Discontinuance of Sewage Treatment

MIL-HDBK-1130

b) Discontinuance of Sewage Treatment. When the use of station

sewage treatment facilities may be discontinued, the facilities

should be tagged as secured and bypassed to prevent seepage

water from passing through the plant.

(1) Screen pits and grit chambers should be drained and

cleaned. Screens and comminutors should be cleaned

thoroughly. Screenings should be disposed of in an

approved manner.

(2) Sedimentation tanks should be drained and cleaned; if

these tanks are not of the type drainable by gravity, they

should be filled with clean water and kept oiled during

warm weather to prevent mosquito breeding. Provision

should be made to prevent damage from uplift or freezing.

(3) Trickling filters should be removed from service, and all

piping should be drained to prevent freezing.

(4) Activated sludge and contact aeration-type plants should

be treated as indicated for the sedimentation tanks,

except that porous tubes and plates should be given

special care.

Sludge in sludge digesters should be retained for a

(5)

minimum of five days after plant shutdown to reduce gas

evolution; then the digesters should be opened for

ventilation, and the sludge should be drained to drying

beds. Care should be taken to prevent explosion of gas-

air mixtures in the digesters. Personnel should not be

allowed to enter digestion tanks while they are being

drained or while the danger of asphyxiation or gas

poisoning exists. After a tank has been drained, it

should be cleaned and kept ventilated.

2.5.8

2.5.8.1

General. The Environmental Branch of the cognizant EFD should be

consulted in the technical planning of installation reactivation. It is

especially important that the branch be consulted in establishing

wastewater/sewage treatment system adequacy, operating procedures, and

coordination with regulatory agencies since treatment processes and regulatory

criteria may have changed during the inactivation period. Additionally, the

discharge permit will have to be modified or reissued.

Wastewater Systems. Determination should be made that existing

2.5.8.2

wastewater treatment is adequate in accordance with the latest regulatory

agency criteria. The sewage-treatment plant should be returned to operation.

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