped areas, the equipment management and maintenance requirements are as simple and easy to manage as possible. If the equipment management technology requirements are too high, beyond the capacity of the equipment technology managers, the normal operation and management of equipment will not be guaranteed.