While many of us enjoyed being with friends and family, enjoying good food and drink,, how many of us thought about being connected to water and sewer systems that provide safe water supplies and safe wastewater disposal? We should be thankful for this as well. The other option makes life so much harder. We should not water and wastewater for granted, but unfortunately we do.
We hear the moniker about getting the most out of your employees and staff. Business books will talk about accountability, as will politicians, but creating accountability requires a first step on the art of management. In any organization there needs to be a vision of where the organization wants to be in 5, 10 or 20 years. Then there needs to be a team of managers who buy into the vision, and implement it by securing employees who can implement it. But it does not stop there. You need to set expectations. Sounds, easy, but it is one of the issues professional employees especially complain about. Assigning work tasks and saying “get it done” is not an expectation. That’s a command. Commands work in the military, but not so much in private practice. The command and control types are notoriously difficult to work with, especially in professional and/or creative environments. Micro-managers fall into this same mode. The creative/professionals are intelligent and are looking for freedom to solve problems, usually more effectively that they can be told. Instead, what needs to be done is to create a set of expectations of what will be accomplished and timelines. Let the creative types and professionals figure out how. Provide them with the resources they need. If employees understand the expectations, and are given the ability to accomplish the goals, accomplishing them becomes an end in itself – that becomes the goal and their satisfaction. But does it work? Well, yes. I have been in organizations where the stars aligned to have a small group of manager who created and bought into a vision. We set expectations and let people accomplish them. Always faster, always less cost, and always effectively. A degree of recognition follows them. The group was easy to spot because they were accomplishing things (I should note that this does come with the price of jealousy among those who prefer to sit on the sidelines and can create some degree of subterfuge there which requires a strong leader to deal with that problem). Students work the same way – set expectations of the delivery and allow them to develop the methods to solve the problem. It is easy to see who the good engineers are, and who perhaps will be less successful.
Even easier are city and county managers, general managers and the like. New officials come into office and six month later they are complaining that the staff and manager don’t communicate with them. First response is to give them more information, which compounds the problem. Still not communicating. Every manager has one of these stories. The problem is that the new folks never revised the expectations from the past. As a result everyone operates on the last set of expectations, until new ones are established. If that never happens, well, the conflict escalates. Someone has to take the leadership role, which creates a quandary with governing boards like the ones utilities commonly deal with because these folks are generally not educated in the intricacies of the operation of the utility, and rarely have any management experience. They simply do not understand how to set reasonable expectations, to identify what is important to them and what is not, how to delegate, etc. Until a sitdown discussion of expectations of both manager and the board is developed, the potential for friction will exist. Some managers are good at recognizing and making adaptation, but most governing bodies are not. This is why it is important to develop education programs that will encourage the community, which often has better connections to the governing members than staff. So as utilities, our infrastructure is vital to the long-term development of our communities and to the public health and productivity of our residents. So how do we make governing bodies understand the need to invest in utility infrastructure when emergencies are not happening? Realizing we are all busy, we need to keep in mind that outreach is a key to creating that coalition of leadership in the community to advance the utility agenda. Again a leadership issue and the need to engage the community, something we all too often forget to do.
Storms highlight the need to reduce infiltration and inflow into the collection system so as not to overwhelm the piping system causing plant damage or sewage overflows into streets, so much of the focus has been on dealing with removal of infiltration and inflow through televising the sewer system and sealing or lining sections where leaks are noted. However, many miles of videotape show virtually nothing, so significant money is spent to find “nothing.” Part of this is because “infiltration” and “inflow” are not the same, and storm events do not highlight infiltration nearly as much inflow.
The manholes and clean-outs are required for access and removal of material that may build up in the piping system and for changes in direction of the pipe. Manholes are traditionally pre-cast concrete or brick, with brick being the method of choice until the 1960s. Brick manholes suffer from the same problems as vitrified clay sewer lines – the grout is not waterproof so the grout can leak significant amounts of groundwater. The manhole cover may not seal perfectly, becoming another source of infiltration. Pre-cast concrete manholes resolve part this problem, but concrete is not impervious either. While elastomeric or bituminous seals are placed between successive manhole rings, the concrete is still exposed. Many utilities will require the exterior of the manholes to have a coal-tar or epoxy covering the exterior which helps to keep water out.
Inflow results form a direct connection between the sewer system and the surface. The removal or accidental breaking of a cleanout, unsealed manhole covers, laterals on private property, connected gutters or storm ponds, damaged chimneys from paving roads, or cracking of the pipe may be a significant source of inflow to the system. All are potential sources of inflow which can be identified easily during storm events. The peaking that correlates with the rainfall is inflow, not infiltration since infiltration is part of the base flow that creeps upward with time. When operators see peaks, this is not indicative of infiltration which is groundwater. Think inflow. Inflow causes peaks in run time on lift station pumps, and create potential overflows at the plant. The good news is that simple, low tech methods can be used to detect inflow, which should be the precursor to any infiltration investigation.
The following outlines a basic program for inflow detection and correction for any utility system. The order is important, and pursuing all steps will resolve the majority of issues. The first step is inspection of all sanitary sewer manholes for damage, leakage or other problems, which while seeming obvious, usually surprises. The manhole inspection should include documentation of condition, GPS location, and some form of numbering if not currently available. Most manholes have limited condition issues, but where the bench or walls are in poor conditions, that should be repaired with an impregnating resin.
Next is repair/sealing of chimneys in all manholes to reduce inflow from the street during flooding events. The chimney includes the ring, cement extensions, lift rings, brick or cement used to raise the manhole ring. Manhole covers are often disturbed during paving or as a result of traffic. The crack between the ring and cover can leak a lot of water. The intent of the chimney seal is to prevent inflow from the area beneath the rim of the manhole, but above the cone.
The next step is to put dishes into the manholes. One might think that only manholes in low lying areas get water into them, but surprisingly every manhole dish that is properly installed has water in it. Hence assume that all manholes leak water between the rim and cover. Most collection system workers are familiar with dishes at the bottom of the manhole where they are of limited use. This is because the dish deforms when filled with water or is knocked in when the cover is flipped. The solution is a deeper dish with reinforcing ribs. No ribs, don’t use it. A gasket is required.
Once the manholes are sealed, smoke testing can identify obvious surface connections. The normal notifications, inspection and documentation will identify broken or missing cleanout caps, surface breaks on public and private property, connection of gutters to the sewer system, and stormwater connections. All should be documented via photograph, by associated address and public or private location. The public openings at cleanouts can be corrected immediately. However, if the cleanout is broken, it may indicate mower or vehicle damage, that can occur again. If missing, the resident may be using the cleanout to drain the yard. In either case the collection system needs to be protected. USSI (http://www.elastaseal.com/about_us.html), located in Venice, FL developed a solution, called the LDL plug to correct those commonly broken or commonly opened cleanouts to reduce inflow.
Notices should then be sent to property owners with documentation of the inflow connections to their property. This is sometimes the most difficult part of the program due to political will, but it is necessary. This finishes the inflow correction portion of the project, but one more step will help focus efforts for the second “i”.
The final step is a low flow investigation, which is intended to focus on the infiltration piece of the problem. Such an event will take several days and must be planned to determine priority manhole to start with and sequencing.
Based on a projected plan and route:
- Open the manholes
- Inspecting them for flow
- Determining if flow is significant. If investigation of basin will end and new basin will be started. If flow exists, open consecutive manholes upstream to determine where flow is derived from. Generally a 2 inch wide bead of water is a limit of “significant” infiltration.
Documentation of all problems and corrections in a report to utility that identifies problem, location and recommended repair. Identification of sewer system leaks, including those on private property (via location of smoke on private property).
The example in Dania Beach, FL was that the last step indicated that only 15% of the sewer system needed to be televised. This saved the City almost $1.2 million. Their total costs is under $1.4 million for all parts of the project, spread over several years and contracts. Overall the hope is that the inflow and infiltration programs together will save $400,000/yr, a five year payback. But the key is to insure you get the inflow as well as the infiltration… Otherwise storms will continue to overwhelm plants, creating public health concerns and ruining your reuse program.