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Effective wastewater management

Effective wastewater management

Alom Poly Extrusions installed the 30.78 km underground drainage network at the Prayag Film City using Alcorr DWC piping system in 95 days.  
Prayag Film City is one of the corporate ventures of The Prayag Group. The City is located in the western periphery of Midnapur district, West Bengal, about 210 km from Kolkata.
The 'City' management decided to build the Internal Roadways and allied underground drainage network on top priority basis and integrate the same with the existing road and other natural/manmade facilities such as river/canal etc. The management realised that installation of the underground drainage network with conventional non-pressure concrete pipes would be exorbitantly time consuming because of infrastructural complexity. They were thriving for a solution to overcome such impasse through alternative techno-com­mercially viable 'Pro­duct and System'. They found their desired solution in the form of Alcorr DWC piping system.
The Film City Complex  
The Film City is an Audio-visual Media Enter­tainment Development Complex, with various sub-centres with multifarious activities, for eg, Miniature city with five-star hotels and resorts. The entire project area comprises 486 acre for conclusive development. Internal roads of 82 km are being constructed in the first phase of project. 

For the smooth solution of the internal drainage related issues, various system alternatives were considered: brick masonry surface drains and conv­entional non-pressure RC piping system. Neither of the alternatives could be put to implementation from drawing boards. Prior to construction of roads, the heavy pipes and ancillary construction materials could not even be transported to the sites and the time lag coupled with complexity of construction prohibited the use of conventional for this application. 

In this backdrop of technological bottleneck, Prayag Group upon discussion with Alom Poly Extrusions, came up with the solution of Alcorr DWC PE pipes to overcome this impasse.   
The product & system
Alcorr double wall polyethylene piping system for non-pressure underground sewerage and drainage applications was considered for installation of their entire drainage and sewerage network.
Applicable codes
The manufacturing, testing, installation and joi­nting of the system complied with all currently applicable industry regulations and global standards. The following international standards are used as specifications for Alcorr piping system.

This particular system outscores the conventional (concrete) sewerage piping systems in all aspects: 

Structural integrity: The overall attributable design load for Alcorr DWC PE piping system shall be remarkably lesser than that of conventional rigid pipes because of flexibility.

Therefore, expensive concrete cradle or encased structural beddings are not required. Such plastic pipes are also safe at lower cushion depths which in turn save substantive installation time and additional installation expenditures. 

Hydraulic capability:
The smooth inner wall of Alcorr DWC PE piping system has very low roughness (Manning's 'N' value of 0.010) in comparison to conventional rigid pipes and therefore the same sized pipes can accommodate much higher flows at identical gradient. Therefore, for particular design discharge, lower sized pipes can be used in comparison to conventional rigid pipe keeping the prescribed gradient identical. Such hydraulic advantage again leads to time and financial savings as well. 

Life: The conventional concrete non-pressure pipes have a material life of 20 years whereas Alcorr pipes and systems last at least for more than 50 years.

Chemical inertness: The material property of Alcorr DWC PE piping system ensures total inertness to all the sewage ingredients and therefore there is no adherence to the internal surfaces of the piping system. This is extremely advantageous from the maintenance pers­pective. This ensures an almost constant 'N' value throughout the material life. In case of conventional rigid pipes the 'roughness coefficient' changes peri­odi­cally because of deposition of solids on inner sur­faces, which eventually reduces the accommodating and tran­sporting capacity of the total network. 

Installation: Its lightness and simple jointing pro­cedure allows for quick and flexible installation inv­olving very little manual labour.
Execution of work
The hydraulic design of the combined sewer network was computed on the basis of the available IFD curve for the designated rainfall frequency pertaining to the location considering the relevant Manning's 'N' value related to the Alcorr  piping system  and in accordance with the Manual on Sewerage & Sewage treatment, CPHEEO, Ministry of Urban Development, Gover­nment of India.
The salient features of the pilot scheme comprising Alcorr piping system are:
135 mm ID:  500 m length
170 mm ID:  1,500 m length
250 mm ID:  5,200 m length
400 mm ID:  12,500 m length
600 mm ID:  7,000 m length
800 mm ID:  3,730 m length
1,000 mm ID:  350 m length
Total network = 30.78 km

The company completed the project within a remarkably short time of 95 days. The client in their certification confirmed: 

'We have reasons to believe that through conve­ntional methodology (RC NP/GSW pipes or surface drains) completion of the project in such short timeframe would never have been possible, concurrently with the road work'. 

The post-implementation monitoring of the perf­ormance of the 'Product and System' is being done meticulously under the perspective of the global stan­dards and the outcome is highly satisfactory.
For effective wastewater management and holistic development of industrial/tourism/hospitality complexes which are inevitably located at lesser developed areas, installation of internal sewerage/drainage network with conventional rigid conduits is extremely difficult and prohibitively time consuming, leading to unplanned extension of project deadlines.  
Instead of conventional systems, if the modern sys­tems such as Alcorr flexible piping systems are adopted, the targeted installation can be achieved in a very short time period without affecting any other ancillary activities. Wastewater management in India can be streamlined if developers look out for the right resources and products that are apt for their required tasks.

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