(1) In order to ensure sewage is completely and safely disposed of, a work camp must:

(a) connect to a public sewage system meeting the requirements of Title 17, chapter 38, subchapter 1 of the Administrative Rules of Montana; or

(b) if the work camp is utilized by no more than 24 persons or no more than 9 families daily during all except 59 or fewer days of the calendar year, including day workers and residents; and an adequate public sewage system is not available; utilize a non-public system which meets the construction and operation standards contained in either of department of environmental quality circulars #84-10 or #13 or which is designed by an engineer registered in Montana and, to the satisfaction of the department and local health officer, offers sanitary protection equivalent to those circulars.

(2) Liquid wastes from sinks, showers, or baths may not be allowed to accumulate on the ground surface and must be discharged into the sewage treatment and disposal system serving the work camp or into an alternate system approved by the department and local health officer.

(3) A sewage treatment and disposal system must be replaced or repaired if any of the following conditions occur:

(a) The system refuses to accept sewage effluent at the rate of application.

(b) Sewage effluent seeps from, or ponds on or around, the system.

(c) Effluent from the sewage treatment and disposal system contaminates a potable water supply or state waters.

(d) The sewage system is subjected to mechanical failure, including electrical outage or collapse or breakage of a septic tank, lead line, or drainfield line.

(4) An extension, alteration, or replacement of any sewage treatment and disposal system must be made in accordance with the standards set forth in this rule.

(5) Any sewer service lateral must be constructed as follows:

(a) The lateral must be water tight at all points and tested for that quality by filling with water, by another equivalent test, or, in the case of a lateral which is required by ARM 37.111.615 to be constructed of schedule 40 PVC, schedule ABS, or standard weight case iron pipe, by testing under pressure of at least a 10-foot head of water for a minimum of 15 minutes, or other equivalent test.

(b) Pipe size must be a minimum of 4 inches in diameter.

(c) The lateral must be sloped to maintain a 2-foot per second flow velocity (1.2% slope for 4-inch line) .

(6) If facilities for individual sewer connections to trailers are provided, they must meet the following requirements:

(a) The sewer riser pipe must:

(i) have a 4-inch diameter;

(ii) be so located on the trailer space that a sewer connection to the trailer drain outlet will approximate a vertical position; and

(iii) be separated from the water riser by at least 6 feet at finished grade.

(b) Surface drainage must be diverted away from the riser.

(c) Provisions must be made for plugging or capping the sewer riser pipe with a tamper resistant cap having an air tight seal whenever a trailer does not occupy the space.

(7) A sewer connection between a trailer and a sewer riser must:

(a) have a nominal inside diameter of at least 3 inches;

(b) be sloped at least 1/4 inch per foot;

(c) consist of one line only, without any branch fitting;

(d) have watertight joints;

(e) be constructed of corrosion resistant, non-absorbent, durable material with a smooth inner surface, except that flex hose may be used for making a sewer connection whenever the connection will be made for 14 days or less.

(8) A work camp which provides trailer space for self-contained trailers must also provide one sanitary station meeting the standards in (9) below for every 100 trailer spaces, or fraction thereof, which lack individual sewer risers, except in the following cases:

(a) Whenever a sanitary station is available for public use on a full-time basis within a reasonable distance from the work camp.

(b) Whenever installation of a sanitary station is not feasible due to lack of electricity, water under pressure, or other similar considerations beyond the control of the work camp operator.

(9) A sanitary station must have:

(a) a sewer riser pipe at least four inches in diameter which is:

(i) connected to the work camp sewage system;

(ii) surrounded at the inlet end by a concrete apron at least four feet square sloped to the drain;

(iii) provided with a self-closing hinged cover.

(b) a water outlet equipped with anti-back-siphoning devices and connected to the work camp water supply system to permit periodic washdown of the immediately adjacent area; and

(c) a sign stating that the water is unsafe for drinking.

(10) If any living units are not provided with individual toilet facilities, central toilet facilities must be located within 300 feet of all sleeping quarters lacking such individual toilets and provided in the ratio of one toilet for every 10 persons or fraction thereof needing them.

(11) The department hereby adopts and incorporates by reference Title 17, chapter 38, subchapter 1 of the Administrative Rules of Montana, which sets construction standards for sewage systems; and the following department publications setting construction and operation standards for specific types of sewage systems:

(a) Department of environmental quality circular #84-10, "Sewers and Sewage Treatment for Multi-Family and Non-Residential Buildings";

(b) Department of environmental quality circular #13, "The Sanitary Pit Privy". Copies of ARM Title 17, chapter 38, subchapter 1, and circulars #84-10 and #13 may be obtained from the Department of Public Health and Human Services, Health Policy and Services Division, Food and Consumer Safety Section, 1400 Broadway, P.O. Box 202951, Helena, Montana 59620-2951.