This project is an Applied/Engineering design that mainly focused on solving the problem of flood and water shortage in STEC campus. This project utilized an effective Drainage system and Filtering system. The timeline was 3 months.
Significance of the Study
One of the major problems inside STEC campus addressed by the STEC community were the unresolved flooding located mainly near the Senior High School canteen area and the lack of water supply. However, through this study, a drainage and filtering system prototype was proposed to provide the following benefits to:
STEC.They will be provided with the drainage and filtering prototype. The prototype can help solving the school’s problem towards flooding and insufficient water supply through demonstrating the process of draining flood water and filtering it. Thus, an alternative water supply for hand-washing toilet uses would also help in conserving fresh water through converting flood water into usable water.
STEC Community. Faculty members, senior high school students, junior high school students, elementary pupils and STEC staff will and at the same time, have more access to usable water.
Department of Science and Technology (DOST). This project may help the said department by inspiring citizens to a eco-friendlier economical and efficient engineering projects that also improves the standards of living.
Department of Education (DepEd). This project may also help the said department in creating a safer school environment for the students. This project may also be guided in the formulation of future modification of engineering-based education, projects and strategies toward more effective learning.
Department of Public Works and Highways (DPWH).This project helps improve better drainage system which also corresponds to the function of DPWH. The project paves way to a more enhanced mechanism not just for drainage in roads and highways as well as incorporating filtration system for more effective governmental utilities.
Local Government Unit (LGU).This project may also benefit to a more operative governmental function that concern the safety and the advancement of the public good or welfare. The project specifically addresses the problem concerning flooding and insufficient water supply as well as poor-drainage system in a certain barangay and local government unit.
Future Researchers. This project can inspire future researchers to produce their own drainage and filtering system that is enhanced with better features. Other future researches can also refer to this project prototype as basis for researches related to drainage and filtering system prototype.
Definition of Terms
In deciphering the terminologies used in this study, the following are defined operationally:
Drainage System- It is a mechanical system to draw water from the flooded area and transporting it to the filtering system of Project Hydra.
Draining Efficiency-It refers on how fast the drainage system gather water from the flood.
Engineering Research- Is the research design being utilized for the Project Hydra.
Filtration System- It is a mechanical system that separates and cleans the flood water from the drainage system.
Filtering Ability – It refers to the quality of Project Hydra to be able to separate and clean solid waste from water.
Flood- refers to the overflow of water in Science and Technology Education Center.
Project Hydra- It refers to the study of solving the problem of water shortage and flood of Science and Technology Education Center.
Prototype- A miniature design of Project Hydra consisting drainage and filtering system in Science and Technology Education Center.
Storage Capacity- It refers to the amount of water that Project Hydra can store.
Water Shortage- It is the problem involving the lack of water supply in Science and Technology Education Center.
Review of Related Literature
This chapter provided an overview of previous research on Drainage and Filtering Systems supplied by Rainwater. This chapter also presented an array of related literature and writing of recognized experts, both of which have significant bearing or relation to the problem under investigation.
Flooding and Water Shortage. Water is a part of everything we do: It feeds crops, powers cities, cools computer servers, and is key to the manufacturing of everything from clothes to cars. According to OECD (2015), the billion more-people expected on the planet by 2025 will increase water demand for all of those functions. And just to feed those people, water withdrawals for agriculture are expected to increase by about half.
But it's not only about the additional mouths to feed; it's also the growth of new appetites. In the study of Rossman (2015), much of the growth in demand will emerge across the developing world. For the first time in history, the share of the global population living in cities recently surpassed 50 percent – on its way to 75 percent expected by 2050.
Based on a study of WWL (2014), with each step up the economic ladder, people demand more water for sanitation, industry, hydroelectric power, and water-intensive diets – such as preferring beef to wheat, a shift that requires 10 times as much water per kilogram to produce. Urban-rural competition for water has already pushed countries to import grains – "virtual water" – or, in the case of wealthier countries like China, South Korea, and Saudi Arabia, to lease land in developing countries.
According to OECD (2015), by 2030, the Water Resources Group forecasts, global water requirements may outstrip sustainable use by 40 percent. And almost half the world's people will be living under severe water stress, predicts the Organization for Economic Cooperation and Development
The concept of flooding has a multi-disciplinary definition based on the interest of the defining discipline. However, Ranzi et al (2012) said, flood is generally taken to include 'any case where land not normally covered by water becomes covered by water. In recent decades there have been raging scientific and media debates on likely changes in flood regimes generated by land-use changes and climate change. In the recent study of Molak (2014) and Jones (2013), the root of most of these debates is centered on the simulated risk from such flood events. These risks are related to human health, infrastructure, socio-economic well-being of affected individuals and damage also to archaeological relics. Methods of evaluating and assessing flood risk have been developed in the field of insurance, technological and environmental fields. Ranzi et al (2012) observed that although river flooding is often related to natural disasters, the impacts of human activities such as urbanization have been observed by many scholars. Merz, et al (2012) and FWMA (2014) agreed that flood risk is expressed in terms of the probability of occurrence of adverse effects of flood related hazards and vulnerability with potential consequences. Consequently, in the study of Merz et al (2012), in the development of an effective and efficient flood risk management strategy factors must be taken into consideration.
Urbanization and flooding are intricately linked in both developed and developing countries. In researches of Parker (2013) and Ranzi et al (2012), the increasing population growth and continued urban expansion has led to a reduction in surface permeability which invariably increases surface runoff in the absence of alleviating urban drainage design. Wheater (2013) noticed that although the UK has only small rivers by world standards, with the tendency for smaller-scale floods to occur considerable economic and infrastructural losses arise from urban flooding. This loss is significantly higher in smaller river bank communities.
Materials for the Project.A rainwater collection and storage system is comprised of many components. To produce good quality water all of the components need to be considered together. According to The Gulf Island Rainwater Connections (n.d), downspouts are where the water needs to be transported horizontally. This piping must be sized for good flows, storm events, and easy cleaning. The Rainwater Connection believes that a series of debris traps and filters and necessary to clean the water as much as possible before it enters storage. For agricultural water a small leaf trap and cleanable pipe systems to catch the larger heavier debris may be all that is required. For potable water systems the water is usually passed through some form of fine mesh screen filter as a final cleaning before entering the storage tank or cistern. A second filtration system will also be used to filter out sediments before using for indoor uses.
Rainwater Harvesting Process (Project Design).In a study of Ling & Benham (2014), Rainwater harvesting is the process of collecting, storing, and later reusing rainwater from surfaces such as roofs. Rainwater harvesting has long been used for agricultural irrigation and as a source of drinking water, and allowed ancient civilizations to flourish in semi-arid and arid regions. Based on the research of Bucklin (2012), harvesting and storing rainwater can reduce the use of municipal and well water. Roofs are often the largest solid surfaces in a residential lot and produce large volumes of water that would enter the system. Intercepting rainwater that falls on roofs can reduce runoff and the need for downstream storm water management and treatment. Rainwater is itself very clean, although contaminants that are present on roof surfaces should be appropriately addressed. As stated by Ward et.al (2012), Rainwater Harvesting Process (RWH) results highlight that the average measured the amount of water saved from the office-based RWH system was 87% across an 8-month period.
In another light from the research of Texas Water Development Board (2014), harvested rainwater can replace tap water for any use. In practice, harvested rainwater is most often used (and permitted for use) for certain designated purposes such as landscape irrigation and toilet flushing. When used for landscape irrigation many states do not require a permit to install a rainwater harvesting system. In rainwater harvesting systems, There are four basic components: 1) Drainage system 2) Screens/filtering system 3) Cisterns/storage 4) Delivery system.
Figure 1.1 Water Harvesting System Project Design
The performance and technical complexity of this simple upflow filter can be increased as much as one likes. It must be noted though that higher filtration rates result in higher buoyancy forces on the filter medium. The top layer of the sand may be spewn up. This can be avoided by covering the filter bed with a metal grate or by raising the depth of the filter bed. In the latter case' though, backwashing by means of simply draining the water in a reversed direction may become increasingly impossible. Conventional backwashing capability may have to be added. Better results may be obtained by using smaller grains and stratified filter beds with decreasing grain size from bottom to top (e.g., 0.7 to 2 mm over a depth of I to 1.5 m).
Drainage system. The Drainage system need gutters and downspouts for rainwater harvesting systems that are essentially no different than convention alone. The only added consideration for a rainwater harvesting system is the number of screens or filtering system that will be needed, since each downspout should have its own.
Screens/Filtering System.For systems designed for non-potable uses such as irrigation and toilet flushing, leaf guards, first flush diverters, and roof washers should provide sufficient treatment alongside a post-filtration system. First flush diverters and roof washers are joined with a pre-filtration system that takes place prior to water entering the tank. According to Rain Harvest LLC (2017), these are typically gravity fed filter systems. Pre-filtration is typically the only filtration required when using the collected rainwater for irrigation. Post-filtration is the filtration that takes place after the collected rainwater has left the tank. Post-filtration systems are typically a pressurized system that filters to a much lower number of microns than typical pre-filters. Post sediment filtration and disinfection is usually required anytime the water will be used for indoor use such as flushing toilets, washing clothes, or shower usage.
Cisterns/Storage. The cistern, or storage tank, stores the collected rainwater for later use and is usually the most expensive component of the system. Cisterns are constructed from many materials such as fiberglass, polypropylene, concrete, or metal. However, they are best made of non-reactive material or, if not, should be lined. Cisterns should be periodically cleaned to remove any accumulated sediments and to discourage algal growth. Cisterns can be located above or belowground; belowground cisterns should be adequately reinforced.
Drainage Efficiency. In a case study of Aronica & Lanza (2015), drainage efficiency, defined as the ratio between the volume drained through the internal sinks and the rainfall volume, varies from a minimum value of 0Ð44 for the synthetic T D 2 years event to a maximum value of 0Ð57 for the 20 October 1999 event. The results of the simulations performed indicate that several inefficiencies of the urban drainage system occur even with all the available inlets working properly at their full capacity (drainage efficiency).
Storage Capacity. Based on the study of Ghisis et al (2014), rainwater tank sizes are also assessed for some cities in order to evaluate the ideal tank capacity as a function of potable water demand and rainwater demand. Results indicate that average potential for potable water savings range from 12% to 79% per year for the cities analysed. Ideal rainwater tank capacities for dwellings with low potable water demand range from about 2000 to 20,000 litres depending on rainwater demand. For dwellings with high potable water demand, ideal rainwater tank capacities range from about 3000 to 7000 litres. The main conclusion drawn from the research is that the average potential for potable water savings in southeastern Brazil is 41%. It was also concluded that rainwater tank capacity has to be determined for each location and dwelling as it depends strongly on potable water demand and rainwater demand.
Filtering Ability. In a study of Cocks et al (2015), the suitable filtration system to be installed will be used to filter the water so that it is fit for human consumption and therefore can be used as drinking water. An inline filtration system will be used as it is faster than slow sand filtration. The water will pass through three filters to sufficiently filter the water for drinking.
Related study 1. In a national study from harvesth2o.com (2013), rainwater harvesting is viewed by many, including the EPA, as a partial solution to the problems posed by water scarcity: droughts and desertification, erosion from runoff, over-reliance on depleted aquifers, and the costs of new irrigation, diversion, and water treatment facilities. Harvested rainwater in the U.S. is used mostly for irrigation; however, there is a growing interest in using rainwater for drinking and other indoor uses. Over 50% of household water
Contaminants in water may include algae, air pollution, bird excrement, and leaves, sand, and dust. Local wells have dealt with these problems for decades. Installation of filtration and purification equipment can remove these contaminants at home as well.
In a project spearheaded by harvesth2o, they first take measures to keep foreign matter out of the incoming rainwater. First flush devices, gutter screens and other screening mechanisms keep the rainwater as clean as possible before it enters the conveyance system. Using screens and filters will greatly reduce maintenance and lengthen the life of the pump and filtration/purification system.
Related study 2. Shareef (2012) said, rainfall harvesting from rural/urban catchments has not received large attention in the US most specifically in Jordan. In the absence of run-off sewer systems in most Jordanian rural and urban areas, rainfall harvesting from roads, parking lots and rooftops can increase water supply for various domestic uses and help combat the chronic water shortages in the country. In this regard, a Roof rainwater harvesting system created by the Jordan government was installed for household water supply.
Results show that a maximum of 15.5 Mm3/y of rainwater can be collected from roofs of residential buildings provided that all surfaces are used and all rain falling on the surfaces is collected. This is equivalent to 5.6% of the total domestic water supply of the year 2005. The potential for water harvesting varies among the governorates, ranging from 0.023×106 m3 for the Aqaba governorate to 6.45×106 m3 for the Amman governorate. The potential for potable water savings was estimated for the 12 governorates, and it ranged from 0.27% to 19.7%. Analysis of samples of harvested rainwater from residential roofs indicated that the measured inorganic compounds generally matched the WHO standards for drinking water. On the other hand, fecal coliform, which is an important bacteriological parameter, exceeded the limits for drinking water.
Related study 3. As stated by Morakinyo et al. (2015), two purpose of utilizing the rainwater harvesting method in Hong Kong is the supplication of water and reduction of temperature. The potential use of rainwater harvesting in conjunction with miscellaneous water supplies and a rooftop garden with rainwater harvesting facility for temperature reduction have been evaluated in this study for Hong Kong. Various water applications such as toilet flushing and areal climate controls have been systematically considered depending on the availability of seawater toilet flushing using the Geographic Information System (GIS). For water supplies, they calculated the district Area Precipitation per Demand Ratio (APDR) to quantify the rainwater utilization potential of each administrative district in Hong Kong. Districts with freshwater toilet flushing prove to have higher potential for rainwater harvest and utilization compared to the areas with seawater toilet flushing. Furthermore, the effectiveness of using rainwater harvesting for miscellaneous water supplies in Hong Kong and Tokyo has been analyzed. In terms of the cooling effect, the implementation of a rooftop rainwater harvesting garden has been evaluated using the ENVI-met model. The results show that a temperature drop of 1.3 °C has been observed due to the rainwater layer in the rain garden. The study provides valuable insight into the applicability of the rainwater harvesting for sustainable water management practice in a highly urbanized city.
Related study 4. As stated by Zhang & Hu (2014), it is urgent to effectively mitigate flood disasters in humid mountainous areas in southeastern China for the increasing flood risk due urbanization and industrialization. In this study, a rural district with an area of 13.39 km2 that planning to build an industrial park covering an area of 7.98 km2 in Changting was selected to estimate the potential of collectable rainwater and the extent to which runoff volume can potentially be mitigated by rainwater harvesting. In addition, the optimum cistern capacity of a rainwater harvesting system in the planned industrial park was evaluated using daily water balance simulation and cost-efficiency analysis. The results showed that rainwater harvesting in the planned industrial park has great potential. The annually collectable rainwater is approximately 9.8 × 106 m3 and the optimum cistern capacity is determined to be 0.9 × 106 m3. With the optimum cistern capacity, the annual rainwater usage rate is 0.99, showing neither financial savings nor deficits. Rainwater harvesting can reduce 100 % of runoff volume in the cases of critical rainfall storm (50 mm) and annual average maximum daily rainfall (111.2 mm), and 58 % of runoff volume in the case of maximum daily rainfall (233.6 mm), respectively. All surface runoff can be collected and stored in the cisterns when rainfall amount is less than 135.5 mm in a rainstorm event.
Related study 5. As stated by Rovira et al. (2014), the population growth will result in increasing water demand, these consequences could potentially jeopardise water resource availability especially in urban areas and will surely be costly. Rainwater harvesting (RWH) systems can aid not only in meeting water demand partially, but also doing so in a more cost-effective and environmentally friendly manner than other techniques. Although the reduction of environmental burdens is fairly obvious, the question for urban planners and consumers remains: are RWH systems economically feasible? This paper investigates cost-effectiveness of eight different scenarios in the Metropolitan Area of Barcelona. To do so, monetary investment is quantified to provide rainwater for laundry purposes. Results indicate that high density scenarios are financially the most suitable choices (higher net present value and shorter payback time) given that: more users mean more savings from laundry additive consumption. Further studies should consider which are the variables that have a greater effect on the financial appraisal. Similar to inflation rate, specific attention should be paid to the costs associated with the storage tank location on this area of the study.
Related study 6. As stated by Li (2012), a plastic-covered ridge and furrow rainfall harvesting (PRFRH) system combined with mulches was designed to increase water availability to crops for improving and stabilizing agricultural production in the semiarid Loess region of northwest China. The system was built by shaping the soil surface with alternate ridges and furrows along the contour. The plastic-covered ridges served as a rainfall harvesting zone and furrows as a planting zone. Some materials were also used to mulch the furrows to increase the effectiveness of the harvested water. This system can make better utilization of light rain by harvesting rainwater through the plastic-covered ridge. Based on the results of this study and other researches, this technique can increase corn grain yield by 60–95% in drought and average years, 70–90% in wet years, and 20–30% in very wet years. The PRFRH system had the potential to increase crop yield and produced greater economic benefit, therefore it could be used in regions dominated by light rainfall of low intensity where crops generally fail due to water stress.
Related study 7. As stated by Wang (2013), in semi-arid areas, crop growth is greatly limited by water. Amount of available water in soil can be increased by surface mulching and other soil management practices. Field experiments were conducted in 2011 and 2012 at Gaolan, Gansu, China, to determine the influence of ridge and furrow rainfall harvesting system (RFRHS), surface mulching and supplementary irrigation (SI) in various combinations on rainwater harvesting, amount of moisture in soil, water use efficiency (WUE), biomass yield of sweet sorghum (Sorghum bicolour L.) and seed yield of maize (Zea mays L.). In conventional fields without RFRHS, gravel-sand mulching produced higher biomass yield than plastic-mulching or straw-mulching. In conclusion, the findings suggested the integrated use of RFRHS, mulching and supplementary irrigation to improve rainwater availability for high sustainable crop yield. However, the high additional costs of supplemental irrigation and construction of RFRHS for rainwater harvesting need to be considered before using these practices on a commercial scale.
Related study 8. As stated by Ward (2012), rainwater harvesting is increasingly becoming an integral part of the sustainable water management toolkit. Despite a plethora of studies modelling the feasibility of the utilisation of rainwater harvesting (RWH) systems in particular contexts, there remains a significant gap in knowledge in relation to detailed empirical assessments of performance. Domestic systems have been investigated to a limited degree in the literature, including in the UK, but there are few recent longitudinal studies of larger non-domestic systems. Additionally, there are few studies comparing estimated and actual performance. Results highlight that the average measured water saving efficiency (amount of mains water saved) of the office-based RWH system was 87% across an 8-month period, due to the system being over-sized for the actual occupancy level. Consequently, a similar level of performance could have been achieved using a smaller-sized tank. Estimated cost savings resulted in capital payback periods of 11 and 6 years for the actual over-sized tank and the smaller optimised tank, respectively.
Related study 9. According to Pubellier (2013), intensive field experiments were conducted from 2006-2011 to examine the effects of massive rainfall to the coastline areas of Mindanao. Integration of drainage system has been carried out for flood prevention functions. The drainage network analysis, based on description and interpretation of drainage anomalies and frequency, allows us to distinguish: (1) subhomogenous drainage areas which correspond to areas bearing consistent geological characteristics, and (2) drainage anomalies. During the scope of time, comparative studies of drainage network installation and its absence have been thoroughly assessed. Drainage network analysis in the coastline of Mindanao indicated less flooding in the said area. After a course of year, incorporation of rainwater harvesting for drainage network was sought to make use of the massive rainfall water during wet seasons. Results indicate efficiency with rainwater harvesting system as it counteracts the underlying problem of water shortage and may target attention as an alternative source of drinking water.
Related study 10. According to Conception (2014), Rainwater harvesting scheme can be applied from integrating the result of runoff experimental plot studies and reservoir inflow analysis resulted to a rainfall–runoff relation. The multi-functionality of agriculture was studied from June to December 2010 in an upland community in Central Luzon, Philippines, by looking across the entire basin of two small water impounding systems or SWIP (Maasin and Buted II).The results indicated that about 85% (i.e., throughfall) of rainfall could reach the ground as vegetations intercept the rest. It was found out that the dominance of rainwater harvesting system is the main component of reservoir inflow, confirming the soil and water conservation, and flood prevention functions of the entire system.
This is an applied/engineering study employing the methods of creation and testing of output. The proposed output was based on the problem in Science and Technology Education Center gathered through a simple profile and qualitative approaches. The proposed prototype Project Hydra (Drainage and Filtering System Prototype) that measures 48x36x12 inches was based on a mechanical-electrical design/program and automated input-output sensor system. Materials was based on the design with reference to machine programming manual. The functionality of the Drainage and Filtering System Prototype was tested based on indicators of: Storage Capacity, Filtration Ability and Drainage Efficiency. The study used purposive sampling to select samples of their perception (rating) of the functionality of the Water Drainage and Filtering System Prototype.
The realization of this study was conducted in two locations: Science and Technology Education Center and Industrial Shop.
Science and Technology Education Center in Basak, Lapu-Lapu City was the chosen location for the needs-based project. Problems were identified in the area and the top problem was the basis of the proposed output. Barangay Masulog was also the site for making and production of the project. The area between the second canteen and TLE model house will be the actual site for the production and installation of the project.
Most materials were bought in the industrial shop located in Poblacion Mercado, Lapu-Lapu City and an electrical shop in Marigondon, Lapu-Lapu City, although some materials were recycled from the houses of the researchers.
A map of Science and Technology Education Center – Basak Campus
The sample respondents from Science and Technology Education Center for the needs-based inquiry of problems and issues of the community were selected through convenient sampling. Fifty (50) Grade-12 respondents were asked of the common problems in the community as they already have sufficient knowledge regarding the test problems of the school.
Another sample respondents from Science and Technology Education Center for the rating of the functionality test of the prototype were selected through purposive sampling. Ten (10) respondents with sufficient knowledge in Robotics answered a Functionality Test rating paper to measure the three quality indicators of the prototype: Drainage Efficiency, Filtering Ability and Storage Capacity.
For the needs-based profiling of the issues in the community, a survey was conducted containing the following queries: What is the major problem inside the STEC campus that requires immediate attention? What do you think would be the solution to this problem?
For the testing of the product based on its indicators: Drainage efficiency, Storage capacity, & Filtration ability, a functionality rating scale was used in a series of schedules (10 testing).
Gathering of Data
1. A needs-based profile, was accomplished, asking the community of their common problems through a survey.
2. The researchers designed a project to solve the problem of the community.
3. The design specified as to its materials and procedure.
4. The researchers worked in the production of the project.
5. The project was tested on the following indicators:
6. The researchers tested the project and a performance/functionality profile tool was used.
The researchers used the following for the treatment of data:
Simple Percentage was used to present the data on the problems in the community.
Performance/functionality profile was used for the test results of the project based on the indicators of functions: storage capacity, filtration ability and drainage efficiency.
Weighted Meanwas used to present the ratings of the functionality of the project.
RESULTS AND DISCUSSION
I-A. The Operation Design – Block Diagram
The operation design of the proposed Project Hydra using ultrasonic sensors, servo and the drainage and filtration system is to reuse and filter excess rainwater that causes flood in the environment. The filtered water will be stored in a water tank with water level indicators that will serve as a water supply for future uses.
Drainage and Filtration System
LED water level indicators
Figure 2.1.1 Block Diagram of Project Hydra
I-B. The Operation Design – Programming
The researcher collected different programs for each sensor from the Arduino website. The codes were compiled and modified to fit the use to be obtained using the Arduino 1.6.9 software. Extensive revision and analysis were done in order to achieve the expected code. Figure 3.1 and3.2 illustrates the program flow chart of the whole project.
Output servo (sweep)
Drainage and Filtration System
Figure 2.1.2 Program Flow Chart of Sensor A
checks for unequal reading in sensor A
Drainage and Filtration System
Output LED level indicator
checks for unequal reading in sensor B
Figure 2.1.3 Program Flowchart of Sensor B
I-C.1 Operation Design – The Set-UpMechanism of Ultrasonic Sensor – Servo Sweep
The Ultrasonic sensor detects the distance of any object without the sense of touch. It is set into repeatable mode, meaning it will continue to detect any object’s distance until it ends. The sensor is given a ten-second calibration time and after that, it runs. If the ultrasonic sensor detects an object closer than 15 cm, then the servo sweep program will run and remove any obstacle away from the drainage entrance.
This sensor contains lenses that determines its detection range. It is said to have a minimum and maximum range of 2 to 400 centimeters according to the manual. The sensor is then set to 15 cm detection range.
Figure 2.1.4. Ultrasonic Sensor Schematic Diagram
Figure 2.1.5 Servo Sensor Schematic Diagram
According to the program, the sensor will only send a high signal when it detects an object or obstruction within 15 cm from the sensor. The system was then tested with varying amounts of blockage at different times. This is to ensure the accuracy of the whole system.
A servo is paired up with the ultrasonic set-up that turns on when the condition is met. Thus, if the ultrasonic sensor picks up blockage, the servo then sweeps the area to eradicate the blockage.