본 연구는 대수용가 공급체계 전환을 통한 상수관망 운영 에너지 절감방안을 검토하였다. 연구대상지역에 대한 대수용가 공급체계를 SD배수계통에서 JH배수계통으로 전환할 때의 물 공급 가능성과 전력비 절감효과를 분석하고, 능동형 관망관리 방안을 제시하였다. 수리해석 모델을 구축하여 2024년 7월 하절기 최악조건과 물축제 기간을 포함한 시나리오별 분석을 수행하였다. 분석결과, 하절기 최악조건에서는 물 공급 안정성 확보를 위해 SD배수계통 전량공급이 필요하며, 일반조건에서는 JH배수계통을 통한 제한적 공급이 가능한 것으로 나타났다. 전력비 절감효과는 물축제 미포함시 8.1%(SD가압장 57.1%), 물축제 포함시 13.9%(SD가압장 59.0%)로 분석되어 연간 최대 46.2백만원의 절감이 가능한 것으로 산정되었다. 능동형 관망관리 방안으로는 유량제어밸브 설치, 전동제수밸브를 이용한 교축운전, 경부하 시간대 펌프운영 등 3가지 방안을 제시하였다. 본 연구 결과는 대수용가가 포함된 상수관망의 효율적 운영과 에너지 절감을 위한 실무적 지침을 제공할 것으로 기대된다.

상수도 관망은 지하에 매설되어 있어 노후화로 인한 누수, 파손, 부식 등의 문제가 지속적으로 발생하고 있으며, 상수도 관망에서의 노후도 평가와 정비는 수돗물 안전성과 서비스 안정성을 확보하기 위한 중요한 과제 중 하나이다. 본 연구는 상수도 관망에서의 노후도를 효율적으로 평가하기 위해 모든 간접⋅직접평가 인자를 조사하지 않고도 최소한의 주요 평가 인자만으로 실제 직접평가 등급에 근접한 예측 결과를 효율적으로 도출할 수 있는 머신러닝 기반 상태평가 절차와 모델을 제안하였다. 상수관로 상태평가 모델은 랜덤 포레스트와 SHAP 해석기법을 결합한 머신러닝 기반 상태평가 절차를 제안하였으며, 28개 지자체의 강관과 주철관에 대한 간접⋅직접평가 데이터를 대상으로 SHAP-based feature importance 순위가 낮은 평가 인자부터 단계적으로 제거하여 주요 평가 인자를 도출하였다. 결과적으로 강관의 경우 내부 슬라임 분포면적 비율, 수질부식성, 매설연수, 최대 및 외면 부식깊이 비율, 내⋅외면 도장재 손상 비율, 외면 부식 면적 비율, 파손건수, 토양 산화환원전위 및 함수율로 11개의 평가 인자가 주요 인자로 선정되었고, F1 Score는 0.9273이었다. 주철관의 경우 CML 중성화도, 최대 부식깊이 비율, 내부압력, 외부 토압으로 4개의 평가 인자가 주요인자로 선정되었고, F1 Score는 0.6188이었다. 주요 평가 인자만으로도 직접평가 등급에 근접한 예측 결과를 도출할 수 있었으며, 이를 통해 효율적인 상수관로 상태평가를 위한 머신러닝 기법 적용 가능성을 확인할 수 있었다.

상수도 시스템에서의 사고 발생은 사용자들의 물 이용 불편으로 인해 막대한 사회경제적 피해를 초래할 수 있는 위협 요인이며, 따라서 수도사업자들은 수도정비기본계획 등을 통해 상수도 사고를 빠르게 복구하고, 피해 규모를 최소화하기 위한 다양한 노력을 기울이고 있다. 본 연구는 상수도 시스템에서 발생하는 관로사고 상황에 대하여 회복탄력성을 정량적으로 평가하고, 비상급수 방안을 포함한 사고 대응 전략의 효과를 분석하기 위한 평가 모형을 개발하였다. 개발 모형은 시스템의 회복탄력성에 기여하는 다양한 특성들을 반영할 수 있는 시간단위 공급 부족량과 충족률 지표를 통해 회복탄력성을 평가하며, 국내 지방상수도 시스템의 특정 구역을 대상으로 관로사고 시나리오를 모의하여 개발 모형의 적용 효과를 검증하였다. 결과적으로 개발 모형을 통해 비상연계관로, 배수지 충수, 병물 공급 등 비상대응 방안의 효과를 정량적으로 평가하였으며, 이를 통해 시스템의 회복탄력성 향상을 위한 설계 및 운영 전략 수립의 가능성을 확인하였다.

This study would present a risk analysis method to evaluate stable tap water supply in a multi-regional water supply system and propose a measure for the evaluation of the effect of the conjunctive operation of the multi-regional water supply system using this. Judging from the vulnerability for the crisis response of the entire N. multi-regional water supply system, as compared to the result of Scenario 1 in which no conjunctive pipes were operated, it was found that in Scenario 2, in which conjunctive pipes were partially operated, the vulnerability of crisis response decreased by about 30.6%, and as compared to Scenario 3, the vulnerability of crisis response decreased by 86.2%. In setting a plan for stable tap water supply in N multi-regional water supply system, using the estimated value and the method for the evaluation of the vulnerability of crisis response by pipe, by interval and by line, it is judged that this can be utilized as a basis for the judgment of the evaluation of the operation or the additional installation of conjunctive pipes.

The 4th Industry Revolution was advocated by Klaud Schwab who is founder of World Economic Forum at the Davos Forum in 2016, and there are big differences on ICT based 4th Industry revolution in the aspects of speed, scope and impact compared with the 3rd Industry revolution. Creating new industries and values through technology such as internet of things, cloud, big data, and artificial intelligence are included in the meaning of The 4th industry revolution. In this article, the direction of change to water technology in response to the 4th Industry revolution is surveyed. 4G Water Infra should minimize environmental impact under the consideration of sustainable development and advanced technologies. To solve the existing water infra problems, it is common and fundamental that the intake water from nature can be regarded as borrowed from nature and it should be returned to natural state with improved water quality. Government, academic organizations and industries should prepare and collaborate together in order to help our country with outstanding capabilities in infrastructure construction and ICT to lead the 4G water technology development.

The estimation method of economical leakage management target utilized upon planning business for improvement of revenue water ratio in South Korea is presented and applicability of methods developed in this study is assessed through application on site. With a consideration of revenue water ratio in application target area, estimation method of long-term economical leakage management target is applied. Three leakage reduction methods such as replacement of residual aged pipe, leakage investigation and restoration and water pressure management are applied with a consideration of characteristics of site. Due to difficulty of obtaining data, analysis of cost/benefit by leakage reduction methods is performed by applying method of leakages estimation equation among statistical methods. As a result of application, revenue water ratio corresponding to long-term economical leakage management target is 91.6 %.

This study attempts to draw factors for an analysis of the operation effect of a rechlorination facility and autodrain equipment for residual chlorine equalization by installing and operating a rechlorination facility and autodrain equipment in P City and analyzing the practical evaluation method and operation effect. For this purpose, this study selected three indicators for an analysis of the effectiveness of residual chlorine equalization and conducted a comparative analysis before and after the implementation of the residual chlorine equalization. As a result of estimation, ① the reduction of the residual chlorine concentration range from a water treatment plant to the pipe end was 16.0%; ② the total reduction of chlorination input was 18.0%; and ③ the reduction of the generation of disinfection by-products was 19.5%. In addition, this achieved enough residual chlorine equalization in the supply process and shows that it could successfully achieve the economic feasibility of investment in equipment and the reduction of the generation of disinfection by-products. Like this, it is judged that the three indicators suggested in this study will be used sufficiently as indicators of an analysis of the effectiveness of residual chlorine equalization according to the operations of the rechlorination facility and autodrain equipment.

Deposits discharged through the cleaning mainly were cement mortar, bitumen paintings and rust pieces, and fragments of perforation, stones and gravels. Deposits were more removed through swabbing pig cleaning rather than air scouring cleaning on the whole. However, air scouring cleaning were not influenced by the constraint conditions such as a change in the diameter or the presence of the valve in water mains compare to swabbing pig cleaning. So, it was thought that air scouring cleaning might be more favorable to water distribution network cleaning in the future. After the cleaning, water quality including residual chlorine and turbidity also was improved because of the removal of a significant amount of the deposits. Therefore, if the cleaning is continuously and regularly implemented in water mains, it is expected that it will help to recover the reliability and to preserve the health of water quality.

Tuberculation and slime accumulated in water mains play an important role in modifying water quality of drinking water. Therefore, in this study, it was investigated that what materials were accumulated, and what components were included in the tuberculation and slime of water mains. The Various tuberculation and slime sample were collected from the 12 water mains to analyze their physical and chemical properties and crystal structure. As a analysis method, VSS(Volatile suspended solid), SEM(scanning electron microscope), EDS(Energy Dispersive X-ray spectroscope), ICP(Inductively Coupled Plasma Mass Spectrometer) and XRD(X-Ray Diffractomete) were used. The results of analysis on the samples, the representative materials were verified such as iron corrosion products, the fine sand particles generated during backwash, fine particles of activated carbon, aluminum used in coagulation process, and manganese included in raw water.

This study describes a reasonable planning method for water meter replacement which can minimize the metering under-registration for an increasement of revenue water. The increment analysis of real water usage was used to establish a replacement plan. The meter replacement database collected from K City was used as the basis of this analysis. The database included 964 connections of domestic and non-domestic consumers that had their meter replaced by aging at 2011.The result showed that the corelation between unregistered water volume and water meter age was lower than commonly expected where the current criteria of replacement is only water meter age(8 years) excluding the meters older than 13 years. And in the analysis result of water usage for 8 years, the total amount and increment of water usage had a significant effect on unregistered water volume. However the relation was different tendency as a total volume and slope of increment. In case of total water volume was larger than 10,000 , larger than 7,000 and increment of 0.0 ~ -0.3, larger than 6,000 and increment more than -0.3 were analysed to need a replacement because of metering under-registration.