WATER WORKS AND INSURANCE RATES*
The Relation Between Improvements to Water Works and the Decrease of Fire Insurance Rates—Requirements for Water Works in Respect to Fire Protection—The Grading of Cities
I HAVE been asked to talk to you on the relation of water works improvements to fire insurance rates. The word “improvements” implies a condition in which perfection in the water works department has not been attained, and as each city has its own independent problems, we can only speak in generalities of desirable conditions. The classification of a city for the purpose of insurance rating is dependent upon the efficiency not only of the water works but also the fire department, condition of the streets, the general character and construction of buildings, and the enforcement of proper ordinances. With a very few exceptions, the towns and cities of Iowa were classified under the rules of the Western Union Schedule, which has been applied generally in the middle and western states. Recently we have adopted the Standard Grading Schedule of the National Board of Fire Underwriters, but as yet have applied it in only a few instances. This schedule, which brings practically the same results as the former treatment, although more technical in its application, is more susceptible to analysis in many of the details. Further reference will be made to this schedule later on.
Requirements for Water Works Protection
The requirements for water works protection may be briefly outlined as follows:
Source—To be unfailing. If unreliable a storage basin should be provided.
System—First. Gravity System—Supply from an unfailing source with impounding capacity of at least 30 days average domestic consumption.
Second—Combined System—The combined capacity of a reservoir or standpipe and pumps to be 100% greater than the total of the maximum daily consumption and the estimated fire flow.
Third—Direct Pumping System—Pumping capacity to be 100% greater than the total of the maximum daily domestic consumption and the estimated fire flow.
Boilers—To be equal in capacity to that of the pumps. Boiler feed pumps, injectors and steam pipes to pumps to be in duplicate.
Pump House—To be of fire-resistive construction and secure from inundation. Station to be equipped with a recording water pressure gauge.
Filtering Plant—If any, to have a capacity equal to the maximum daily domestic consumption and estimated fire flow unless pumps have direct connection to source of supply or unless the clear water basin has a capacity of at least one day’s maximum domestic consumption.
Pressure—Pressure at pumping station or elevation of reservoir or height of standpipe should be sufficient to force the required fire flow over the highest buildings, unless fire department is provided with steamers.
Fire Flow—The estimated required fire flow ranges in accordance with the population, from 1,000 gallons per minute for a population of 1,0000 inhabitants to about 9,000 gallons per minute for 70 or 75 thousand population. These figures are furnished by a table and are approximate only, the definite amounts to be determined upon inspection, considering the compactness and height of the buildings and values to be protected.
Mains—Main arteries should be ample in size to carry, with moderate frictional loss, the domestic and fire consumption, and should be in duplicate. Mains in the business center and congested manufacturing district should not be less than ten inches in diameter with eight inch cross-connecting mains and in the residential section, not less than eight inches in diameter with six inch cross-connecting mains. Sufficient large feeders should be provided for all sections of the town, insuring suitable circulation, and all systems should be free from dead-ends. No smaller mains than six inches in diameter are recommended.
*Excerpts from a paper read before the Iowa Section, American Water Works Association, at its annual meeting.
Gate Valves—Gate valves to be located at points so that it will not be necessary to shut off from the service more than the length of one block in the congested districts or more than two blocks in the residential section. All branch connections to hydrants should be provided with gate valves. Hydrants—To be “staggered” and should be located from 150 to 300 feet apart in the mercantile and manufacturing district, and from 300 to 600 feet apart in the residential district. Hydrants should have no less than 2½ inch outlets and a steamer connection where steamer service is available. Street connection and riser for hydrants should not be less than six inches in diameter. Hydrants and threads on outlets to conform with the National Standard.
High Pressure System—Water works system to be augmented by a separate system of high pressure pumps and mains to be utilized at times of fire and to be utilized at times of fire and to carry sufficient pressure for direct fire fighting.
Records—Daily statement of consumption and pressure should be made and complete records of pipe, valves, hydrants, etc., to be kept in a fireproof vault.
This, in brief, is an outline of the standard requirements for a first-class city, in so far as the water works department is concerned. The grading for second, third and fourth-class cities are, for the most part, percentages of the requirements for first-class protection. Therefore, any improvements tending to increase the capacities of pumps, pipes, boilers, etc., so as to meet the domestic consumption plus the fire flow will result in better grading of the protection afforded by the water works department.
Of the cities of Iowa, Davenport leads with a secondclass grading. Several cities have been graded as the third-class, while the majority of the water works towns, as is also the case in most states, are fourth-class.
The Grading of Cities
In a city of the third-class, the source of water supply should be standard—or unfailing. The system at least 50 per cent, of the standard; pump house, substantial brick construction, unexposed; boilers, standard, except that duplicate steam pipes to pump are not necessary ; filtering plant, if any, 50 per cent, of standard; pressure and fire flow, standard; mains, in business and manufacturing district, not less than 8-inch with 6-inch cross-connecting mains, and should have sufficiently large feeders to supply suitable circulation for domestic consumption and fire flow—but not necessary to have force mains in duplicate. From this it will be seen that any city having properly fulfilled the requirements for third-class may secure a better grading by providing duplicate force mains and boilers and pumps for reserve purposes, which would increase the reliability of the system. The system in a third-class town merely meets the conditions of domestic consumption and fire flow. Less than that would be three and one-half, or fourthclass, while better would be two and one-half or better, according to the percentage of pumping capacity, boilers and mains in reserve.
The foregoing briefly outlines the standards to be desired for a first-class city, and by variation of efficiency from the standard for second, third and fourthclass cities, which comprise the whole list of water works towns.
Relation Between Water Works Improvements and Insurance Rates
We now come to the relation between water works improvements and fire insurance rates. As the water works is only one department considered in the classification of towns or cities it must be treated in conjunction with the fire department—public fire alarm system —building and general ordinances and streets. For the purpose of comparison, a one-story brick building in a fourth-class town takes a basis rate of 39 cents; in a third-class town, 35 cents; in a second-class town, 31 cents. A one-story frame building in a fourth-class town takes a basis rate of 77 cents; in a third-class town, 71 cents; in a second-class town, 67 cents. The difference in the basis rates between the several classes will figure 13 per cent, on brick or fireproof buildings and 8 per cent, on frame buildings. I have referred to the Standard Grading Schedule of the National Board of Fire Underwriters as one we have adopted for future use. This schedule is based upon the plan of an assumed number of points of variance from established standards.
The total points of definciency is 5,000, allotted in accordance with their relative values as follows:
The deficiencies chargeable to the water works may not exceed 1,700 points. These charges are made on the conditions of variance from standards which, by experience and calculation, are considered necessary for character and congestion of the buildings, areas of builtup sections and population.
These points of definciency are subdivided under the following headings which will be referred to briefly and without analysis.
- Appointment: Employees on municipal systems to be under civil service rules with tenure of office secure.
- Chief Executive: To be competent and qualified by experience.
- Records or Plans: Records and plans of the physical structure and system to be complete, safely filed, in duplicate, indexed and up-to-date.
- Emergency Crews: To be on duty at all times or quickly available. An emergency wagon with necessary tools to be provided. At least one employee familiar with the system should respond to fire alarms in mercantile districts and second alarms elsewhere.
- Alarms: To be installed in department quarters, in pumping stations, and where pressures are raised for hydrant streams, duplicate alarm circuits as to stations.
- Adequacy: As regard Capacity of Source and Supply Works to Deliver Required Supply. In calculating the deficiency under this item results obtained under fire flow tests in the most favorable location are used. Ten hours fire flow in addition to the maximum domestic consumption is desirable in towns of over 2,500 population.
- Reliability of Source of Supply: As may be affected by forest fires, floods, ice dams, shifting of channels, condition of intake.
- Reliability of Pumping Capacity on which supply is dependent.
- Boiler Capacity.
- Condition and Arrangement and Reliability of Plant Equipment.
- Fuel, and Accessories for the Transmission of Power. Pumping Stations.
- Reliability and Installation of Supply Mains.
- Arterial System and Minor Distributors and Gridiron System.
- Gate Valves, as to location, inspection and condition.
- Hydrant Distribution, Size, Installation, and Condition.
It is not the purpose of this paper, nor is it feasible in so brief a time, to enter into all the details of water works engineering, but I have endeavored to show that improvements which will raise a city one full grade of protection will result in a reduction of 8 to 13 per cent, in the basis rates on frame and brick buildings respectively.