Orange County NC Website
Browse       Search
• <br /> 5 <br /> 1 B. ALTERNATIVE SEWAGE TREATMENT SYSTEMS <br /> 2 This item was presented to provide and summarize available <br /> 3 information on the reliability of alternative sewage treatment <br /> 4 technology. <br /> 5 County Engineer Paul Thames presented information about the <br /> 6 Hazen & Sawyer Report on Alternative Treatment Systems. He distributed <br /> 7 a handout which listed a case study summary on alternative treatment <br /> 8 systems as well as conclusions and recommendations from the report. <br /> 9 Paul Thames explained that a small wastewater treatment <br /> 10 system, in terms of the report, range in size from 4, 000gpd to <br /> 11 150,000gpd. This is the permitting size which is sometimes larger than <br /> 12 the size that is actually needed. <br /> 13 In answer to a question from Commissioner Gordon, Thames <br /> 14 explained that there are two kinds of discharge systems -- package <br /> 15 plants and septic tank/sand filter systems. The septic tank/sand filter <br /> 16 system has a conventional gravity septic tank which discharges into a <br /> 17 large container filled with sand. The liquid waste filters through the <br /> 18 sand and solids are removed. It also receives some additional treatment <br /> 19 from microbiological activity. The package treatment plant is a <br /> 20 prefabricated unit which uses many of the same treatment processes as <br /> 21 do larger municipal treatment plants such as Hillsborough's, OWASA's or <br /> 22 Durham's. <br /> 23 A discharging system discharges from a single point to the <br /> 24 surface waters. A nondischarging system can be spray irrigation onto <br /> 25 the surface of the ground or be injected by subsurface means. He <br /> 26 explained how the conventional septic system discharges into a <br /> 27 nitrification field. <br /> 28 Commissioner Halkiotis referred to a list of possible <br /> 29 problems which lead to violations of the operating permit and asked <br /> 30 about the validity of the statement that the technology of alternative <br /> 31 waste treatment processes is technically sound. Thames explained that <br /> 32 when a system is designed, the ultimate use of the system should be kept <br /> 33 in mind and that insuring the design is carried out as intended requires <br /> 34 that the designer monitor the construction to be sure it is constructed <br /> 35 correctly. What has happened is that the systems have been installed <br /> 36 without the designer monitoring construction. After the system was paid <br /> 37 for, the original design engineer was never involved again. The system <br /> 38 construction was turned over to the developer or contractor who had <br /> 39 other priorities for spending their money. The procedure now is that <br /> 40 all permits issued by the Division of Environmental Management require <br /> 41 systems to be designed by a professional engineer who must certify that <br /> 42 the system is built in accordance with the approved plans. In terms of <br /> 43 operation and maintenance, DEM looks at these systems once a year and <br /> 44 sometimes they don't even do that. On many systems when the maintenance <br /> 45 is neglected, they begin to fail. <br /> 46 Health Director Dan Reimer explained the proposed Monitoring <br /> 47 Program for alternative and conventional waste treatment and disposal <br /> 48 systems. He explained, with the use of overhead transparencies, seven <br /> 49 types of systems. He listed some of the responsibilities and the <br /> 50 department who has the authority for each of these seven systems and the <br /> 51 authority they recommend. <br /> 52 <br />