SITE VISIT REPORT
Town of Lyons
Eco-Machine™ Sustainable Wastewater Treatment System
Prepared for
Town of Lyons
Prepared by:
John TODD ECOLOGICAL Design, Inc.
P.O. BOX 497 / 1 SCHOOL STREET WOODS HOLE, MA 02543
508.548.2545 508.540.3962 fax TODDECOLOGICAL.COM
10 Dec 2011
Project Background
The Town of Lyons is looking at different options to meet its wastewater treatment goal in the next couple decades, and the ecological approach of John Todd Ecological Design, Inc. (JTED) is being considered. JTED has over 30 years experience with natural wastewater treatment design, general aquatic management, and project supervision. Many of JTED designed systems are zero discharge.
In fall 2011, the town of Lyons invited JTED to initiate a preliminary assessment of the opportunities for sustainable wastewater management.
The objectives of wastewater management at Lyons are:
1)Resolve the operational issues of existing treatment facility and secure the safe and effective operation of existing facility before upgrade facility is built
2)Secure long term wastewater treatment capacity at 350,000 gpd, either by building a new plant, upgrading the existing plant, or connecting to the sewage treatment system in Longmont
3)Integrate wastewater management with sustainable development whenever possible
The Preliminary Site Visit
On October 17, 2011, Jonathan Todd, president and principal designer of JTED, and Hui Lin, project engineer, paid a trip to the town of Lyons. The JTED team worked with the town board, the town staff and engineer, the Sustainable Future Commission, JVA, Honeywell, and concerned citizens, to discuss the design for the new wastewater treatment system.
Existing Treatment Facility
The existing sewer system is a combination of vitrified clay and SDR-35 PVC. The peak I&I factor is 2.0.
The existing plant, built in 1976, is an activated sludge process, with 300,000 gpd design capacity. The current average flow rate is 134,000 gpd. Sludge produced in the process, 3,000 gpd in flow rate and 150 pounds per day by dry weight, is stabilized by an aerobic digestion unit, de-watered by a centrifugal unit and a drying bed, prior to shipping to landfill.
The system is working as designed, but the odor from the aerobic sludge digester is more than noticeable. Also the system is going beyond the designed lifespan, and thus an upgrade of wastewater treatment is being considered. The upgrade considerations include a new capacity threshold to be 385,000 gpd.
Upgrade Options
So far, the town has been presented three possible options in dealing with the wastewater treatment problems:
1.Connecting to the sewer at the nearby City of Longmont, and get treatment by paying a usage fee;
2.Renovating the existing facility;
3.Building a new facility at one of the locations that we visited.
No matter which option is chosen, the town will need to maintain or renovate the existing facility, before the replacement is completed. JTED can see multiple ways in which the existing system can be retrofitted to meet the existing demand but also suggests a completely new system that takes advantage of the low cost Eco-Machine principles and natural processing.
Assessment 1: Outsourcing Wastewater Treatment
In JTED’s opinion, connecting to the sewer in City of Longmont is not the most sustainable option. The reasons are:
1) The high capital cost and unpredictable usage fee
2) Lack of control to the treatment process and resources recovery
Assessment 2: The Existing Facility
The Sewer System
The current overall I&I factor of the sewer is 2.0, which makes the I&I factor for the clay pipe sections roughly 4.0. The treatment plant is thus receiving a high peak flow during storm event, which could be a potential risk as the town grows and the treatment plant ages. Although it is not the most prominent issue, repairing the collection system is an absolutely necessary step towards any sustainable water management. The failure of the existing system is one of the causes of the I&I during storm event stressing an already marginal system. The collection system during non-storm events is likely causing sewage to leakage from the collection systems into Lyons ground water and could even result in mixing with surface waters that could result in a human health hazard. Because the sewer collection system is so intrinsic to the long term sustainable hydrology we have put it first on the list of suggested actions to be taken by the Town of Lyons in it’s charge of a long term sewage management mandate.
We suggest that the town hire a local engineering firm to access the I&I problem, which appears to be from a multitude of causes mostly a result of aging and deteriorated collection system ranging from clay pipe to failed PVC components. JTED would suggest that they use STEP and STEG collection system to minimize the cost to the town.
See more about STEP and STEG systems at the following link: limnoterragroup.com/sfi/step system
Septic tank effluent systems have the advantage over conventional system in that they are more cost effective to install and result in lower solids and I&I.
Finally we suggest that local restaurants and commercial facilities be made to comply with grease trap maintenance protocols that will not continue to stress the system and add to the bulking solids. There are many sustainable technologies available for the maintenance of grease traps including products from Hydros.
Upgrade of the Existing Plant
It would be a key task in any step going forward to integrate the work of Honeywell, JVA and the “As Built” drawings of the existing plant and to look at the alternatives to existing operations.
1) Sludge Control
Sludge dewatering and disposal currently represents a significant part of the operational cost and labor requirement.
JTED and Hydros, Inc. have been working together for decades to minimize sludge production in wastewater treatment process using biological measures. As a result, ecological systems designed and built by JTED produce minimal sludge in the headwork and no sludge in the aerobic process. For the existing facility of Lyons, there are several ways that we can work to reduce the sludge disposal cost. There is opportunity on site to reconfigure the effluent flow through the existing plant and use both conventional and natural processes to move operations away from activated sludge and towards an ecologically sequenced system that would perform both with less sludge production and lower odors:
a. By using toilet injectors which supplement the pipeline and treatment work with selected beneficial bacteria, break down carbonaceous compounds in the wastewater before it reaches the treatment plant;
b. Conduct upstream biochemical survey, and minimize the discharge of grease and other high strength wastewater
c. Conduct biological audit for the current plant operations, make sure that sludge is being wasted at an optimal ratio and at an optimal timing. This greatly influences the amount and settleability of wastewater sludge;
d. Supplement the treatment plant microbiological community with selected high efficiency digesting bacteria, which promotes aerobic digestion of the sludge, even before it reaches the aerobic digester;
e. Integrate bio diverse, plant based components proven in studies to reduce solids by 70%
f. Replace drying beds with reed beds to expedite the dewatering of sludge.
g. Convert from activated sludge to an ecologically sequenced system with ecological components.
Summary of sludge control
The primary challenges to both sludge management, operations and odor issues at the existing plant are converting from an activated sludge operation to an ecologically sequence WWT plant without an interruption in operations. Our preliminary assessment shows this is a viable alternative. This approach would require a combination of conventional and natural components. A full Process Flow Report would need to be completed to ascertain the parameters of the site and what could be achieved there using the exiting and additional infrastructure. Further study may conclude that full treatment of the wastewater is viable on site.
Figure 1. The Existing Treatment Facility
2) Odor Control
The major source of odor in the current operation is the aerobic digestion of sludge, produced by the activated sludge. By reducing the sludge, the odor source would be reduced.
Retrofitting the aerobic digester could control the remaining odor. There are two possible ways of odor control that JTED had successful experience with:
a. Biological venting system – cover the aerobic digester with planted ecological filter that absorbs and break down various chemicals that cause the odor;
b. Physiochemical scrubbing system – cover the aerobic digester and collect vented air, scrub the air with specialized material which will be selected after determining the type of chemicals that are causing the odor.
3) Retrofitting the Process with Ecological Principles
By incorporating ecological principles, the existing plant could be renovated at a relatively low cost to operate in a reliable and productive way.
Upon a thorough feasibility study, JTED could potentially conduct one or several of the following:
a. Reducing chemical and electricity use in the treatment plant;
b. Enhancing the treatment process and improve effluent quality, to meet more stringent regulations;
c. Introducing vivid ecology to the treatment plant and greatly enhance the appearance;
d. Adding educational components to the existing plant.
Assessment 3: Locations for Upgrade
JTED and Lyons team visited four locations: 1) the existing plant, 2) the Cemex Plant, 3) the Eastern Corridor (for a decentralized on site system only), and 4) the abandoned Longmont water treatment plant.
At both Cemex Plant and the abandoned Longmont water treatment plant, we visited two different sites respectively, but at this point we have not noticed significant difference between the two sites in one location from our technical perspectives.
Cemex
The two empty lots at the Cemex plants have similar properties, according to the preliminary site visit. Because of the space available and readily available natural resources, JTED sees this site as a candidate for future integrated park development that includes wastewater management, agriculture, and public space. With the possible ending of Cemex operation, an integrated development could become a new employer in the area. The Cemex site also has the capacity to start an alternative sustainable sludge site that could be incorporated in to the waste management solution in a short time period.
Longmont Water Treatment Plant
In this site, both the south and north parts, JTED found a large amount of infrastructure, including tanks and pipe connections, and mechanical component that could be renovated and used as a base for the wastewater treatment plant. We feel that it would be a huge saving both financially and environmentally to avoid demolishing these infrastructure by retrofitting them into a useful form. There are tremendous amounts of expensive infrastructure that could be converted into waste treatment operations at both of the sites. Further analysis is definitely required to assess whether or not one or both of the water plants could be converted to advanced wastewater treatment plants in cost effective manner. It would be rash to state empirically that state of the art systems could be molded from the exiting skeleton of the plants, however in our capacity to observe the viability all of the available sites, both of the plants have lots of potential. The water treatment plants have the possibility to be R&D facilities due to the excess hydraulic capacity at each site. This would bring opportunity to partner with universities and other research based not for profits to advance twenty first century sustainable wastewater and water management.
Eastern Corridor
East to the Longmont water plant, there is a less developed area, which is in the commercial planning zone. This area does not have sewer connection to existing Lyons wastewater treatment facility. This is a potential area for a stand-alone ecological wastewater treatment system, and JTED did not find any constraints to this possibility during this trip. The Eastern Corridor would be a good candidate for a pilot site for Lyons to get started with sustainable wastewater strategies.
Environmental Compliance
Eco-Machines and other natural systems have been operating in the US under EPA oversight since the 1970’s.The present generation of Eco-Machines have evolved to use less land, power and infrastructure. JTED has recently permitted systems in NY, WV and OR, each with system permitted to discharge advanced quality effluent. Two of our last three systems, treated water has been used to flush toilets, therefore having to meet the highest standard for each of those states.
JTED technologies harness the power of nature by working with it. Using biodiversity over pumps, mixers and chemicals, we typically have much lower start up costs and supper low maintenance costs. JTED has also incorporated a triple bottom line consideration, often referred to as People, Place and Profit. When comparing the JTED technologies in either the economical (Profit), environmental (Place) or the social (People), there is nothing that makes more sense to work with water.
The town of Lyons has expressed interest in JTED because of the potential environment impacts this current considerations will have on the environment. Eco-Machines can have a positive environment impact verses a negative one because this systems effluent is balanced with nutrients and enzymes that promote life. Wetlands are natures water filters and by containing the system, we can monitor the water chemistry to achieve the results our country, states, towns and oversight committees consider most important while providing a positive environmental impact. In addition, the system has many potential by-products including educational, economical and certainly environmental. A portion of JTED’s team is dedicated to exploring alternative uses of the WWTP and it’s effluent if the town so chooses to consider it.
Because these systems are easy to modify ongoing, the scalability of these systems are also unparalleled, leaving many unnecessary upfront considerations and related costs differed to the appropriate time.
The Feasibility Study
Due to the complexity and various opportunities in the Town of Lyons wastewater management plan, there needs to be a feasibility study prior to any design work.
The feasibility study should consider one or more of the following:
a. cost analysis of retrofitting the existing facility
b. comparative cost analysis of new technologies and related proposed systems
c. new option proposed by the client.
We highly recommend you consider all the costs related to this system as well. We have incorporated the triple bottom line as part of our Whole Life Costing analysis of our systems as well as others and find it helpful to understand what the true costs are.
It is JTED’s experience that ecological measures can improve the efficiency of the existing wastewater treatment process. The ecological measures can either work alone or be incorporated with necessary physiochemical or mechanical process, depending on the project-specific situation. During the feasibility study, JTED will work closely with all vested parties to find the best solutions.
Take Away Bullet Points
•The existing system could likely be retrofitted for less then the budget proposed by Honeywell. This would be a combination of ecological and conventional technologies.
•The collection system repair is intrinsic to any sustainable solution. Small diameter STEP and STEG systems could provide the town with major capital savings VS conventional sewering.
•Beneficial bacteria cultivated by Hydros, Inc. can be introduced both at the home and the WWT plant. This would have a quantitative reduction of solids at the plant.
•An Eco-Machine system to treat 385,000 gpd, with treatment process comparable to the one at Omega Institute could be built on 4-5 acres, as opposed to the 22 acres stated in the JVA report.
•The water treatment plants are a very interesting opportunity but difficult to quantify without further study.
•The Eastern Corridor would make for an opportune pilot site.
•JTED is open to working with Honeywell or other on solutions for Lyons.
•The Cemex sites have potential for Eco/ Agricultural Parks in addition to waste treatment
Conclusion:
JTED is a solution provider and can work with the town of Lyons to meet their objectives of enhancing the wastewater treatment system. JTED recommends a feasibility study and an analysis of the I&I contributing factors before any sustainable design work can be done. There are at least 4 site locations that could work for our ecological approach, which would be further refined by simply deciding on a few elements such as flexibility, alternative use and public response. We are excited about this project and look forward to designing a truly green solution for the town’s wastewater needs.
