Wastewater Treatment Plant Design and Rehabilitation
Regional Wastewater System Evaluations
When additional customer cities are added to a regional wastewater facility, or when the choice is between a plant expansion or resurrecting a mothballed WWTP, determining the best course of action can be daunting. 我们的团队最近在两个独立的区域系统中协助一个主要的区域污水服务提供商做出此类决策. In both cases, 我们协调了流量和降雨量监测，以及相关的入流/入渗分析，并制定了未来平均和峰值流量情景. Population and flow projections were considered, as was the cost of returning old facilities to service. In one of these systems, the owner ultimately elected to expand an existing treatment facility from 1.5 MGD to 3.0 MGD; Perkins Engineering Consultants, Inc. (PECI), served as prime consultant for design of the plant expansion, which is now in full operation. In another, PECI conducted a subsequent study evaluating adding two new customers in the regional system.
Nutrient Removal Evaluation and Aeration System Improvements
PECI评估了33 MGD区域污水处理厂的生物营养物去除(BNR)工艺配置. Historical operating and additional sampling data were collected, organized and analyzed to define design conditions, including diurnal fluctuations. Unit processes, 确定了三种BNR工艺的设备尺寸和配置，并为每种配置制定了初步布局. Life cycle cost comparisons were prepared for each of the three BNR alternatives.
The first 13.9 MGD phase was constructed at a cost $4.5 million. 改进包括用高速涡轮鼓风机取代现有的三台多级离心鼓风机(6),000 scfm each) and addition of a new CMU electrical building. Baffle walls, anaerobic and anoxic zone submersible mixers, mixed liquor recycle pumps and piping, and new effluent gates were added to six existing Aeration Basins.
Regional Treatment Plant Clarifier and Thickener Rehabilitation
PECI担任分包顾问，负责为服务于20多个城市的152 MGD处理设施设计机械和工艺改进. This multifaceted project involved a large design team, in which PECI led design efforts for:
New primary clarifier scum concentrators;
Mechanism replacement on four 75' x 275' rectangular clarifiers;
Mechanism replacement on circular gravity thickeners:
Aluminum truss supported flat covers on the gravity thickeners; and
Corrosion and coatings repairs on multiple structures.
The overall project bid at $23 million and was completed in 2015.
Nutrient Removal Evaluation
PECI确定并评估了16 MGD城市污水处理厂的营养物去除工艺配置. Unit processes, 确定了化学除磷和生物除营养物(BNR)工艺的配置和初步成本. Three alternatives for BNR were evaluated as part of the project. Capital and operating costs for one alternative for BNR, Anaerobic/Anoxic/Aerobic, along with upgrading the aeration system, 还确定了固体处理上清液流的化学除磷和侧流处理.
Regional Treatment Plant Hydraulic Improvements
PECI serving as a subconsultant to another firm, 负责确定需要的水力泄压改进，以使这个152 mgd的区域工厂能够更好地将12个二级澄清池的流量分配到32个低水头污水过滤器, 其中一些被放弃，而另一些则通过布媒体改造获得了重大的能力升级. Two relief tunnels were identified and designed. 第一个工程涉及一条相对较短但复杂的84英寸减压隧道，将两个分离的澄清池的污水槽连接起来. This pipeline was partially installed by open cut, but due to electrical duct banks and other large utilities in the vicinity, specific portions had to be installed by tunneling in tight, confined operating plant areas and beneath roadways.
PECI has designed multiple improvements to a 10 MGD plant serving two cities in north Texas. PECI为进水升降机站指定了一套带有有机介质的生物气味控制系统(生物洗涤器). 这使得业主可以减少位于固体处理大楼的现有化学洗涤器的使用，并导致大量的化学和能源成本. To reduce corrosion in the existing electrical room, PECI specified a positive pressurization unit to pressurize the room with scrubbed air. 此外，PECI用新的散装储罐重新设计了现有的化学储存区，以容纳满载的氢氧化钠和次氯酸钠.
Primary and Secondary Clarifier Rehabilitation
PECI担任主要顾问，负责为德克萨斯州北部多个城市服务的48mgd区域废水系统中的四个大型主澄清池和四个二级澄清池进行主要腐蚀修复的设计. The project involved assessment and repair of corrosion damage to concrete structures, rehabilitation of four 135-foot aluminum low-profile basin covers, weir and baffle replacements and skimming system rehabilitation. 还包括对主澄清池洗涤和通风系统有效性的评估.
Blower and Aeration System Upgrade
PECI担任主要设计顾问，协助德克萨斯州北部一个主要城市更新其24 MGD污水处理厂的活性污泥工艺. The project included installation of new high speed turbo aeration blowers, air piping, and fine bubble membrane diffusers. The existing aeration system included four multistage centrifugal blowers. The project was placed in service at a cost of $2.6 million.
Snail Collection and Slurry Pumping System
As part of a larger plant rehabilitation project, PECI designed a special settling basin to capture snails from a trickling filter process. 设计了一个泵送系统，将蜗牛装载的泥浆移动到分类器中，这样蜗牛就可以存放在滚装容器中，以便运离现场. The project significantly reduced snail accumulation in downstream basins.
Screen and Conveyor System Replacement
PECI协助加兰德市更换了该市24 mgd罗利特河污水处理厂头厂大楼的筛选和输送设备. Equipment installation was performed by City personnel.
Plant-Wide Rehabilitation Improvements
PECI被委托评估和优先考虑整个24 MGD污水处理厂的修复需求，该处理厂服务于多个城市. The treatment facilities had been constructed and expanded under numerous contracts, with many facilities over 40 years of age. Corrosion and structural deterioration was a concern in a number of areas.
PECI在两个建设项目中担任主要顾问，负责最优先的改进项目的详细设计. 这些项目包括对工厂内一些覆盖的混凝土结构进行广泛的腐蚀修复, drainage improvements inside the plant’s dewatering building, addition of a 5,000 CFM bioscrubber for odor control, replacement of the plant’s aging return and waste activated sludge piping and distribution system, rehabilitation of approximately 3,500 square yards of in-plant paving surfaces, and addition of access and security improvements. Full-span truss supported aluminum covers were added to the plant's primary clarifiers, screens were replaced, and major electrical gear was rehabilitated.
Plant Rehabilitation Needs Assessment
PECI担任主要顾问，负责对这个152mgd的区域污水处理设施进行全厂范围的评估和修复需求的优先排序. The effort included review of the age, criticality, and condition of dozens of major process units, along with development of projected costs for rehabilitation. Coordination with multiple consultant teams was required. 评价确定了建议在6至10年内总计约6 000万美元的厂内修复.
Wastewater Treatment Plant Domes and Mixing System Addition
Perkins Engineering Consultants, Inc. 协助谢尔曼市增加了圆顶，以覆盖三个90英尺高的最终澄清池，用于控制藻类. 该项目还包括为工厂的潮湿天气储存设施增加一个喷射混合系统. The project was placed in service at a cost of $1.4 million.
Vehicle Washing Facility for Biosolids Transport Trucks
PECI设计了一个拖车洗涤设施，用于清洁区域处置设施中清空的生物固体拖车. PECI evaluated possible options and develop cost estimates for the following two key facets of design:
Truck wash location; and
Water clarity and disposal.
Four truck wash locations were evaluated. Options for increasing water clarity included chemical coagulation, electro-coagulation and water softening. The disposal facility is not served by an existing sewerage system and recycle of flows was considered.
Wastewater Treatment Plant for Retail Development
PECI, serving as a subconsultant to another firm, was responsible for drafting technical specifications for the preselection of equipment for a 0.014 MGD package wastewater treatment plant in Hayes County, Texas. PECI led pre-selection of a plant equipment manufacturer, then preparation of plans and specifications for the construction of the treatment system. PECI是污水储存罐的主要设计单位，该储存罐将作为地下灌溉系统的储存罐. PECI will be assisting with construction services and plan submittals to four state, regional and local agencies for approval.
Truck Weigh Scale Evaluation
Working with multiple departments, PECI评估了几个污水处理厂的现场称重选择，以帮助我们的客户保持符合当地的要求, state and federal transportation rules. Reviewing container loading and hauling operations, analyzing sludge processing data, and current documentation, PECI evaluated various weighing options including portable scales, steel deck scales, low speed weighing scales, electronic or hydraulic load cells on the existing container systems, and overhauling the existing sludge conveying and receiving equipment with cake storage systems. Conceptual layouts and preliminary costs were developed for each of the options presented. In addition, 其中包括对业务程序的修改，这些修改可以在没有资本支出的情况下进行，以保持对运输规则的遵守.
Regional Treatment Plant Effluent Filter Rehabilitation
PECI作为主要顾问，为24 MGD污水处理厂改造现有的旅行桥砂过滤器和布过滤器. The project consists of modifying the filter basins to accommodate the proposed filters, installing new influent weir gates, drain and yard piping modifications, and a structural canopy to cover the filter basins. The project site is subject to potential flooding, so additional design elements such as shut off switches, equipment enclosures, and raised control panels were implemented to protect the equipment should flooding events occur. This project is currently under construction and expected to be finished in first quarter 2022.